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Effects of the exposure to ultrafine particles on heart rate in a healthy population
Abstract
The correlation amongst exposure to ultrafine particle concentrations and heart rate in a large healthy population was investigated. The study was conducted by continuously monitoring for seven days fifty volunteers in terms of exposure to particle concentrations, heart rate and physical activity performed through portable monitors. Data were analyzed adopting a linear mixed model able to manage the obtained repeated measures and to recognize a general trend resulting from the subject-specific patterns. Results show that the short-term exposure to ultrafine particle concentrations is positively associated with the heart rate for the different physical activities of the subject investigated (laying down, sitting, standing positions). In particular, a logarithmic correlation was recognized with a sharper increase of about 4-6 bpm for a variation of the particle number concentration of 2 × 104 part/cm3 and a slighter effect for further increases of about 0.1-0.2 × 10-4 bpm/(part/cm).
Capsule:
A positive correlation can be associated between the exposure to ultrafine particles and the heart rate.
... For example, negative associations between exposure to UFPs and HRV were reported by , while Samet et al. (2009) observed positive associations. Rizza et al. (2019) suggested that such discrepancies could result from several factors including the differences in the method of UFP exposure assessment (personal monitors vs. fixed-sites), differences in the type of studied population (adult vs. elder or healthy vs. unhealthy), and the lag time between the HRV recording and the exposure (discrete vs. continuous electrocardiogram (ECG) monitoring). Additionally, the effect of physical activities (standing, sitting, and laying down) and psychological moods during an exposure study may coincide with the impacts of exposure to particles on HR. ...
... The two factors may counteract each other and require further investigations. Heart rate is very much dependent on the position of the individuals (Rizza et al., 2019). Thus, another factor that influencing the HR is the physical activities during cooking, including standing near the stove and the subsequent sitting. ...
... However, to completely understand the relative importance of these coexisting factors, further investigations are needed. Rizza et al. (2019) reported reductions in HR (not statistically significant) while sitting compared to standing suggesting possible reductions in HR during post-cooking period (sitting on sofa) in the present study compared to the cooking period (standing over the stove). The control group simulated cooking with the stove turned off. ...
Cooking is a major source of indoor particulate matter (PM), especially ultrafine particles (UFPs). Long-term exposure to fine and ultrafine particles (UFPs) has been associated with adverse human health effects. Toxicological studies have demonstrated that exposure to PM2.5 (particles with aerodynamic diameter smaller than 2.5 μm) may result in increased blood pressure (BP). Some clinical studies have shown that acute exposure to PM2.5 causes changes in systolic (SBP) and diastolic blood pressure (DBP), depending on the source of particles. Studies assessing the effect of exposure to cooking PM on BP and heart rate (HR) using electric or gas stoves are not well represented in the literature. The aim of this investigation was to perform controlled studies to quantify exposure of 50 healthy volunteer participants to fine and ultrafine particles emitted from a low-emissions recipe for frying ground beef on an electric stove. The BP and heart rate (HR) of the volunteers were monitored during exposure and after the exposure (2 h post-exposure). Maximum UFP and PM2.5 concentrations were 6.5 × 10⁴ particles/cm³ and 0.017 mg/m³, respectively. Exposure to UFPs from frying was associated with statistically significant increases in the SBP. The lack of food and drink during the 2 h post-cooking period was also associated with a statistically significant reduction in SBP. No statistically significant changes in DBP were observed. Physiological factors, including heat stress over the stove and anxiety, could be responsible for an elevation in HR at the early stages of the experiments with a subsequent drop in HR after 90 min post-cooking, when study participants were relaxed sitting in a living room.
... From the geometrical point of view, surgical smoke is mainly made of UltraFine Particles (UFPs) with diameters smaller than 100 nm, which can cause negative side-effects to human health, leading to adverse respiratory and cardiovascular problems Ragde, Jorgensen, and Foreland 2016;Romano et al. 2017;Karjalainen et al. 2018;Brüske-Hohlfeld et al. 2008;Noël et al. 2016;Rizza et al. 2019). In a recent study , the authors measured UFP diameters of surgical smoke obtained during caesarean and orthopaedic surgeries and found it to be between 20 and 100 nm. ...
... Since it has been shown that constant exposure of ORs' occupants to particles with diameters smaller than 100 nm, presents a detrimental effect on the health Ragde, Jorgensen, and Foreland 2016;Romano et al. 2017;Karjalainen et al. 2018;Brüske-Hohlfeld et al. 2008;Noël et al. 2016;Rizza et al. 2019), it is becoming more and more important to investigate concentration levels of UFP inside the OR, which are to date not regulated anywhere in the world. In fact, there are only few studies that have investigated UltraFine particle concentration inside OR, and none, to the authors knowledge, have proposed a fully experimentally validated model of UFP transport in ORs. ...
Air velocity and temperature distributions inside operating rooms (ORs) play a crucial role to reduce the risk of infections and to ensure adequate comfort conditions for patient and medical staff. In this work, the authors have developed a three-dimensional thermo-fluid dynamic model to simulate airflow and thermal comfort in an actual OR equipped with High-Efficiency Particulate Air (HEPA) filters. The model takes into account the presence of surgical lights, people and equipment within the room. An experimental campaign is carried out inside the actual OR to measure velocity and temperature, to be employed as boundary conditions for the numerical model. The experimental data have also been used to validate the numerical results. The validated model has been used to analyze the effects of human shape, thermal boundary conditions and buoyancy forces on the main thermal and fluid dynamic quantities in the OR. The thermal comfort is evaluated based on Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices. The results prove that the present experimental-numerical approach is useful to analyze and improve the thermal comfort conditions for medical staff and patient.
... From the geometrical point of view, surgical smoke is mainly made of UltraFine Particles (UFPs) with diameters smaller than 100 nm, which can cause negative side-effects to human health, leading to adverse respiratory and cardiovascular problems Ragde, Jorgensen, and Foreland 2016;Romano et al. 2017;Karjalainen et al. 2018;Brüske-Hohlfeld et al. 2008;Noël et al. 2016;Rizza et al. 2019). In a recent study , the authors measured UFP diameters of surgical smoke obtained during caesarean and orthopaedic surgeries and found it to be between 20 and 100 nm. ...
... Since it has been shown that constant exposure of ORs' occupants to particles with diameters smaller than 100 nm, presents a detrimental effect on the health Ragde, Jorgensen, and Foreland 2016;Romano et al. 2017;Karjalainen et al. 2018;Brüske-Hohlfeld et al. 2008;Noël et al. 2016;Rizza et al. 2019), it is becoming more and more important to investigate concentration levels of UFP inside the OR, which are to date not regulated anywhere in the world. In fact, there are only few studies that have investigated UltraFine particle concentration inside OR, and none, to the authors knowledge, have proposed a fully experimentally validated model of UFP transport in ORs. ...
... From the geometrical point of view, surgical smoke is mainly made of UltraFine Particles (UFPs) with diameters smaller than 100 nm, which can cause negative side-effects to human health, leading to adverse respiratory and cardiovascular problems Ragde, Jorgensen, and Foreland 2016;Romano et al. 2017;Karjalainen et al. 2018;Brüske-Hohlfeld et al. 2008;Noël et al. 2016;Rizza et al. 2019). In a recent study , the authors measured UFP diameters of surgical smoke obtained during caesarean and orthopaedic surgeries and found it to be between 20 and 100 nm. ...
... Since it has been shown that constant exposure of ORs' occupants to particles with diameters smaller than 100 nm, presents a detrimental effect on the health Ragde, Jorgensen, and Foreland 2016;Romano et al. 2017;Karjalainen et al. 2018;Brüske-Hohlfeld et al. 2008;Noël et al. 2016;Rizza et al. 2019), it is becoming more and more important to investigate concentration levels of UFP inside the OR, which are to date not regulated anywhere in the world. In fact, there are only few studies that have investigated UltraFine particle concentration inside OR, and none, to the authors knowledge, have proposed a fully experimentally validated model of UFP transport in ORs. ...
... Several studies showed cooking as a source of fine and ultrafine particles that can affect brain activity and respiratory and cardiovascular systems [30][31][32][33][34]. Several clinical studies investigated the cardiovascular impact of cooking fumes through inhalation. These studies monitored heart rate [35] and blood pressure [36,32,37] before, during, and several hours after exposure. Some findings reported statistically significant increases in systolic blood pressure (SBP) during the post-exposure period, but no changes in diastolic blood pressure (DBP) were reported. ...
The effect of cooking aerosol on the human heart was investigated in this study. The heart rate and blood pressure of 33 healthy adults were monitored before, exactly after, and two hours post-exposure (30 minutes, 60 minutes, 90 minutes, and 120 minutes after cooking). One hundred twenty grams of ground beef was fried in sunflower oil for twenty minutes using a gas stove without ventilation. Ultrafine particles, indoor temperature, relative humidity, carbon dioxide, oil, and meat temperatures were monitored during the experiment. The average particle emission rate (S) and average decay rate (a+k) for meat frying were found to be 2.09×10¹³ (SD=3.94 ×10¹³, R²=0.98, P <0.0001) particles/min, and 0.055 (SD=0.019, R²=0.91, P <0.0001) particles/min, respectively. No statistically significant changes in diastolic blood pressure (DBP) and heart rate (HR) were observed. The average systolic blood pressure (SBP) statistically significantly increased from 98 mmHg (before the exposure) to 106 mmHg 60 minutes after the exposure. The results suggested that frying emission statistically significantly impacted blood pressure.
... Particulate matter (PM) emissions of PM 2.5 and PM 10 , which refer to particles of aerodynamic diameter smaller than 2.5 μm and 10 μm respectively, can penetrate the respiratory system (Kampa & Castanas, 2008), while there is evidence that particles less than 100 nm are linked to chronic effects and cardiovascular diseases (Miller et al., 2017;Rizza et al., 2019). Road transport is a countable contributor to PM emissions, with 11% of total PM 2.5 emissions and 28% of black carbon (BC) (Ortiz et al., 2019). ...
... Epidemiological and experimental studies have reported compelling evidence that pollution by airborne particulate matter (PM) is an important cause of health outcomes associated with respiratory and cardiovascular diseases as well as cancer mortality [1][2][3][4]. In urban areas, the traffic sector is a major contributor to PM emissions as well as other pollutants, including carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NOX), polycyclic aromatic hydrocarbons (PAHs), and PM [5,6]. ...
Gasoline emissions contain high levels of pollutants, including particulate matter (PM), which are associated with several health outcomes. Moreover, due to the depletion of fossil fuels, biofuels represent an attractive alternative, particularly second-generation biofuels (B2G) derived from lignocellulosic biomass. Unfortunately, compared to the abundant literature on diesel and gasoline emissions, relatively few studies are devoted to alternative fuels and their health effects. This study aimed to compare the adverse effects of gasoline and B2G emissions on human bronchial epithelial cells. We characterized the emissions generated by propane combustion (CAST1), gasoline Surrogate, and B2G consisting of Surrogate blended with anisole (10%) (S+10A) or ethanol (10%) (S+10E). To study the cellular effects, BEAS-2B cells were cultured at air-liquid interface for seven days and exposed to different emissions. Cell viability, oxidative stress, inflammation, and xenobiotic metabolism were measured. mRNA expression analysis was significantly modified by the Surrogate S+10A and S+10E emissions, especially CYP1A1 and CYP1B1. Inflammation markers, IL-6 and IL-8, were mainly downregulated doubtless due to the PAHs content on PM. Overall, these results demonstrated that ultrafine particles generated from biofuels Surrogates had a toxic effect at least similar to that observed with a gasoline substitute (Surrogate), involving probably different toxicity pathways.
... Apart from those findings, there are some instances where different human activities might affect the inhalation rate of UFPs exposure, thereby leading to different health effects. For instance, Rizza et al. (2019) reported different heart-rate change during various physical activities on adult and healthy subjects. Laying down was associated with heart-rate increase of 4.4 × 10 − 4 bpm per 1 #/cm 3 exposure, while sitting and standing could induce around 5.4 × 10 − 4 and 5.7 × 10 − 4 bpm per 1 #/cm 3 . ...
The problem of ultrafine particles (UFPs; PM0.1) has been prevalent since the past decades. In addition to become easily inhaled by human respiratory system due to their ultrafine diameter (<100 nm), ambient UFPs possess various physicochemical properties which make it more toxic. These properties vary based on the emission source profile. The current development of UFPs studies is hindered by the problem of expensive instruments and the inexistence of standardized measurement method. This review provides detailed insights on ambient UFPs sources, physicochemical properties, measurements, and estimation models development. Implications on health impacts due to short-term and long-term exposure of ambient UFPs are also presented alongside the development progress of potentially low-cost UFPs sensors which can be used for future UFPs studies references. Current challenge and future outlook of ambient UFPs research are also discussed in this review. Based on the review results, ambient UFPs may originate from primary and secondary sources which include anthropogenic and natural activities. In addition to that, it is confirmed from various chemical content analysis that UFPs carry heavy metals, PAHs, BCs which are toxic in its nature. Measurement of ambient UFPs may be performed through stationary and mobile methods for environmental profiling and exposure assessment purposes. UFPs PNC esti- mation model (LUR) developed from measurement data could be deployed to support future epidemiological study of ambient UFPs. Low-cost sensors such as bipolar ion and ionization sensor from common smoke detector device may be further developed as affordable instrument to monitor ambient UFPs. Recent studies indicate that short-term exposure of UFPs can be associated with HRV change and increased cardiopulmonary effects. On the other hand, long-term UFPs exposure have positive association with COPD, CVD, CHF, pre-term birth, asthma, and also acute myocardial infarction cases.
