Article

Meta-analysis of the effects of indoor nitrogen dioxide and gas cooking on asthma and wheeze in children

August 2013
International Journal of Epidemiology 42(6)

Source
PubMed

Authors:

Utrecht University

Since the meta-analysis on the association between indoor nitrogen dioxide (NO2) and childhood respiratory illness in 1992, many new studies have been published. The quantitative effects of indoor NO2 on respiratory illness have not been estimated in a formal meta-analysis since then. We aimed to quantify the association of indoor NO2 and its main source (gas cooking) with childhood asthma and wheeze. We extracted the association between indoor NO2 (and gas cooking) and childhood asthma and wheeze from population studies published up to 31 March 2013. Data were analysed by inverse-variance-weighted, random-effects meta-analysis. Sensitivity analyses were conducted for different strata. Publication bias and heterogeneity between studies were investigated. A total of 41 studies met the inclusion criteria. The summary odds ratio from random effects meta-analysis for asthma and gas cooking exposure was 1.32 [95% confidential interval (CI) 1.18-1.48], and for a 15-ppb increase in NO2 it was 1.09 (95% CI 0.91-1.31). Indoor NO2 was associated with current wheeze (random effects OR 1.15; 95% CI 1.06-1.25). The estimates did not vary much with age or between regions. There was no evidence of publication bias. This meta-analysis provides quantitative evidence that, in children, gas cooking increases the risk of asthma and indoor NO2 increases the risk of current wheeze.

Reliability of Meta-Analysis Research Claims for Gas Stove Cooking−Childhood Respiratory Health Associations

Article

Full-text available

May 2023

Odds ratios or p-values from individual observational studies can be combined to examine a common cause−effect research question in meta-analysis. However, reliability of individual studies used in meta-analysis should not be taken for granted as claimed cause−effect associations may not reproduce. An evaluation was undertaken on meta-analysis of base papers examining gas stove cooking (including nitrogen dioxide, NO2) and childhood asthma and wheeze associations. Numbers of hypotheses tested in 14 of 27 base papers (52%) used in meta-analysis of asthma and wheeze were counted. Test statistics used in the meta-analysis (40 odds ratios with 95% confidence limits) were converted to p-values and presented in p-value plots. The median (interquartile range) of possible numbers of hypotheses tested in the 14 base papers was 15,360 (6,336−49,152). None of the 14 base papers made mention of correcting for multiple testing, nor was any explanation offered if no multiple testing procedure was used. Given large numbers of hypotheses available, statistics drawn from base papers and used for meta-analysis are likely biased. Even so, p-value plots for gas stove−current asthma and gas stove−current wheeze associations show randomness consistent with unproven gas stove harms. The meta-analysis fails to provide reliable evidence for public health policy making on gas stove harms to children in North America. NO2 is not established as a biologically plausible explanation of a causal link with childhood asthma. Biases – multiple testing and p-hacking – cannot be ruled out as explanation for a gas stove−current asthma association claim. Selective reporting is another bias in published literature of gas stove–childhood respiratory health studies.

Gas cooking and respiratory outcomes in children: A systematic review

Article

Full-text available

Apr 2023

The most recent meta-analysis of gas cooking and respiratory outcomes in children was conducted by Lin et al. [93] in 2013. Since then, a number of epidemiology studies have been published on this topic. We conducted the first systematic review of this epidemiology literature that includes an in-depth evaluation of study heterogeneity and study quality, neither of which was systematically evaluated in earlier reviews. We reviewed a total of 66 relevant studies, including those in the Lin et al. [93] meta-analysis. Most of the studies are cross-sectional by design, precluding causal inference. Only a few are cohort studies that could establish temporality and they have largely reported null results. There is large variability across studies in terms of study region, age of children, gas cooking exposure definition, and asthma or wheeze outcome definition, precluding clear interpretations of meta-analysis estimates such as those reported in Lin et al. [93]. Further, our systematic study quality evaluation reveals that a large proportion of the studies to date are subject to multiple sources of bias and inaccuracy, primarily due to self-reported gas cooking exposure or respiratory outcomes, insufficient adjustment for key confounders (e.g., environmental tobacco smoke, family history of asthma or allergies, socioeconomic status or home environment), and unestablished temporality. We conclude that the epidemiology literature is limited by high heterogeneity and low study quality and, therefore, it does not provide