... Epidemiological and experimental studies have reported compelling evidence that pollution by airborne particulate matter (PM) is an important cause of health outcomes associated to respiratory and cardiovascular diseases as well as cancer mortalities (Chen et al., 2016;Pope et al., 1995;Rizza et al., 2019;Schraufnagel, 2020). In urban areas, the traffic sector is a major contributor of PM emissions as well as pollutants including carbon monoxide (CO) volatile organic compounds (VOCs), nitrogen oxides (NOX), polycyclic aromatic hydrocarbons (PAHs) and PM . ...
La pollution particulaire constitue aujourd’hui un enjeu sanitaire majeur et est associée au développement de maladies respiratoires et cardiovasculaires. Parmi les différentes fractions, les particules fines (PF) et plus encore les particules ultrafines (PUF), soulèvent une préoccupation croissante. En raison de leur taille, elles peuvent atteindre les voies respiratoires profondes provoquant des conséquences sur la santé à court et à long terme. En milieu urbain, le trafic routier est leur principal émetteur. Aujourd’hui, les transports automobiles utilisent majoritairement des carburants fossiles, carburants qui ne sont pas renouvelables. De ce fait, le développement de nouveaux carburants comme les biocarburants de seconde génération (B2G) pourraient contribuer à diminuer l’utilisation des carburants fossiles et leurs émissions toxiques. Malheureusement, en termes d’effets sanitaires, il existe encore très peu d’études qui s’intéressent aux produits de combustion de ces nouveaux biocarburants.Par conséquent, l’objectif général de ce travail est d’évaluer la toxicité de particules fines et ultrafines produites lors de la combustion de carburants pétroliers et de biocarburants de seconde génération (B2G), pour des conditions de combustion et d’exposition parfaitement contrôlées, représentatives de l’exposition humaine. La première partie de mon travail de thèse a été consacrée au développement d’un protocole d’exposition de cellules pulmonaires adapté à l’étude de particules de combustion, produites de façon reproductible et standardisée, et représentatives de particules issues du trafic routier. Ce protocole a permis la génération et la caractérisation de ces particules ainsi que l’exposition simultanée aux cellules en culture. Une fois validé, ce protocole a permis l’étude du profil de réponse toxique de particules ultrafines riches en carbone organique. La dernière partie de ce travail a été dédiée à l’étude comparative de l’influence du carburant utilisé sur la composition physico-chimique et le profil de réponse toxique observé après exposition aux particules fines et ultrafines.Le développement du protocole d’exposition a permis d’explorer les effets toxicologiques de PUF avec une haute teneur en composés organiques, sur deux modèles de cellules épithéliales bronchiques : le modèle différencié NHBE ainsi que la lignée BEAS-2B. Dans des conditions non cytotoxiques, les deux modèles montrent une induction de la réponse antioxydante et inflammatoire. De plus, le métabolisme des xénobiotiques a également été fortement induit sur la lignée BEAS-2B.Les résultats de l’étude comparative des carburants fossiles et B2G sur la lignée BEAS-2B à des doses d’expositions proches de conditions réelles, montrent également une réponse des marqueurs du stress oxydant, de l’inflammation et du métabolisme des xénobiotiques. Cette réponse est observée principalement 3 h après exposition.L’ensemble de ces résultats démontre l’effet des PF et PUF dans des conditions d’exposition contrôlées sur la réponse antioxydante et inflammatoire ainsi que sur le métabolisme de xénobiotiques. Ces résultats permettront de mieux comprendre l’avenir de nouveaux carburants.
... Higher amplitudes of delta (brain wave with the frequency of 1-3.5 Hz) and theta (brain wave with the frequency of 4.5-7 Hz) were noted in AD patients, especially in the left temporal lobes. 39 Generally, working memory is related to the theta, alpha, and beta bands. 13,19,45 The primary changes in AD patients (mild stage of AD) were associated with increases in theta band power and decreased beta band power compared to a healthy population (HP). ...
Our knowledge of the effects of exposure to indoor ultrafine particles (sub-100 nm, #/cm³) on human brain activity is very limited. The effects of cooking ultrafine particles (UFP) on healthy adults were assessed using an electroencephalograph (EEGs) for brain response. Peak ultrafine particle concentrations were approximately 3 × 10⁵ particle/cm3, and the average level was 1.64 × 10⁵ particle/cm³. The average particle number emission rate (S) and the average number decay rate (a+k) for chicken frying in brain experiments were calculated to be 2.82 × 10¹² (SD = 1.83 × 10¹², R² = 0.91, p = 0.0013) particles/min, 0.47 (SD = 0.30, R² = 0.90, p < 0.0001) min⁻¹, respectively. EEGs were recorded before and during cooking (14 min) and 30 min after the cooking sessions. The brain fast-wave band (beta) decreased during exposure, similar to people with neurodegenerative diseases. It subsequently increased to its pre-exposure condition for 70% of the study participants after 30 min. The brain slow-wave band to fast-wave band ratio (theta/beta ratio) increased during and after exposure, similar to observed behavior in early-stage Alzheimer's disease (AD) patients. The brain then tended to return to its normal condition within 30 min following the exposure. This study suggests that chronically exposed people to high concentrations of cooking aerosol might progress toward AD.
... Therefore, different UFP exposure patterns might explain the inconsistent reports, with some studies showing an association between UFP and changes in the HRV parameters [30][31][32], and other studies finding the opposite [33], while a clear interaction effect by UFP and noise, which we did not observe, is still uncertain. ...
Airport activity causes the emission of particulate matter and noise, two environmental contaminants and potential health hazards, particularly for the personnel operating nearby taxiways. We explored the association between exposure to fine/ultrafine particles (UFPs) and noise with heart rate variability (HRV), an early indicator of cardiovascular autonomic response, among a sample of airport ground staff. Between May and June 2018, thirty-four male operators (mean age = 43 years and SD = 6.7) underwent personal monitoring of exposure to nanoparticles and noise, and HRV during their work activity. We conducted univariate and multivariate analysis to test the effect of UFP and noise exposure HRV. Total Lung Deposition Surface Area (LDSA) was significantly associated with a decrease in HRV Total Power and Triangular index (β = −0.038 p = 0.016 and β = −7.8 × 10−5, p = 0.042, respectively). Noise peak level showed an opposite effect, which was significant for Total Power (β = 153.03, p = 0.027), and for Triangular index (β = 0.362, p = 0.035). Further investigation is warranted to clarify the effect of the concurrent exposure to UFPs and noise on early changes of cardiac autonomic regulation.
... Particulate matter (PM) is among the primary air pollutants, and it is made up of a complex mixture of chemical and biological components (Garcia et al., 2014;Martinello et al., 2014;Schneider et al., 2015Schneider et al., , 2016Ramírez et al., 2019;Rojas et al., 2019;Silva et al., 2020aSilva et al., , 2020bZamberland et al., 2020). Depending on the aerodynamic diameter, particles are divided into coarse, fine, and ultrafine, ranging from nanometers (nm) to microns (μm), being the PM 10 particles with an aerodynamic diameter between 2500 nm and 10000 nm, PM 2.5 particles between 100 nm and 2500 nm, and PM 0.1 particles less than 100 nm (WHO, 2006;Jeong et al., 2017;Clifford et al., 2018;Rizza et al., 2019). More specifically, it has been recognized that particles with a size smaller than 300 nm are considered as atmospheric nanoparticles , and even smaller particle sizes (<100 nm), i.e. ...
Air pollution by particulate matter (PM) is one of the main threats to human health, particularly in large cities where pollution levels are continually exceeded. According to their source of emission, geography, and local meteorology, the pollutant particles vary in size and composition. These particles are conditioned to the aerodynamic diameter and thus classified as coarse (2.5–10 μm), fine (0.1–2.5 μm), and ultrafine (<0.1 μm), where the degree of toxicity becomes greater for smaller particles. These particles can get into the lungs and translocate into vital organs due to their size, causing significant human health consequences. Besides, PM pollutants have been linked to respiratory conditions, genotoxic, mutagenic, and carcinogenic activity in human beings. This document presents an overview of emission sources, physicochemical characteristics, collection and measurement methodologies, toxicity, and existing control mechanisms for ultrafine particles (UFPs) in the last fifteen years.
... Many studies highlighted the link between the exposure to airborne particles and health effects, such as respiratory diseases and inflammation [1], cardiovascular diseases [2,3], diabetes [4], higher systolic blood pressure and pulse pressure [5], and decreased cognitive function in older men [6]; in particular, the World Health Organization (WHO) estimated that the overexposure to particulate matter (PM) causes about 4.2 million deaths per year worldwide [7]. Moreover, the WHO has recently classified PM, referred to as outdoor pollution, as a carcinogenic pollutant for humans (group 1) [8][9][10]. ...
In the present study, the daily dose in terms of submicron particle surface area received by children attending schools located in three different areas (rural, suburban, and urban), characterized by different outdoor concentrations, was evaluated. For this purpose, the exposure to submicron particle concentration levels of the children were measured through a direct exposure assessment approach. In particular, measurements of particle number and lung-deposited surface area concentrations at “personal scale” of 60 children were performed through a handheld particle counter to obtain exposure data in the different microenvironments they resided. Such data were combined with the time–activity pattern data, characteristics of each child, and inhalation rates (related to the activity performed) to obtain the total daily dose in terms of particle surface area. The highest daily dose was estimated for children attending the schools located in the urban and suburban areas (>1000 mm²), whereas the lowest value was estimated for children attending the school located in a rural area (646 mm²). Non-school indoor environments were recognized as the most influential in terms of children’s exposure and, thus, of received dose (>70%), whereas school environments contribute not significantly to the children daily dose, with dose fractions of 15–19% for schools located in urban and suburban areas and just 6% for the rural one. Therefore, the study clearly demonstrates that, whatever the school location, the children daily dose cannot be determined on the basis of the exposures in outdoor or school environments, but a direct assessment able to investigate the exposure of children during indoor environment is essential.
... In the past two decades, the adverse health effects of particulate matter in the air have become widely known (Curtis et al., 2006;Vu et al., 2017;P€ oschl, 2005;Khan et al., 2019;Zeng et al., 2019;Rizza et al., 2019;Naeher et al., 2007;Rem� skar et al., 2015;Brook et al., 2002;Peters et al., 1997). Some of the most recognized sources of particular matter include industrial activities, wood (Naeher et al., 200;Herich et al., 2014) and coal burning, as well as traffic, in particular diesel engines (Jathar et al., 2020;Ning et al., 2013;Rakowska et al., 2014). ...
Use of pyrotechnic articles is a common, though forbidden practice at football matches. While the fans, especially the members of the ultras groups, view pyrotechnic displays as a part of their culture, these devices can be dangerous for the public. In addition to the risks of burning, hand flares and similar items release toxic combustion by-products, including particulate matter – inhaling of which is harmful both for the spectators and players. In order to assess the amounts and composition of the aerosol particles released at a typical event, we performed a study using both a scanning mobility particle sizer and a low-pressure cascade impactor. The number concentration of nanoparticles was clearly correlated with the burning events. Several elements were identified in the collected samples, including heavy metals, while the majority of the sample consisted of amorphous carbon. The nanoparticle number concentration increased up to 12-fold immediately after the beginning of the flares burning, with the largest contribution of particles 155 nm in diameter. The cumulative dose the players inhaled during the match was around 7 × 10⁸ particles/kg, which is 300% higher than the dose one would get in a low-pollution environment. We discuss the results in view of similar pyrotechnical events, especially fireworks.
... resuspension phenomena), whereas sub-micron particles (better described in terms of particle number and black carbon concentrations) may be mostly driven by outdoor-generated pollutants as they represent the aerosol metrics characteristics of secondary atmospheric PM formation and tailpipe traffic emissions Salthammer et al., 2016;Stabile et al., 2017a). These pollutants, unlike CO 2 , can cause serious health effects such as respiratory and cardiovascular problems as well as lung cancer (Buonanno et al., 2013b;Cipolla et al., 2016;Clifford et al., 2018;Gordon et al., 2018;Rizza et al., 2019;Schmid and Stoeger, 2016;Swenberg et al., 2013), thus, their concentration should be monitored and reduced. As an example, outdoor-generated pollutants may results in high concentration in schools when they are located near highly trafficked roads (Rivas et al., 2014;Stabile et al., 2013) due to the high outdoor-to-indoor penetration. ...
Indoor school gyms are environments characterized by high concentrations of different airborne particulate and gaseous pollutants. In particular, like other naturally-ventilated school environments, in addition to indoor pollutants children can be exposed to sub-micron particles and gaseous pollutants emitted by outdoor sources and penetrating the building envelope; moreover, high concentrations of super-micron particles can be reached due to the resuspension phenomena related to the physical activity performed therein. The present paper aims to evaluate the effect of different ventilation methods (natural ventilation, manual airing) and the use of air purifiers in reducing the indoor concentrations of different airborne particles and gaseous pollutants in school gyms. To this end, an experimental campaign was performed in two naturally-ventilated school gyms in Barcelona (Spain) of different volumes and different distance to major urban roads. Indoor and outdoor measurements of particle number, black carbon and PM1-10 concentrations were performed as well as indoor measurements of CO2 and NO2 concentrations. The study revealed that the use of air purifiers with windows kept closed (natural ventilation) can lead to a significant reduction in terms of indoor-to-outdoor concentration ratios. In the smaller gym (air changes per hour of the purifiers, ACH, equal to 9.2 h-1) the I/O ratios were reduced by 93% and 95% in terms of particle number and PM1-10, respectively; whereas in the larger school gym (ACH = 1.7 h-1) the corresponding reductions were 70% and 84%. For manual airing scenarios, the effect of the air purifiers on outdoor-generated sub-micron particles is reduced; in particular, for low ACH values (i.e. ACH = 1.7 h-1), the reduction is quite negligible (6%).
... impaired cognitive development) of particle pollution, due to their greater ventilation per kilogram body weight, dynamic developmental physiology as well as patterns and degree of their exposure (UNICEF, 2016). While there has been growing interest in assessing the health impacts of airborne particulate matter on children (Clifford et al., 2018;Rizza et al., 2018;Evans et al., 2014;Sunyer et al., 2015;Li et al., 2016), there is still a lack of scientific knowledge about UFP exposure, especially in indoor microenvironments (Heinzerling et al., 2016). Clifford et al. (2018) found positive associations between systemic inflammation in children aged 8 to 11 years, and exposure to low levels of ambient UFP (median values between 3 × 10 3 cm −3 and 1.4 × 10 4 cm −3 ) in Brisbane, Australia, where air quality is generally good. ...
Background:
There is a significant lack of scientific knowledge on population exposure to ultrafine particles (UFP) in China to date. This paper quantifies and characterises school children's personal UFP exposure and exposure intensity against their indoor and outdoor activities during a school day (home, school and commuting) in the city of Heshan within the Pearl River Delta (PRD) region, southern China.
Methods:
Time-series of UFP number concentrations and average size were measured over 24 h for 24 children (9-13 years old), using personal monitors over two weeks in April 2016. Time-activity diaries and a questionnaire on the general home environment and potential sources of particles at home were also collected for each participating child. The analysis included concurrently measured size distributions of ambient UFP at a nearby fixed reference site (Heshan Supersite).
Results:
Hourly average UFP concentrations exhibited three peaks in the morning, midday and evening. Time spent indoors at home was found to have the highest average exposure (1.26 × 104 cm-3 during sleeping) and exposure intensity (2.41). While there is always infiltration of outdoor particles indoors (from nearby traffic and general urban background sources), indoor exposure at home was significantly higher than outdoor exposure. Based on the collected questionnaire data, this was considered to be driven predominantly by adults smoking and the use of mosquito repellent incense during the night. Outdoor activities at school were associated with the lowest average exposure (6.87 × 102 cm-3) and exposure intensity (0.52).
Conclusion:
Despite the small sample size, this study characterised, for the first time, children's personal UFP exposure in a city downwind of major pollution sources of the PRD region in China. Particularly, the results highlighted the impact of smoking at home on children's exposure. While the study could not apportion the specific contributions of second hand-smoking and mosquito coil burning, considering the prevalence of smokers among the parents who smoke at home, smoking is a very significant factor. Exposure to second-hand smoke is avoidable, and these findings point out to the crucial role of government authorities and public health educators in engaging with the community on the role of air quality on health, and the severity of the impact of second-hand smoke on children's health.
... Increased ambient levels of fine particulate matter (PM 2.5 , particulate matter with an aerodynamic diameter less than 2.5 µm) are linked to numerous adverse human health effects, including cardiovascular diseases (Bai et al., 2019;Downward et al., 2018;Rizza et al., 2019), premature death Maji, Arora, & Dikshit, 2018), and decreased lung function (Habre et al., 2018;Laumbach & Kipen, 2012). Combustion particles are a major contributor to ambient PM 2.5 , particularly in urban areas (Karagulian et al., 2015). ...
Researchers studying the biological effects of combustion particles typically rely on suspending particles in de-ionized (DI) water, buffer, and/or media prior to in vitro or in vivo experiments. However, the hydrophobic nature of combustion particles makes it difficult to obtain well-suspended, evenly dispersed mixtures, which also makes it difficult to obtain equivalent dosing and endpoint comparisons. This study explored the use of a quartz crystal microbalance (QCM) to measure the mass concentration of combustion particle suspensions. It compared the QCM mass concentration to that estimated by placing a known mass of combustion particles in DI water. It also evaluated the effect of drop volume and combustion particle type on QCM measurements. The results showed that QCM is a promising direct method for measuring suspended combustion particle mass concentrations, and it is particularly effective for quantifying concentrations of difficult-to-suspend particles and for combustion particles placed in polystyrene containers, which can lead to substantial particle losses.
... More and more people begin to pay attention to ambient PM 2.5 concentrations every day, as it is becoming one of the major cause of various diseases, including respiratory and cardiovascular problems [1][2][3]. With the acceleration of industrialization and urbanization, the problem of particulate pollution is becoming increasingly serious, especially in developing countries. ...
The airborne particulate matter has received much attention over the past 20 years because it has become the ninth largest preventable cause of disease in the global population. Therefore, there is a requirement for cost-effective air filters with excellent performance. Electrospun nanofiber membranes are emerging as one of the most versatile air filters for their small pore size distribution. However, it has proven to be extremely challenging to achieve a balance between low filtration resistance and high removal efficiency. Usually, small fiber diameter increases filtration efficiency but this is coupled with high-pressure drop irrespective of the particle size, so negatively influencing quality factor (QF). Herein, a low filtration resistance sandwich structured polyacrylonitrile (PAN) fibrous filters were fabricated through a controlled accumulation of bimodal sized fibers (172 ± 21 nm and 772 ± 118 nm) by alternate needleless electrospinning. The composite membrane possessed a heterogeneity structure and decreased package density, maintaining the same pore size with narrow distribution compared with the membrane consisting of single sized nanofibers. Consequently, the resulting sandwich structured filter after electrostatic removal demonstrates a lower filtration resistance (151.9 Pa) and competitive filtration efficiency (99.89%) to 260 nm mass median diameter sodium chloride (NaCl) aerosol particles compared with the nanofibers structured filter (207.76 Pa, 99.92%) under an airflow velocity of 32 L min⁻¹. Moreover, the composite exhibited the highest QF, as well as excellent mechanical properties and good transmission. Furthermore, the productivity of sandwiched-structure membranes about 20 g h⁻¹, which was several hundred times than traditional electrospinning, offered prospects for industrial production and commercial application. The present investigation may provide a feasible strategy for further improving and optimizing the comprehensive performance of electrospun filters.
Today’s fuels are liquid or gaseous hydrocarbons, possibly with a small proportion of bound oxygen (alcohols), additives, and impurities. An ideal combustion of hydrocarbons oxidizes carbon to carbon dioxide and hydrogen to water. In reality, the exhaust gas from combustion engines contains other pollutants with different health impacts, predominantly as intermediates in incomplete combustion or through the oxidation of natural components of the air (nitrogen) and the fuel (sulfur). These pollutants are primarily particles, carbon monoxide (CO), nitrogen monoxide (NO), nitrogen dioxide (NO2), sulfur oxides (SOx), hydrocarbons, and aldehydes.
The current study investigates gaseous and particulate emissions of a diesel passenger car (Euro 6d-temp), under specific operation events, including diesel particulate filter (DPF) active regeneration. The contribution of DPF active regeneration to sub-23nm volatile and solid particle emissions was investigated in a dedicated measurement campaign. A novel exhaust gas sampling and dilution system was employed for the determination of solid particle number (SPN) emissions down to 23 nm, 10 nm, and 2.5 nm. Total particle number (TPN) emissions, including semi-volatiles, down to 10 nm and down to 5.6 nm were also measured. A DPF active regeneration was triggered during real driving emissions (RDE) testing. DPF regeneration increased NOx and SPN down to 23 nm (SPN23) by 1.7 times and 3 orders of magnitude, respectively, compared to non-regenerating conditions. A second DPF regeneration was triggered during steady-state conditions in the laboratory. Once again, SPN23 emissions were at least 3 orders of magnitude higher compared to normal operation. Under regeneration conditions, SPN down to 2.5 nm (SPN2.5) was 2.3 times higher than SPN23, which suggests that a significant number of particles reside below the regulated limit of 23 nm during DPF regeneration. Moreover, TPN emissions were at least 7 times higher than SPN ones. Both these observations suggest that a significant number of particles during DPF regeneration evades current SPN23 regulation. Based on the DPF active regeneration findings in RDE and lab conditions, the current study introduces an enhanced particulate emission factor that includes the impact of active DPF regenerations.
Rapid and unplanned industrialization and urbanization have led to an increase in air pollutants in the urban areas are not new phenomena. Findings of several pieces of research have shown that at every stage of life beginning from the effect on developing embryo till an older age. A strong relationship has been reported between urban air pollutants with a wide variety of diseases like respiratory diseases, cardiovascular diseases, adverse effects on the nervous system, endocrine system, prevalence of diseases like diabetes, premature births, etc. Highly susceptible groups are the children and elderly, making this problem a serious concern worldwide. Inhalation of an increasing amount of particulate matter with a variety of toxic chemicals adhered to its surface and gaseous pollutants emitted from various sources initiate complex chemical reactions in the body giving rise to several diseases. The particles move through the upper respiratory tract showing its effect in the form of pulmonary inflammation, chronic obstructive pulmonary disease (COPD), moving further affects the heart rate variability (HRV), Ischemic heart disease, crosses the Blood-brain barrier (BBB) leading to mental and behavior disorder as well as insulin resistance leading to diabetes. The health impacts of poor air quality are serious which require urgent attention. This comprehensive review article aims to provide comprehensive information that can be useful for environmentalists, researchers, engineers, and policymakers for incorporating the data for implementing robust action to combat the problem of increasing urban air pollution.
Rapid and unplanned industrialization and urbanization have led to an increase in air pollutants in the urban areas are not new phenomena. Findings of several pieces of research have shown that at every stage of life beginning from the effect on developing embryo till an older age. A strong relationship has been reported between urban air pollutants with a wide variety of diseases like respiratory diseases, cardiovascular diseases, adverse effects on the nervous system, endocrine system, prevalence of diseases like diabetes, premature births, etc. Highly susceptible groups are the children and elderly, making this problem a serious concern worldwide. Inhalation of an increasing amount of particulate matter with a variety of toxic chemicals adhered to its surface and gaseous pollutants emitted from various sources initiate complex chemical reactions in the body giving rise to several diseases. The particles move through the upper respiratory tract showing its effect in the form of pulmonary inflammation, chronic obstructive pulmonary disease (COPD), moving further affects the heart rate variability (HRV), Ischemic heart disease, crosses the Blood-brain barrier (BBB) leading to mental and behavior disorder as well as insulin resistance leading to diabetes. The health impacts of poor air quality are serious which require urgent attention. This comprehensive review article aims to provide comprehensive information that can be useful for environmentalists, researchers, engineers, and policymakers for incorporating the data for implementing robust action to combat the problem of increasing urban air pollution.
Ambient PM2.5 has been proved to be an independent risk factor for cardiovascular diseases; however, little information is available on the age-dependent effects of PM2.5 on the cardiovascular system and the underlying mechanisms following chronic exposure. In this study, multi-aged mice were exposed to PM2.5 via the newly developed real-ambient PM2.5 exposure system to investigate age-related effects on the heart after long-term exposure. First, the chemical and physical properties of PM2.5 used in the exposure system were analyzed. The heart rate of conscious mice was recorded, and results showed that exposure of aged mice to PM2.5 for 26 weeks significantly increased heart rate. Histological analysis and ELISA assays indicated that aged mice were more sensitive to PM2.5 exposure in terms of inducing cardiac oxidative stress and inflammation. Furthermore, untargeted metabolomics revealed that taurine was involved with the PM2.5-induced cardiac dysfunction. The reduced taurine concentration in the heart was examined by LC-MS and imaging mass spectrometry; it may be due to the increased p53 expression level, ROS and inflammatory cytokines. These results emphasize the age-dependent effects of PM2.5 on the cardiovascular system and suggest that taurine may be the novel cardiac effect target for PM2.5-induced heart dysfunction in the aged.
In the present study, the daily dose in terms of particle surface area received by citizens living in different low- and middle-income countries, characterized by different lifestyles, habits, and climates, was evaluated. The level of exposure to submicron particles and the dose received by the populations of Accra (Ghana), Cairo (Egypt), Florianopolis (Brazil), and Nur-Sultan (Kazakhstan) were analyzed. A direct exposure assessment approach was adopted to measure the submicron particle concentration levels of volunteers at a personal scale during their daily activities. Non-smoking adult volunteers performing non-industrial jobs were considered. Exposure data were combined with time-activity pattern data (characteristic of each population) and the inhalation rates to estimate the daily dose in terms of particle surface area.
The received dose of the populations under investigation varied from 450 mm² (Florianopolis, Brazil) to 1300 mm² (Cairo, Egypt). This work highlights the different contributions of the microenvironments to the daily dose with respect to high-income western populations. It was evident that the contribution of the Cooking & Eating microenvironment to the total exposure (which was previously proven to be one of the main exposure routes for western populations) was only 8%–14% for low- and middle-income populations. In contrast, significant contributions were estimated for Outdoor day and Transport microenvironments (up to 20% for Cairo, Egypt) and the Sleeping & Resting microenvironment (up to 28% for Accra, Ghana), highlighting the effects of different site-specific lifestyles (e.g. time-activity patterns), habits, socioeconomic conditions, climates, and outdoor air quality.
Polyoxymethylene dimethyl ether 3 (PODE3) is a highly promising renewable fuel. Not only does it have physical characteristics which are suitable for practical engine applications, but it is also expected to facilitate prominent soot reduction. In this work, neat PODE3 is added to diesel in an engine to evaluate its practicality in terms of curbing aerosol pollution arising from diesel engines, as well as improving energy efficiency for easing global energy shortage. PODE3 has been found capable of offering soot reduction across all engine loads. In particular, 20% of PODE3 addition to diesel has demonstrated soot reduction at all loads, with a remarkable particulate matter reduction factor of 3.55 at 50% load. However, although with such impressive 71.8% soot reduction at medium load, it can cause a spike increase of 71.2% in particle number concentration, owing largely to ultrafine particles. Furthermore, it has been discovered that PODE3 contributes minimal changes to energy efficiency and that the usage of PODE3 has minimal impact on the fuel economy by virtue of PODE3’s high density. Moreover, a manifestation of a nucleation-accumulation mode particle trade-off relationship has been observed in this work. The evaluation of PODE3’s practicality serves to bring into perspective the practicality of the fuel in terms of realistic utilization, to set it in a critical context for providing insights towards future research.
In everyday life, people are exposed to different concentrations of airborne particles depending on the microenvironment where they perform their different activities. Such exposure can lead to high sub-micron particle doses. The received dose depends on particle concentration to which people are exposed (typically expressed in terms of number or surface area), time spent in each activity or microenvironment (time activity pattern) and amount of air inhaled (inhalation rate). To estimate an actual value of the received dose, all these parameters should be measured under real-life conditions; in fact, the concentrations should be measured on a personal scale (i.e. through a direct exposure assessment), whereas time activity patterns and inhalation rates specific to the activity performed should be considered. The difficulties in obtaining direct measurements of these parameters usually lead to adopt time activity patterns and inhalation rates already available in scientific literature for typical populations, and local outdoor particle concentrations measured with fixed monitoring stations and extrapolated for all the other microenvironments.
To overcome these limitations, we propose a full-field method for estimating the received dose of a population sample, in which all the parameters (concentration levels, time activity patterns and inhalation rates) are measured under real-life conditions (also including the inhalation rates, that were evaluated on the basis of the measured heart rates). Specifically, 34 volunteers were continuously monitored for seven days and the data of sub-micron particle concentrations, activities performed, and inhalation rates were recorded. The received dose was calculated with the proposed method and compared with those obtained from different simplified methodologies that consider typical data of particle concentrations, time activity patterns and inhalation rates obtained from literature. The results show that, depending on the methodology used, the differences in the received daily dose can be significant, with a general underestimation of the most simplified method.
The present study numerically and experimentally investigates, for the first time in the literature, the thermo-fluid dynamics and ultrafine particle (UFP) concentration in surgical smoke, with diameters smaller than 100 nm, inside an actual operating room (OR) equipped with a turbulent circular diffuser system. The velocity values and temperature fields measured during the experimental analysis at different points in the OR are in reasonable agreement with the numerical results. For UFP diameters smaller than 70 nm, the particle concentration obtained from the numerical analysis agrees with the experimental data. The numerical results have demonstrated that at the sterile zone, UFP concentration caused by candles smoke is around 1.2×105−1.6×105 particles/cm3, which are exposed by the occupants in OR. UFP decay time of 25 and 20 minutes are obtained in current analysis, respectively, in order to evaluate the time needed by the ventilation system to evacuate the particles from the OR.
Air pollution is a major public health challenge in the highly urbanized megacities of China. However, knowledge on exposure to ambient unregulated air pollutants such as black carbon (BC) and ultrafine particles (UFP) among the Chinese population, especially among urban high school students who may have highly variable time-activity patterns, is scarce. To address this, the personal exposures to BC and UFP of high school students (aged 17 to 18) in Chengdu, China were measured at 1-min intervals via portable samplers. Monitoring lasted for 2 consecutive 24-h periods with days classified as “school days” or “non-school days”. Time-activity diaries and measurements were combined to explore spatial, temporal, and behavioral factors that contribute to different exposure profiles. The overall geometric means of BC and UFP were 3.60 μg/m³ and 1.83 × 10⁴p/cm³, respectively with notable spatiotemporal variation in exposures observed. In general, the household and transport microenvironments were the predominant contributors to total BC (74.5%) and UFP (36.5%) exposure. However, the outdoor public microenvironment was found to have significantly higher overall average levels of BC than the household and transport microenvironments (p < 0.001) while also presenting the greatest exposure dose intensity (EDI – a measure of exposure in a microenvironment in proportion to time spent in that environment) of 4.79. The largest overall average level of UFP occurred in the indoor public microenvironment followed by transport. The outdoor public microenvironment also presented the greatest EDI of UFP (4.17). This study shows notable spatiotemporal variety in exposure patterns and will inform future exposure and population health studies. The high EDI outdoors may mean that health positive activities, such as exercise, may be being undermined by ambient pollution.
Nanoparticles (NPs) are particles of less than or equal to 100 nm in diameter. Due to their size, they have a significant effect on health and safety of people. Capture of these NPs in general ventilation systems by filters remains one of the most widely used means of protection due to its relative simplicity of implementation and its effectiveness for capturing various size of particles. In North America, filters used in general ventilation systems are tested by the ANSI/ASHRAE Standard 52.2 and are graded according to their efficiency, which is a function of particle diameter. However, the current standard limits the filtration efficiency assessment for particles between 0.3 and 10.0 µm. There is therefore a significant lack of knowledge about the behavior of these filters with respect to the particle diameter below 0.3 µm considering the overall filter used in general ventilation. The main objective of this study was to develop a measurement procedure to evaluate the effectiveness of mechanical filters used in general ventilation systems against NPs. In this regard, a small setup was designed, build and qualified. Then measurement procedure was validated by comparing the penetration measurements with those obtained on qualified big loop setup for nanoparticles, which was inspired by ASHRAE. One type of mechanical filter rated (MERV 8) in three depth sizes (2.54, 5.08 and 10.16 cm) was used to compare the penetrations. The obtained results are consistent with the classical filtration theory for mechanical media and with previous experimental measurements on media. The data presented in this study show that the penetration range of 0.7-1.0 obtained for particle range 22.1-294.3 nm and at 1.00 and 0.75 m/s gives a fairly good correlation (R2 = 0.898) between the two setups. The outcome results validate the methodology used to evaluate the effectiveness of one mechanical filter used in general ventilation systems against nanoparticles by using the small setup.
A comparative study of the effects of ethanol/diesel (DE) and n-pentanol/diesel (DP) blends on the engine performance and emission in a direct-injection diesel engine was carried out. Results show that brake specific fuel consumption increases with increasing alcohol fraction for both DE and DP fuel blends. Nevertheless, DE and DP fuel additions show no significant influence on brake thermal efficiency. Besides, ethanol and/or n-pentanol slightly increase the brake specific gaseous pollutant emissions such as the brake specific total unburned hydrocarbon (BSHC), carbon monoxide (BSCO) and nitrogen oxides (BSNOx), while dramatically reduce particulate emissions. The DE and DP blends show approximately the same level of BSCO and BSHC emissions, while DP blends result in slightly higher BSNOx and particulate emissions. A detailed kinetic model was proposed to calculate the soot formation precursors such as benzene and pyrene. Modeling results show that the length of carbon chain has only slight effect on soot reduction under relatively low oxygen mass content, while ethanol/diesel blend exhibits lower soot formation under high oxygen concentration.
Background:
There is relatively little evidence of health effects of long-term exposure to traffic-related pollution in susceptible populations. We investigated whether long-term exposure to traffic air and noise pollution was associated with all-cause mortality or hospital readmission for myocardial infarction (MI) among survivors of hospital admission for MI.
Methods:
Patients from the Myocardial Ischaemia National Audit Project database resident in Greater London (n=18,138) were followed for death or readmission for MI. High spatially-resolved annual average air pollution (11 metrics of primary traffic, regional or urban background) derived from a dispersion model (resolution 20m×20m) and road traffic noise for the years 2003-2010 were used to assign exposure at residence. Hazard ratios (HR, 95% confidence interval (CI)) were estimated using Cox proportional hazards models.
Results:
Most air pollutants were positively associated with all-cause mortality alone and in combination with hospital readmission. The largest associations with mortality per interquartile range (IQR) increase of pollutant were observed for non-exhaust particulate matter (PM10) (HR=1.05 (95% CI 1.00, 1.10), IQR=1.1μg/m(3)); oxidant gases (HR=1.05 (95% CI 1.00, 1.09), IQR=3.2μg/m(3)); and the coarse fraction of PM (HR=1.05 (95% CI 1.00, 1.10), IQR=0.9μg/m(3)). Adjustment for traffic noise only slightly attenuated these associations. The association for a 5dB increase in road-traffic noise with mortality was HR=1.02 (95% CI 0.99, 1.06) independent of air pollution.
Conclusions:
These data support a relationship of primary traffic and regional/urban background air pollution with poor prognosis among MI survivors. Although imprecise, traffic noise appeared to have a modest association with prognosis independent of air pollution.
The health effects of short-term exposure to ambient ultrafine particles in micro-environments are still under investigation.
Sixty-four individuals with type 2 diabetes and impaired glucose tolerance recorded ambulatory electrocardiograms over five to six hours on 191 occasions in a panel study in Augsburg, Germany. Personal exposure to particle number concentrations (PNC) was monitored for each individual on 5-minute basis concurrently and particulate matter with an aerodynamic diameter < 2.5 μm (PM2.5) was acquired from a central monitoring site on an hourly basis.
More than 11,000 5-minute intervals were available for heart rate and measures of heart rate variability including SDNN (standard deviation of NN intervals). A concurrent decrease in 5-minute SDNN of −0.56% (95% confidence limits (CI): −1.02%; −0.09%) and a 5-minute delayed increase in heart rate of 0.23 % (95% CI: 0.11%; 0.36%) was observed with an increase in personal PNC of 16,000 per cm3 in additive mixed models. Models evaluating the association of concurrent 5-minute personal PNC and of 1-hour PM2.5 showed independent effects on SDNN.
The data suggest that freshly emitted ultrafine particles and aged fine particulate matter are both associated with changes in cardiac function in individuals with type 2 diabetes and impaired glucose tolerance in urban areas.
Background
Particles in smaller size fractions, such as ultrafine particles (UFPs) (with diameter less than 100 nm), has become of significant cardiovascular health concerns. However, the biological plausibility underlying potential relationship between UFPs and cardiovascular outcomes is less studied.
Methods
Fifty-three subjects living in Shanghai with type-2 diabetes (T2D) or impaired glucose tolerance (IGT) were followed for autonomic dysfunctions with three repeated measurements in 2010. Minute-to-minute concentrations of ambient particles in small size-fractions (5-560 nm), black carbon (BC), sulfur dioxide (SO 2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) were monitored using a central monitoring laboratory equipped with real-time air monitors close to residential area of the subjects. Generalized linear mixed models, with adjustment for individual risk factors, were applied to assess the effects of air pollution on autonomic dysfunctions in subjects.
Results
Our study showed that significant reduction in the standard deviation of all NN intervals (SDNN) ranging from 3.4% to 8.1% were associated with interquartile range (IQR) increase of number concentration of particles (PNC) in size fractions <100 nm, and reduction from 1.3% to 4.6% with particles of diameter 100-200 nm, in subjects with diabetes or glucose tolerance. Increased exposure to traffic-related pollutants BC, NO2 and CO, and combustion pollutant SO2, were also significantly associated with HRV reductions. However, no effect was observed for particles in size fraction of 200-560 nm and O3. Diabetic risk factor and gender appeared to have significant interactions on autonomic dysfunction associated with UFPs and traffic pollution exposures in certain time-window.
Conclusions
Our results suggest that underlying diabetes or impaired glucose tolerance may confer reduced autonomic function of heart due to traffic pollution exposure.
BACKGROUND: For many individuals, daily commuting activities on roadways account for a substantial proportion of total exposure, as well as peak-level exposures, to traffic-related air pollutants (TRAPS) including ultrafine particles, but the health impacts of these exposures are not well-understood. We sought to determine if exposure to TRAPs particles during commuting causes acute oxidative stress in the respiratory tract or changes in heart rate variability (HRV), a measure of autonomic activity.
Ambient air pollution (AAP) and particulate matters (PM) have been closely associated with adverse health effects such as respiratory disease and cardiovascular diseases. Previous studies have examined the adverse health effects associated with short- and long-term exposure to AAP and outdoor PM on respiratory disease. However, the effect of PM size (PM2.5 and PM10) on cardiovascular disease has not been well studied. Thus, it remains unclear how the size of the inhalable particles (coarse, fine, or ultrafine) affects mortality and morbidity. Airborne PM concentrations are commonly used for ambient air quality management worldwide, owing to the known effects on cardiorespiratory health. In this article, we assess the relationship between cardiovascular diseases and PM, with a particular focus on PM size. We discuss the association of PM2.5 and PM10, nitrogen dioxide (NO2), and elemental carbon with mortality and morbidity due to cardiovascular diseases, stroke, and altered blood pressure, based on epidemiological studies. In addition, we provide evidence that the adverse health effects of AAP and PM are more pronounced among the elderly, children, and people with preexisting cardiovascular and respiratory conditions. Finally, we critically summarize the literature pertaining to cardiovascular diseases, including atherosclerosis and stroke, and introduce potential studies to better understand the health significance of AAP and PM on cardiovascular
disease.
Background
Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ¿100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects.Methods17 never-smoker subjects 30¿60 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (0¿10 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure.ResultsAnalysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heart rate variability with UFP relative to air exposure (p¿=¿0.014), paralleled by non-significant reductions in time-domain heart rate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heart rate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heart rate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p¿=¿0.045). There were no UFP effects on cardiac rhythm or repolarization.Conclusions
Inhalation of elemental carbon ultrafine particles alters heart rate and heart rate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure.
Maximum likelihood or restricted maximum likelihood (REML) estimates of the
parameters in linear mixed-effects models can be determined using the lmer
function in the lme4 package for R. As for most model-fitting functions in R,
the model is described in an lmer call by a formula, in this case including
both fixed- and random-effects terms. The formula and data together determine a
numerical representation of the model from which the profiled deviance or the
profiled REML criterion can be evaluated as a function of some of the model
parameters. The appropriate criterion is optimized, using one of the
constrained optimization functions in R, to provide the parameter estimates. We
describe the structure of the model, the steps in evaluating the profiled
deviance or REML criterion, and the structure of classes or types that
represents such a model. Sufficient detail is included to allow specialization
of these structures by users who wish to write functions to fit specialized
linear mixed models, such as models incorporating pedigrees or smoothing
splines, that are not easily expressible in the formula language used by lmer.
Background
While air pollution exposures have been linked to cardiovascular outcomes, the contribution from acute gas and particle traffic-related pollutants remains unclear. Using a panel study design with repeated measures, we examined associations between personal exposures to traffic-related air pollutants in Mexico City and changes in heart rate variability (HRV) in a population of researchers aged 22 to 56 years.
Methods
Participants were monitored for approximately 9.5 hours for eight days while operating a mobile laboratory van designed to characterize traffic pollutants while driving in traffic and “chasing” diesel buses. We examined the association between HRV parameters (standard deviation of normal-to-normal intervals (SDNN), power in high frequency (HF) and low frequency (LF), and the LF/HF ratio) and the 5-minute maximum (or average in the case of PM2.5) and 30-, 60-, and 90-minute moving averages of air pollutants (PM2.5, O3, CO, CO2, NO2, NOx, and formaldehyde) using single- and two-pollutant linear mixed-effects models.
Results
Short-term exposure to traffic-related emissions was associated with statistically significant acute changes in HRV. Gaseous pollutants – particularly ozone – were associated with reductions in time and frequency domain components (α = 0.05), while significant positive associations were observed between PM2.5 and SDNN, HF, and LF. For ozone and formaldehyde, negative associations typically increased in magnitude and significance with increasing averaging periods. The associations for CO, CO2, NO2, and NOx were similar with statistically significant associations observed for SDNN, but not HF or LF. In contrast, PM2.5 increased these HRV parameters.
Conclusions
Results revealed an association between traffic-related PM exposures and acute changes in HRV in a middle-aged population when PM exposures were relatively low (14 μg/m3) and demonstrate heterogeneity in the effects of different pollutants, with declines in HRV – especially HF – with ozone and formaldehyde exposures, and increases in HRV with PM2.5 exposure. Given that exposure to traffic-related emissions is associated with increased risk of cardiovascular morbidity and mortality, understanding the mechanisms by which traffic-related emissions can cause cardiovascular disease has significant public health relevance.
Efforts to understand and mitigate the health effects of particulate matter (PM) air pollution have a rich and interesting history. This review focuses on six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There has been substantial progress in the evaluation of PM health effects at different timescales of exposure and in the exploration of the shape of the concentration-response function. There has also been emerging evidence of PM-related cardiovascular health effects and growing knowledge regarding interconnected general pathophysiological pathways that link PM exposure with cardiopulmonary morbidity and mortality. Despite important gaps in scientific knowledge and continued reasons for some skepticism, a comprehensive evaluation of the research findings provides persuasive evidence that exposure to fine particulate air pollution has adverse effects on cardiopulmonary health. Although much of this research has been motivated by environmental public health policy, these results have important scientific, medical, and public health implications that are broader than debates over legally mandated air quality standards.
Background: Mechanisms underlying previously reported air pollution and cardiovascular (CV) morbidity associations remain poorly understood.
Objectives: We examined associations between markers of pathways thought to underlie these air pollution and CV associations and ambient particle concentrations in postinfarction patients.
Methods: We studied 76 patients, from June 2006 to November 2009, who participated in a 10-week cardiac rehabilitation program following a recent (within 3 months) myocardial infarction or unstable angina. Ambient ultrafine particle (UFP; 10–100 nm), accumulation mode particle (AMP; 100–500 nm), and fine particle concentrations (PM2.5; ≤ 2.5 μm in aerodynamic diameter) were monitored continuously. Continuous Holter electrocardiogram (ECG) recordings were made before and during supervised, graded, twice weekly, exercise sessions. A venous blood sample was collected and blood pressure was measured before sessions.
Results: Using mixed effects models, we observed adverse changes in rMSSD [square root of the mean of the sum of the squared differences between adjacent normal-to-normal (NN) intervals], SDNN (standard deviation of all NN beat intervals), TpTe (time from peak to end of T-wave), heart rate turbulence, systolic and diastolic blood pressures, C-reactive protein, and fibrinogen associated with interquartile range increases in UFP, AMP, and PM2.5 at 1 or more lag times within the previous 5 days. Exposures were not associated with MeanNN, heart-rate–corrected QT interval duration (QTc), deceleration capacity, and white blood cell count was not associated with UFP, AMP, and PM2.5 at any lag time.
Conclusions: In cardiac rehabilitation patients, particles were associated with subclinical decreases in parasympathetic modulation, prolongation of late repolarization duration, increased blood pressure, and systemic inflammation. It is possible that such changes could increase the risk of CV events in this susceptible population.
Short-term exposure to high levels of air pollution may trigger myocardial infarction (MI), but this association remains unclear.
To assess and quantify the association between short-term exposure to major air pollutants (ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter ≤10 μm [PM(10)] and ≤2.5 μm [PM(2.5)] in diameter) on MI risk.
EMBASE, Ovid MEDLINE in-process and other nonindexed citations, and Ovid MEDLINE (between 1948 and November 28, 2011), and EBM Reviews-Cochrane Central Register of Controlled Trials and EBM Reviews-Cochrane Database of Systematic Reviews (between 2005 and November 28, 2011) were searched for a combination of keywords related to the type of exposure (air pollution, ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, PM(10), and PM(2.5)) and to the type of outcome (MI, heart attack, acute coronary syndrome).
Two independent reviewers selected studies of any study design and in any language, using original data and investigating the association between short-term exposure (for up to 7 days) to 1 or more air pollutants and subsequent MI risk. Selection was performed from abstracts and titles and pursued by reviewing the full text of potentially eligible studies.
Descriptive and quantitative information was extracted from each selected study. Using a random effects model, relative risks (RRs) and 95% CIs were calculated for each increment of 10 μg/m(3) in pollutant concentration, with the exception of carbon monoxide, for which an increase of 1 mg/m(3) was considered.
After a detailed screening of 117 studies, 34 studies were identified. All the main air pollutants, with the exception of ozone, were significantly associated with an increase in MI risk (carbon monoxide: 1.048; 95% CI, 1.026-1.070; nitrogen dioxide: 1.011; 95% CI, 1.006-1.016; sulfur dioxide: 1.010; 95% CI, 1.003-1.017; PM(10): 1.006; 95% CI, 1.002-1.009; and PM(2.5): 1.025; 95% CI, 1.015-1.036). For ozone, the RR was 1.003 (95% CI, 0.997-1.010; P = .36). Subgroup analyses provided results comparable with those of the overall analyses. Population attributable fractions ranged between 0.6% and 4.5%, depending on the air pollutant.
All the main air pollutants, with the exception of ozone, were significantly associated with a near-term increase in MI risk.
Few studies have examined the acute health effects of air pollution exposures experienced while cycling in traffic.
We conducted a crossover study to examine the relationship between traffic pollution and acute changes in heart rate variability. We also collected spirometry and exhaled nitric oxide measures.
Forty-two healthy adults cycled for 1 hr on high- and low-traffic routes as well as indoors. Health measures were collected before cycling and 1-4 hr after the start of cycling. Ultrafine particles (UFPs; ≤ 0.1 μm in aerodynamic diameter), particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5), black carbon, and volatile organic compounds were measured along each cycling route, and ambient nitrogen dioxide (NO2) and ozone (O3) levels were recorded from a fixed-site monitor. Mixed-effects models were used to estimate associations between air pollutants and changes in health outcome measures relative to precycling baseline values.
An interquartile range increase in UFP levels (18,200/cm3) was associated with a significant decrease in high-frequency power 4 hr after the start of cycling [β = -224 msec2; 95% confidence interval (CI), -386 to -63 msec2]. Ambient NO2 levels were inversely associated with the standard deviation of normal-to-normal (NN) intervals (β = -10 msec; 95% CI, -20 to -0.34 msec) and positively associated with the ratio of low-frequency to high-frequency power (β = 1.4; 95% CI, 0.35 to 2.5) 2 hr after the start of cycling. We also observed significant inverse associations between ambient O3 levels and the root mean square of successive differences in adjacent NN intervals 3 hr after the start of cycling.
Short-term exposures to traffic pollution may contribute to altered autonomic modulation of the heart in the hours immediately after cycling.
Air pollution is increasingly recognized as an important and modifiable determinant of cardiovascular disease in urban communities. Acute exposure has been linked to a range of adverse cardiovascular events including hospital admissions with angina, myocardial infarction, and heart failure. Long-term exposure increases an individual's lifetime risk of death from coronary heart disease. The main arbiter of these adverse health effects seems to be combustion-derived nanoparticles that incorporate reactive organic and transition metal components. Inhalation of this particulate matter leads to pulmonary inflammation with secondary systemic effects or, after translocation from the lung into the circulation, to direct toxic cardiovascular effects. Through the induction of cellular oxidative stress and proinflammatory pathways, particulate matter augments the development and progression of atherosclerosis via detrimental effects on platelets, vascular tissue, and the myocardium. These effects seem to underpin the atherothrombotic consequences of acute and chronic exposure to air pollution. An increased understanding of the mediators and mechanisms of these processes is necessary if we are to develop strategies to protect individuals at risk and reduce the effect of air pollution on cardiovascular disease.
We investigated associations between ambient pollution levels and cardiovascular function in a repeated measures study including 163 observations on twenty-one 53- to 87-year-old active Boston residents observed up to 12 times from June to September 1997. Particles with aerodynamic diameter </=2.5 microm (PM(2.5)) were measured continuously using a tapered element oscillating microbalance.
The protocol involved 25 minutes per week of continuous Holter ECG monitoring, including 5 minutes of rest, 5 minutes of standing, 5 minutes of exercise outdoors, 5 minutes of recovery, and 20 cycles of slow breathing. Heart rate variability (HRV) was assessed through time domain variables: the standard deviation of normal RR intervals (SDNN) and the square root of the mean of the squared differences between adjacent normal RR intervals (r-MSSD). Mean 4-hour PM(2.5) levels ranged from 3 to 49 microg/m(3); 1-hour ozone levels ranged from 1 to 77 ppb. In multivariate analyses, significantly less HRV (SDNN and r-MSSD) was associated with elevated PM(2.5). During slow breathing, a reduction in r-MSSD of 6.1 ms was associated with an interquartile (14.3 microg/m(3)) increase in PM(2.5) during the hour of and the 3 hours previous to the Holter session (P=0.006). During slow breathing, a multiple pollution model was associated with a reduction in r-MSSD of 5.4 ms (P=0.02) and 5.5 ms (P=0.03) for interquartile changes in PM(2.5) and ozone, respectively, resulting in a combined effect equivalent to a 33% reduction in the mean r-MSSD.
Particle and ozone exposure may decrease vagal tone, resulting in reduced HRV.
We conducted a study on two panels of human subjects--9 young adults and 10 elderly patients with lung function impairments--to evaluate whether submicrometer particulate air pollution was associated with heart rate variability (HRV). We measured these subjects' electrocardiography and personal exposure to number concentrations of submicrometer particles with a size range of 0.02-1 microm (NC0.02-1) continuously during daytime periods. We used linear mixed-effects models to estimate the relationship between NC0.02-1 and log10-transformed HRV, including standard deviation of all normal-to-normal intervals (SDNN), square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD), low frequency (LF, 0.04-0.15 Hz), and high frequency (HF, 0.15-0.40 Hz), adjusted for age, sex, body mass index, tobacco exposure, and temperature. For the young panel, a 10,000-particle/cm3) increase in NC0.02-1 with 1-4 hr moving average exposure was associated with 0.68-1.35% decreases in SDNN, 1.85-2.58% decreases in r-MSSD, 1.32-1.61% decreases in LF, and 1.57-2.60% decreases in HF. For the elderly panel, a 10,000-particle/cm3 increase in NC0.02-1 with 1-3 hr moving average exposure was associated with 1.72-3.00% decreases in SDNN, 2.72-4.65% decreases in r-MSSD, 3.34-5.04% decreases in LF, and 3.61-5.61% decreases in HF. In conclusion, exposure to NC0.02-1 was associated with decreases in both time-domain and frequency-domain HRV indices in human subjects.
Efforts to understand and mitigate thehealth effects of particulate matter (PM) air pollutionhave a rich and interesting history. This review focuseson six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There hasbeen substantial progress in the evaluation of PM health effects at different time-scales of exposure and in the exploration of the shape of the concentration-response function. There has also been emerging evidence of PM-related cardiovascular health effects and growing knowledge regarding interconnected general pathophysiological pathways that link PM exposure with cardiopulmonary morbidiity and mortality. Despite important gaps in scientific knowledge and continued reasons for some skepticism, a comprehensive evaluation of the research findings provides persuasive evidence that exposure to fine particulate air pollution has adverse effects on cardiopulmonaryhealth. Although much of this research has been motivated by environmental public health policy, these results have important scientific, medical, and public health implications that are broader than debates over legally mandated air quality standards.
The biological mechanisms linking air pollution to cardiovascular events still remain largely unclear.
To investigate whether biological mechanisms linking air pollution to cardiovascular events occurred concurrently in human subjects exposed to urban air pollutants.
We recruited a panel of 76 young, healthy students from a university in Taipei. Between April and June of 2004 or 2005, three measurements were made in each participant of high-sensitivity C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG), plasminogen activator fibrinogen inhibitor-1 (PAI-1), tissue-type plasminogen activator (tPA) in plasma, and heart rate variability (HRV). Gaseous air pollutants were measured at one air-monitoring station inside their campus, and particulate air pollutants were measured at one particulate matter supersite monitoring station 1 km from their campus. We used linear mixed-effects models to associate biological endpoints with individual air pollutants averaged over 1- to 3-day periods before measurements were performed.
We found that increases in hs-CRP, 8-OHdG, fibrinogen, and PAI-1, and decreases in HRV indices were associated with increases in levels of particles with aerodynamic diameters less than 10 microm and 2.5 microm, sulfate, nitrate, and ozone (O(3)) in single-pollutant models. The increase in 8-OHdG, fibrinogen, and PAI-1, and the reduction in HRV remained significantly associated with 3-day averaged sulfate and O(3) levels in two-pollutant models. There were moderate correlations (r = -0.3) between blood markers of hs-CRP, fibrinogen, PAI-1, and HRV indices.
Urban air pollution is associated with inflammation, oxidative stress, blood coagulation and autonomic dysfunction simultaneously in healthy young humans, with sulfate and O(3) as two major traffic-related pollutants contributing to such effects.
Schools represent a critical microenvironment in terms of air quality due to the proximity to outdoor particle sources and the frequent lack of proper ventilation and filtering systems. Moreover, the population exposed in schools (i.e. children) represents a susceptible population due to their age. Air quality-based studies involving students' exposure at schools are still scarce and often limited to mass-based particle metrics and may thus underestimate the possible effect of sub-micron particles and particle toxicity. To this purpose, the present paper aims to evaluate the exposure to different airborne particle metrics (including both sub- and super-micron particles) and attached carcinogenic compounds. Measurements in terms of particle number, lung-deposited surface area, and PM fraction concentrations were measured inside and outside schools in Barcelona (Spain) and Cassino (Italy). Simultaneously, PM samples were collected and chemically analysed to obtain mass fractions of carcinogenic compounds. School time airborne particle doses received by students in classrooms were evaluated as well as their excess lung cancer risk due to a five-year primary school period. Median surface area dose received by students during school time in Barcelona and Cassino resulted equal to 110mm(2) and 303mm(2), respectively. The risk related to the five-year primary school period was estimated as about 2.9×10(-5) and 1.4×10(-4) for students of Barcelona and Cassino, respectively. The risk in Barcelona is slightly higher with respect to the maximum tolerable value (10(-5), according to the U.S. Environmental Protection Agency), mainly due to toxic compounds on particles generated from anthropogenic emissions (mainly industry). On the other hand, the excess lung cancer risk in Cassino is cause of concern, being one order of magnitude higher than the above-mentioned threshold value due to the presence of biomass burning heating systems and winter thermal inversion that cause larger doses and great amount of toxic compounds on particles.
In the present study, the daily dose in terms of particle surface area received by citizens living in five cities in Western countries, characterized by different lifestyle, culture, climate and built-up environment, was evaluated and compared. For this purpose, the exposure to sub-micron particle concentration levels of the population living in Barcelona (Spain), Cassino (Italy), Guilford (United Kingdom), Lund (Sweden), and Brisbane (Australia) was measured through a direct exposure assessment approach. In particular, measurements of the exposure at a personal scale were performed by volunteers (15 per each population) that used a personal particle counter for different days in order to obtain exposure data in microenvironments/activities they resided/performed. Non-smoking volunteers performing non-industrial jobs were considered in the study. Particle concentration data allowed obtaining the exposure of the population living in each city. Such data were combined in a Monte Carlo method with the time activity pattern data characteristics of each population and inhalation rate to obtain the most probable daily dose in term of particle surface area as a function of the population gender, age, and nationality. The highest daily dose was estimated for citizens living in Cassino and Guilford (>1000 mm(2)), whereas the lowest value was recognized for Lund citizens (around 100 mm(2)). Indoor air quality, and in particular cooking and eating activities, was recognized as the main influencing factor in terms of exposure (and thus dose) of the population: then confirming that lifestyle (e.g. time spent in cooking activities) strongly affect the daily dose of the population. On the contrary, a minor or negligible contribution of the outdoor microenvironments was documented.
Recently, interest for the potential impact of consumer-relevant engineered nanoparticles on pregnancy has dramatically increased. This study investigates whether inhaled silver nanoparticles (AgNPs) reach and cross mouse placental barrier and induce adverse effects. Apart from their relevance for the growing use in consumer products and biomedical applications, AgNPs are selected since they can be unequivocally identified in tissues. Pregnant mouse females are exposed during the first 15 days of gestation by nose-only inhalation to a freshly produced aerosol of 18-20 nm AgNPs for either 1 or 4 hours, at a particle number concentration of 3.80 × 107 part. cm⁻³ and at a mass concentration of 640 µg/m³. AgNPs are identified and quantitated in maternal tissues, placentas and foetuses by Transmission Electron Microscopy coupled with Energy-dispersive X-ray spectroscopy and single-particle Inductively Coupled Plasma Mass Spectrometry. Inhalation of AgNPs results in increased number of resorbed foetuses, associated to reduced oestrogen plasma levels, in the 4h/day exposed mothers. Increased expression of pregnancy-relevant inflammatory cytokines is also detected in the placentas of both groups. These results proof that NPs are able to reach and cross the mouse placenta, and suggest that precaution should be taken with respect to acute exposure to nanoparticles during pregnancy.
Cigarette smoking represents the main cause of lung cancer events. This is due to the carcinogenic compounds condensed onto particles generated during the combustion process and then inhaled through the mainstream side (i.e. the cigarette filter side) of the cigarette. The present paper applied a novel lung cancer risk model, able to take into account both ultrafine and coarse particle toxicity, to the particle concentration levels measured in the mainstream aerosol of cigarettes in order to provide a useful provisional tool for testing different smoking scenarios.
Introduction:
Dysfunction of the autonomic nervous system is one of the postulated pathways linking short-term exposure to air pollution to adverse cardiovascular outcomes. A hypothesis is that exposure to air pollution decreases heart rate variability, a recognized independent predictor of poorer cardiovascular prognosis.
Methods:
We conducted a structured review of panel studies published between 1946 and July 2015 of the association between ambient air pollution and parameters of heart rate variability reflecting autonomic nervous function. We focused on exposure to mass concentrations of fine particles (PM2.5), nitrogen dioxide (NO2), and ozone (O3), and four commonly used indices of heart rate variability (HRV): standard deviation of all normal-to-normal intervals (SDNN); root mean square of successive differences in adjacent normal-to-normal intervals (RMSSD); high frequency power (HF); and low frequency power (LF). We searched bibliographic databases and references of identified articles and abstracted characteristics of their design and conduct, and synthesized the quantitative findings in graphic form according to health condition of the study population and the functional form of the HRV indices used in the regression analyses.
Results:
A total of 33 panel studies were included: 31, 12, and 13 studies were used to investigate ambient exposure to PM2.5, NO2 and O3, respectively. We found substantial variation across studies in terms of design characteristics and statistical methodologies, and we identified some studies that may have had methodological and statistical issues. Because many panel studies were not comparable to each other, meta-analyses were not generally possible, although we were able to pool the results obtained amongst older adults who had cardiovascular disease for the 24-h average concentrations of PM2.5 prior to the heart rate variability measurements. In studies of PM2.5 among older adults with cardiovascular disease, logarithmic transformations of the HRV indices were used in ten studies. Negative associations across all HRV indices were found in 60-86% of these studies for periods of exposures ranging from 5-min to 5-days. The pooled percent changes for an increase of 10μg/m(3) in the 24-h prior to the measurements of HRV were: -2.11% for SDNN (95% confidence interval (95%CI): -4.00, -0.23%), -3.29% for RMSSD (95%CI: -6.32, -0.25%), -4.76% for LF (95%CI: -12.10, 2.58%), and -1.74% for HF (95%CI: -7.79, 4.31%). No transformations were used in seven studies of PM2.5 among older adults with cardiovascular disease, and we found for absolute differences pooled changes in the HRV indices, for an increase of 10μg/m(3), of -0.31ms for SDNN (95%CI: -1.02, 0.41ms) and -1.22ms for RMSSD (95%CI: -2.37; -0.07ms). For gaseous pollutants, negative associations over periods of exposure ranging from 5-min or to 5-days prior to the heart rate variability measurements were reported in 71-83% of studies of NO2 and 57-100% of studies of O3, depending of the indices of heart rate variability. However, many of these studies had statistical or methodological issues, and in the few studies without these issues the confidence intervals were relatively wide and mostly included the null.
Conclusions and discussion:
We were not persuaded by the results that there was an association between PM2.5 and any of the four indices of heart rate variability. For NO2 and O3 the number of high-quality studies was insufficient to draw any definite conclusions. Further panel studies with improved design and methodologies are needed to help establish or refute an association between ambient exposure to air pollution and heart rate variability.
CONTEXT: Short-term fluctuations in air pollution have been associated with changes in both overall and cardiovascular mortality. OBJECTIVE: To consider the effects of air pollution on myocardial infarction (MI) risk by systematically reviewing studies looking at this specific outcome. DATA SOURCES: Medline, Embase and TOXNET publication databases, as well as reference lists and the websites of relevant public organisations. STUDY SELECTION: Studies presenting original data with MI as a specific outcome and one or more of the following as an exposure of interest were included: particulate matter (PM), black carbon/black smoke, ozone, carbon monoxide, nitrogen oxides, sulphur dioxide and traffic exposure. DATA EXTRACTION: The effects of each pollutant on risk of MI, including effect sizes and confidence intervals, were recorded where possible. Methodological details were also extracted including study population, location and setting, ascertainment of MI events, adjustment for potential confounders and consideration of lagged effects. RESULTS: 26 studies were identified: 19 looked at the short-term effects of pollution on a daily timescale; the remaining 7 at longer-term effects. A proportion of studies reported statistically significant detrimental effects of PM with diameter <2.5 microm (3/5 studies, risk increase estimates ranging from 5 to 17% per 10 microg/m(3) increase), PM <10 microm (3/10, 0.7-11% per 10 microg/m(3)), CO (6/14, 2-4% per ppm), SO(2) (6/13, effect estimates on varied scales) and NO(2 )(6/13, 1-9% per 10 ppb). Increasing ozone levels were associated with a reduction in MI risk in 3/12 studies. A number of differences in location, population and demographics and study methodology between studies were identified that might have affected results. CONCLUSION: There is some evidence that short-term fluctuations in air pollution affect the risk of MI. However, further studies are needed to clarify the nature of these effects and identify vulnerable populations and individuals.
Please refer to the fifth edition published in 2025.
This paperback edition is a reprint of the 2000 edition.
This book provides a comprehensive treatment of linear mixed models for continuous longitudinal data. Next to model formulation, this edition puts major emphasis on exploratory data analysis for all aspects of the model, such as the marginal model, subject-specific profiles, and residual covariance structure. Further, model diagnostics and missing data receive extensive treatment. Sensitivity analysis for incomplete data is given a prominent place. Several variations to the conventional linear mixed model are discussed (a heterogeity model, conditional linear mixed models). This book will be of interest to applied statisticians and biomedical researchers in industry, public health organizations, contract research organizations, and academia. The book is explanatory rather than mathematically rigorous. Most analyses were done with the MIXED procedure of the SAS software package, and many of its features are clearly elucidated. However, some other commercially available packages are discussed as well. Great care has been taken in presenting the data analyses in a software-independent fashion.
Geert Verbeke is Professor in Biostatistics at the Biostatistical Centre of the Katholieke Universiteit Leuven in Belgium. He is Past President of the Belgian Region of the International Biometric Society, a Board Member of the American Statistical Association, and past Joint Editor of the Journal of the Royal Statistical Society, Series A (2005--2008). He is the director of the Leuven Center for Biostatistics and statistical Bioinformatics (L-BioStat), and vice-director of the Interuniversity Institute for Biostatistics and statistical Bioinformatics (I-BioStat), a joint initiative of the Hasselt and Leuven universities in Belgium.
Geert Molenberghs is Professor of Biostatistics at Universiteit Hasselt and Katholieke Universiteit Leuven in Belgium. He was Joint Editor of Applied Statistics (2001-2004) and Co-Editor of Biometrics (2007-2009). He was President of the International Biometric Society (2004-2005), and has received the Guy Medal in Bronze from the Royal Statistical Society and the Myrto Lefkopoulou award from the Harvard School of Public Health. He is founding director of the Center for Statistics and also the director of the Interuniversity Institute for Biostatistics and statistical Bioinformatics.
Both authors have received the American Statistical Association's Excellence in Continuing Education Award in 2002, 2004, 2005, and 2008. Both are elected Fellows of the American Statistical Association and elected members of the International Statistical Institute.
Chapter 2 dealt with aspects of modeling such as transformations of predictors, relaxing linearity assumptions, modeling interactions, and examining lack of fit. Chapter 3 dealt with missing data, focusing on utilization of incomplete predictor information. All of these areas are important in the overall scheme of model development, and they cannot be separated from what is to follow. In this chapter we concern ourselves with issues related to the whole model, with emphasis on deciding on the amount of complexity to allow in the model and on dealing with large numbers of predictors. The chapter concludes with three default modeling strategies depending on whether the goal is prediction, estimation, or hypothesis testing.
Many modifications build on Tukey's original box plot. A proposed further adaptation, the violin plot, pools the best statistical features of alternative graphical representations of batches of data. It adds the information available from local density estimates to the basic summary statistics inherent in box plots. This marriage of summary statistics and density shape into a single plot provides a useful tool for data analysis and exploration.
The present work is focused on the characterization of a sub-micrometer aerosol generation system (TSI 3940) in terms of particle number distributions and total concentrations as a function of the solution. Fourteen soluble salts were tested, and different solution molar concentrations were considered. The experimental apparatus was composed of a Submicrometer Aerosol Generator TSI 3940, a Scanning Mobility Particle Sizer spectrometer (SMPS 3936, TSI), and a Condensation Particle Counter (CPC TSI 3775). Particle number distributions and total concentrations were found to change as a function of the molar concentration of the solution. In addition, at a fixed molar concentration of the solution, different particle number distributions and total concentrations were measured as a function of the salt used in the solution preparation. The mode and standard deviation of the distribution also varied as the solution changed, and thus salts able to provide number concentrations higher than the NaCl ones at low diameter ranges were obtained. For example, ammonium chloride (NH 4 Cl) provided particle number concentrations at 8 nm and 10 nm about 40-fold and twice the NaCl ones, respectively.
Few recent studies examined acute effects on health of individual chemical species in the particulate matter (PM) mixture, and most of them have been conducted in North America. Studies in Southern Europe are scarce. The aim of this study is to examine the relationship between particulate matter constituents and daily hospital admissions and mortality in five cities in Southern Europe.
The study included five cities in Southern Europe, three cities in Spain: Barcelona (2003-2010), Madrid (2007-2008) and Huelva (2003-2010); and two cities in Italy: Rome (2005-2007) and Bologna (2011-2013). A case-crossover design was used to link cardiovascular and respiratory hospital admissions and total, cardiovascular and respiratory mortality with a pre-defined list of 16 PM10 and PM2.5 constituents. Lags 0 to 2 were examined. City-specific results were combined by random-effects meta-analysis.
Most of the elements studied, namely EC, SO4(2-), SiO2, Ca, Fe, Zn, Cu, Ti, Mn, V and Ni, showed increased percent changes in cardiovascular and/or respiratory hospitalizations, mainly at lags 0 and 1. The percent increase by one interquartile range (IQR) change ranged from 0.69% to 3.29%. After adjustment for total PM levels, only associations for Mn, Zn and Ni remained significant. For mortality, although positive associations were identified (Fe and Ti for total mortality; EC and Mg for cardiovascular mortality; and NO3(-) for respiratory mortality) the patterns were less clear.
The associations found in this study reflect that several PM constituents, originating from different sources, may drive previously reported results between PM and hospital admissions in the Mediterranean area.
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Epidemiological studies have shown associations between ambient air pollution and changes in heart rate variability (HRV). However, studies using personal air pollution measurements, especially with exposure averages <24h, are still rare. Between February and March 2008 HRV data as well as personal exposure to particulate matter <2.5μm (PM2.5), and particle number concentrations (PNC) were collected in five volunteers for up to 8.3h on a 5min resolution. Information about the participant's whereabouts was also collected. Mixed models were used to analyze concurrent and up to 30min delayed effects of air pollutants as well as being in traffic on 5min-averages of heart rate (HR), high and low frequency power (HF and LF), standard deviation of all normal-to-normal intervals (SDNN), and the root mean square of successive interval differences (RMSSD). Results are presented as %-change from the mean per increase in interquartile range of air pollutant. In total, 474 5-min segments were available for analysis. We observed concurrent and delayed reductions in SDNN of about 0.8-1.0% in association with a 5.4μg/m(3) increase in PM2.5. However, being in traffic by car led to an increase of about 20% 10-14min and 15-19min later. An increase in PM2.5 or PNC was associated with lagged decreases for RMSSD and HF. We detected concurrent reductions in RMSSD (-17.6% [95%-confidence interval: 29.1; -4.3]) when being in traffic by bike/foot. Being in traffic by car was associated with an immediate reduction in LF while more delayed increases in LF were observed when being in traffic by bike/foot. Air pollution and traffic effects on HR were less consistent. These rapid changes in HRV within 30min might be mediated by the autonomic nervous system in response to direct reflexes from receptors in the lungs.
Dependent data arise in many studies. Frequently adopted sampling designs, such as cluster, multilevel, spatial, and repeated measures, may induce this dependence, which the analysis of the data needs to take into due account. In a previous publication (Geraci and Bottai in Biostatistics 8:140–154, 2007), we proposed a conditional quantile regression model for continuous responses where subject-specific random intercepts were included to account for within-subject dependence in the context of longitudinal data analysis. The approach hinged upon the link existing between the minimization of weighted absolute deviations, typically used in quantile regression, and the maximization of a Laplace likelihood. Here, we consider an extension of those models to more complex dependence structures in the data, which are modeled by including multiple random effects in the linear conditional quantile functions. We also discuss estimation strategies to reduce the computational burden and inefficiency associated with the Monte Carlo EM algorithm we have proposed previously. In particular, the estimation of the fixed regression coefficients and of the random effects’ covariance matrix is based on a combination of Gaussian quadrature approximations and non-smooth optimization algorithms. Finally, a simulation study and a number of applications of our models are presented.
Exposure to ultrafine particles (UFPs) is deemed to be a major risk affecting human health. Therefore, airborne particle studies were performed in the recent years to evaluate the most critical micro-environments, as well as identifying the main UFP sources.Nonetheless, in order to properly evaluate the UFP exposure, personal monitoring is required as the only way to relate particle exposure levels to the activities performed and micro-environments visited.To this purpose, in the present work, the results of experimental analysis aimed at showing the effect of the time-activity patterns on UFP personal exposure are reported. In particular, 24 non-smoking couples (12 during winter and summer time, respectively), comprised of a man who worked full-time and a woman who was a homemaker, were analyzed using personal particle counter and GPS monitors. Each couple was investigated for a 48-h period, during which they also filled out a diary reporting the daily activities performed. Time activity patterns, particle number concentration exposure and the related dose received by the participants, in terms of particle alveolar-deposited surface area, were measured.The average exposure to particle number concentration was higher for women during both summer and winter (Summer: women 1.8×104 part. cm-3; men 9.2×103 part. cm-3; Winter: women 2.9×104 part. cm-3; men 1.3×104 part. cm-3), which was likely due to the time spent undertaking cooking activities. Staying indoors after cooking also led to higher alveolar-deposited surface area dose for both women and men during the winter time (9.12×102 and 6.33×102mm2, respectively), when indoor ventilation was greatly reduced. The effect of cooking activities was also detected in terms of women's dose intensity (dose per unit time), being 8.6 and 6.6 in winter and summer, respectively. On the contrary, the highest dose intensity activity for men was time spent using transportation (2.8 in both winter and summer).
Many modifications build on Tukey's original box plot. A proposed further adaptation, the violin plot, pools the best statistical features of alternative graphical representations of batches of data. It adds the information available from local density estimates to the basic summary statistics inherent in box plots. This marriage of summary statistics and density shape into a single plot provides a useful tool for data analysis and exploration.
Air pollution is a widespread health problem associated with respiratory symptoms. Continuous exposure monitoring was performed to estimate alveolar and tracheobronchial dose, measured as deposited surface area, for 103 children and to evaluate the long-term effects of exposure to airborne particles through spirometry, skin prick tests and measurement of exhaled nitric oxide (eNO). The mean daily alveolar deposited surface area dose received by children was 1.35 × 10(3) mm(2). The lowest and highest particle number concentrations were found during sleeping and eating time. A significant negative association was found between changes in pulmonary function tests and individual dose estimates. Significant differences were found for asthmatics, children with allergic rhinitis and sensitive to allergens compared to healthy subjects for eNO. Variation is a child's activity over time appeared to have a strong impact on respiratory outcomes, which indicates that personal monitoring is vital for assessing the expected health effects of exposure to particles.
Exposure to particle concentrations in urban areas was evaluated in several studies since airborne particles are considered to bring about adverse health effects. Transportation modes and urban microenvironments account for the highest contributions to the overall daily particle exposure concentration.In the present study an evaluation of the influential parameters affecting particle exposure of pedestrian in urban areas is reported. Street geometry, traffic mode, wind speed and direction effects were analyzed through an experimental campaign performed in different streets of an Italian town. To this purpose a high-resolution time measurement apparatus was used in order to capture the dynamic of the freshly emitted particles.Number, surface area and mass concentrations and distributions were measured continuously along both the sides of street canyons and avenue canyons during 10-minutes walking routes. The combined effect of street geometry and wind direction may contribute strongly to dilute the fresh particles emitted by vehicles. In particular, street canyons are characterized by lower ventilation phenomena which lead to similar concentration values on both the side of the street. Higher wind speed was found to decrease concentrations in the canyon. Traffic mode also seems to influence exposure concentrations. In particular, submicrometer particle mass concentration was higher as the traffic is more congested; otherwise, coarse fraction dominates mass exposure concentration along street characterized by a more fluent traffic, showing a typical resuspension modality.
Exposure to ultrafine particles (diameter less than 100 nm) is an important topic in epidemiological and toxicological studies. This study used the average particle number size distribution data obtained from our measurement survey in major microenvironments, together with the people activity pattern data obtained from the Italian Human Activity Pattern Survey to estimate the tracheobronchial and alveolar dose of submicrometer particles for different population age groups in Italy. We developed a numerical methodology based on Monte Carlo method, in order to estimate the best combination from a probabilistic point of view. More than 106 different cases were analyzed according to a purpose built sub-routine and our results showed that the daily alveolar particle number and surface area deposited for all of the age groups considered was equal to 1.5 × 1011 particles and 2.5 × 1015 μm2, respectively, varying slightly for males and females living in Northern or Southern Italy. In terms of tracheobronchial deposition, the corresponding values for daily particle number and surface area for all age groups was equal to 6.5 × 1010 particles and 9.9 × 1014 μm2, respectively. Overall, the highest contributions were found to come from indoor cooking (female), working time (male) and transportation (i.e. traffic derived particles) (children).Highlights► We estimate particle number and surface area deposition for different age groups and lifestyles through an indirect approach. ► Particle number distribution range for each microenvironment was obtained from our measurement survey data. ► Deposition increases as a function age group, with the maximum value observed for 41–65 years old. ► Major contributions arise from indoor cooking and eating times (female), working time (male) and transportation (children).
Exposure to air pollution is associated with adverse effects on health. In particular, a strong epidemiologic association is observed between acute and chronic exposures to particulate matter and the occurrence of cardiovascular events, coronary artery disease, cerebrovascular disease and venous thromboembolism, especially among older people and people with diabetes and previous cardiovascular conditions. Multiple mechanisms have been postulated to cause the increase in atherothrombotic and thromboembolic events, including the activation by particulate matter of inflammatory pathways and hemostasis factors, production of reactive oxygen species through the oxidative stress pathway, alterations in vascular tone, and decreased heart rate variability (a marker of cardiac autonomic dysfunction and a predictor of sudden cardiac death and arrhythmias). Current knowledge on the biologic mechanisms and the clinical effect of short- and long-term exposure to particulate air pollutants is discussed, emphasizing that life expectancy improved significantly in sites where air pollutants were controlled.
In 2004, the first American Heart Association scientific statement on "Air Pollution and Cardiovascular Disease" concluded that exposure to particulate matter (PM) air pollution contributes to cardiovascular morbidity and mortality. In the interim, numerous studies have expanded our understanding of this association and further elucidated the physiological and molecular mechanisms involved. The main objective of this updated American Heart Association scientific statement is to provide a comprehensive review of the new evidence linking PM exposure with cardiovascular disease, with a specific focus on highlighting the clinical implications for researchers and healthcare providers. The writing group also sought to provide expert consensus opinions on many aspects of the current state of science and updated suggestions for areas of future research. On the basis of the findings of this review, several new conclusions were reached, including the following: Exposure to PM <2.5 microm in diameter (PM(2.5)) over a few hours to weeks can trigger cardiovascular disease-related mortality and nonfatal events; longer-term exposure (eg, a few years) increases the risk for cardiovascular mortality to an even greater extent than exposures over a few days and reduces life expectancy within more highly exposed segments of the population by several months to a few years; reductions in PM levels are associated with decreases in cardiovascular mortality within a time frame as short as a few years; and many credible pathological mechanisms have been elucidated that lend biological plausibility to these findings. It is the opinion of the writing group that the overall evidence is consistent with a causal relationship between PM(2.5) exposure and cardiovascular morbidity and mortality. This body of evidence has grown and been strengthened substantially since the first American Heart Association scientific statement was published. Finally, PM(2.5) exposure is deemed a modifiable factor that contributes to cardiovascular morbidity and mortality.
We conducted a systematic review of all studies published between 1950 and 2007 of associations between long-term exposure to ambient air pollution and the risks in adults of nonaccidental mortality and the incidence and mortality from cancer and cardiovascular and respiratory diseases. We searched bibliographic databases for cohort and case-control studies, abstracted characteristics of their design and conduct, and synthesized the quantitative findings in tabular and graphic form. We assessed heterogeneity, estimated pooled effects for specific pollutants, and conducted sensitivity analyses according to selected characteristics of the studies. Our analysis showed that long-term exposure to PM2.5 increases the risk of nonaccidental mortality by 6% per a 10 microg/m3 increase, independent of age, gender, and geographic region. Exposure to PM2.5 was also associated with an increased risk of mortality from lung cancer (range: 15% to 21% per a 10 microg/m3 increase) and total cardiovascular mortality (range: 12% to 14% per a 10 microg/m3 increase). In addition, living close to busy traffic appears to be associated with elevated risks of these three outcomes. Suggestive evidence was found that exposure to PM2.5 is positively associated with mortality from coronary heart diseases and exposure to SO2 increases mortality from lung cancer. For the other pollutants and health outcomes, the data were insufficient data to make solid conclusions.
Exposure to ambient ultrafine particles has been associated with cardiopulmonary toxicity and mortality. Adverse effects specifically linked to ultrafine particles include loss of sympathovagal balance and altered hemostasis.
To characterize the effects of acute exposure to ambient ultrafine particles in young healthy humans.
Nineteen healthy nonsmoking male and female subjects between the ages of 18 and 35 were exposed to filtered air or to an atmosphere in which captured ultrafine (<0.16 microm) particles were concentrated by a factor of up to 20-fold over ambient levels with the use of particle concentrators fitted with size-selective outlets (ultrafine concentrated ambient particles [UFCAPs]). Subjects underwent bronchoalveolar lavage 18 hours after each exposure. Cardiovascular endpoints measured included pulmonary function, clinical chemistry, and hematological parameters, as well as heart rate variability and repolarization indices.
Exposure to UFCAPs was statistically associated with an increase in frequency domain markers of heart rate variability, specifically indicative of elevated vagal input to the heart. Consistent with this finding were increases in the variance associated with the duration of the QT interval. In addition, UFCAP exposure resulted in a significant increase in blood levels of the fibrin degradation product D-dimer as well as a modest elevation in the inflammatory chemokine IL-8 recovered in the lavage fluid.
These findings show mild inflammatory and prothrombic responses and are suggestive of alterations in cardiac repolarization induced by UFCAP inhalation.
The mechanisms underlying the association between air pollution and cardiovascular morbidity and mortality are unknown. This study aimed to determine whether controlled exposure to elemental carbon ultrafine particles (UFP) affects electrocardiogram (ECG) parameters describing heart rate variability; repolarization duration, morphology, and variability; and changes in the ST segment. Two separate controlled studies (12 subjects each) were performed using a crossover design, in which each subject was exposed to filtered air and carbon UFP for 2 hours. The first protocol involved 2 exposures to air and 10 microg/m(3) (approximately 2 x 10(6) particles/cm(3), count median diameter approximately 25 nm, geometric standard deviation approximately 1.6), at rest. The second protocol included 3 exposures to air, 10, and 25 microg/m(3) UFP (approximately 7 x 10(6) particles/cm(3)), with repeated exercise. Each subject underwent a continuous digital 12-lead ECG Holter recording to analyze the above ECG parameters. Repeated measures analysis of variance (ANOVA) was used to compare tested parameters between exposures. The observed responses to UFP exposure were small and generally not significant, although there were trends indicating an increase in parasympathetic tone, which is most likely also responsible for trends toward ST elevation, blunted QTc shortening, and increased variability of T-wave complexity after exposure to UFP. Recovery from exercise showed a blunted response of the parasympathetic system after exposure to UFP in comparison to air exposure. In conclusion, transient exposure to 10-25 microg/m(3) ultrafine carbon particles does not cause marked changes in ECG-derived parameters in young healthy subjects. However, trends are observed indicating that some subjects might be susceptible to air pollution, with a response involving autonomic modulation of the heart and repolarization of the ventricular myocardium.
Air pollution is a heterogeneous mixture of gases, liquids and PM (particulate matter). In the modern urban world, PM is principally derived from fossil fuel combustion with individual constituents varying in size from a few nanometres to 10 microm in diameter. In addition to the ambient concentration, the pollution source and chemical composition may play roles in determining the biological toxicity and subsequent health effects. Nevertheless, studies from across the world have consistently shown that both short- and long-term exposures to PM are associated with a host of cardiovascular diseases, including myocardial ischaemia and infarctions, heart failure, arrhythmias, strokes and increased cardiovascular mortality. Evidence from cellular/toxicological experiments, controlled animal and human exposures and human panel studies have demonstrated several mechanisms by which particle exposure may both trigger acute events as well as prompt the chronic development of cardiovascular diseases. PM inhaled into the pulmonary tree may instigate remote cardiovascular health effects via three general pathways: instigation of systemic inflammation and/or oxidative stress, alterations in autonomic balance, and potentially by direct actions upon the vasculature of particle constituents capable of reaching the systemic circulation. In turn, these responses have been shown to trigger acute arterial vasoconstriction, endothelial dysfunction, arrhythmias and pro-coagulant/thrombotic actions. Finally, long-term exposure has been shown to enhance the chronic genesis of atherosclerosis. Although the risk to one individual at any single time point is small, given the prodigious number of people continuously exposed, PM air pollution imparts a tremendous burden to the global public health, ranking it as the 13th leading cause of morality (approx. 800,000 annual deaths).
: Exposure to airborne particles may increase cardiac risk by altering autonomic balance. Because these risks may be particularly great for traffic-related particles, we examined associations between particles and heart rate variability as 44 subjects participated in 4 repeated trips aboard a diesel bus.
: Twenty-four hour electrocardiograms were correlated with continuous particle concentrations using generalized additive models controlling for subject, weekday, time, apparent temperature, trip type, activity, medications, and autoregressive terms. Associations were assessed for short- and medium-term moving averages of measured concentrations.
: Heart rate variability was negatively associated with fine particulate matter. Positive associations were demonstrated with heart rate and the low-to-high frequency power ratio. Associations were strongest with 24-hour mean concentrations, although strong short-term associations also were found during bus periods, independent of daily exposures. Overall, associations were greatest for high-frequency power with the following effects per interquartile change in the 24-hour mean concentrations: -15% (95% confidence interval = -17% to -14%) for PM2.5 (4.6 mug/m); -19% (-21% to -17%) for black carbon (459 ng/m); and -14% (-15% to -12%) for fine particle counts (39 pt/cm). For each interquartile change in the 5-minute PM2.5 concentration (10 mug/m) aboard the bus, an 11% (95% confidence interval = -14% to -8%) decrease in high-frequency power was observed.
: This investigation indicates that fine particles are negatively associated with heart rate variability, with an overall trend towards reduced parasympathetic tone. Although daily associations were evident for all particles, short-term associations were predominantly limited to traffic-related particles.
Particulate matter air pollution has been related to an increase in cardiopulmonary morbidity and mortality especially in susceptible subjects with a known cardiopulmonary disease. Recent studies suggest that PM(2.5) air pollution was associated with changes in heart rate variability (HRV). The purpose of this study was to identify and compare changes in HRV in positive or negative head-up tilt (HUT) participants. Fifty two subjects, 31 women and 21 men, 20-40 years old, underwent PM(2.5) personal monitoring and Holter-ECG monitoring in supine and orthostatic position, during active standing, in indoor and outdoor environments. All measurements were made between 8 and 11 AM in the same geographical location (southeast of Mexico City). Frequency domain indexes were estimated in absolute (ms(2)) and in normalized units (nu) (low frequencies (LF), high frequencies (HF) and low/high frequency ratio (LF/HF)) in 5 min periods by standard methods. Data were transformed into natural logarithmic scale (ln). Comparisons were made between genders and positive and negative HUT subjects. LF were larger and HF were smaller in negative HUT males. Multivariate analysis with GEE models, adjusted for each index, showed a significant decrease of HRV (LFln -0.194 95% CI, -0.4509, 0.0627, and HFln -0.298 95% CI, -0.5553, -0.0401) associated to an increase in PM(2.5) air pollution in positive and negative HUT subjects which was larger for HFln in outdoor environments. PM(2.5) air pollution was associated with changes in HRV in positive and negative HUT subjects without cardiopulmonary disease.
- X Basagaña
- B Jacquemin
- A Karanasiou
- B Ostro
- X Querol
- D Agis
- E Alessandrini
- J Alguacil
- B Artiñano
- M Catrambone
- J D De La Rosa
- J Díaz
- A Faustini
- S Ferrari
- F Forastiere
- K Katsouyanni
- C Linares
- C Perrino
- A Ranzi
- I Ricciardelli
- E Samoli
- S Zauli-Sajani
- J Sunyer
- M Stafoggia
- P Angelini
- G Berti
- L Bisanti
- E Cadum
- M Chiusolo
- M Davoli
- F De'donato
- M Demaria
- M Gandini
- M Grosa
- P Pandolfi
- R Pelosini
- A Pietrodangelo
- L Pizzi
- V Poluzzi
- G Priod
- G Randi
- M Rowinski
- C Scarinzi
- E Stivanello
- K Dimakopoulou
- K Elefteriadis
- A Kelessis
- T Maggos
- N Michalopoulos
- S Pateraki
- M Petrakakis
- S Rodopoulou
- V Sypsa
- J Barrera-Gómez
- J De La Rosa
- J Diaz
- R Fernandez
- N Perez
- J Pey
- P Salvador
- A M Sanchez
- A Tobias
- M Bidondo
- C Declercq
- A Le Tertre
- P Lozano
- S Medina
- L Pascal
- M Pascal
Basagaña, X., Jacquemin, B., Karanasiou, A., Ostro, B., Querol, X., Agis, D., Alessandrini, E.,
Alguacil, J., Artiñano, B., Catrambone, M., De La Rosa, J.D., Díaz, J., Faustini, A., Ferrari, S.,
Forastiere, F., Katsouyanni, K., Linares, C., Perrino, C., Ranzi, A., Ricciardelli, I., Samoli, E.,
Zauli-Sajani, S., Sunyer, J., Stafoggia, M., Angelini, P., Berti, G., Bisanti, L., Cadum, E.,
Chiusolo, M., Davoli, M., De'Donato, F., Demaria, M., Gandini, M., Grosa, M., Pandolfi, P.,
Pelosini, R., Pietrodangelo, A., Pizzi, L., Poluzzi, V., Priod, G., Randi, G., Rowinski, M.,
Scarinzi, C., Stivanello, E., Dimakopoulou, K., Elefteriadis, K., Kelessis, A., Maggos, T.,
Michalopoulos, N., Pateraki, S., Petrakakis, M., Rodopoulou, S., Sypsa, V., Barrera-Gómez,
J., De La Rosa, J., Diaz, J., Fernandez, R., Perez, N., Pey, J., Salvador, P., Sanchez, A.M.,
Tobias, A., Bidondo, M., Declercq, C., Le Tertre, A., Lozano, P., Medina, S., Pascal, L.,
Pascal, M., 2015. Short-term effects of particulate matter constituents on daily hospitalizations and mortality in five South-European cities: results from the MED-PARTICLES
project. Environ. Int. 75, 151-158.
Air pollution and cardiovascular injury
- Simkhovich
Simkhovich, B.Z., Kleinman, M.T., Kloner, R.A., 2008. Air pollution and cardiovascular injury. J. Am. Coll. Cardiol. 52, 719.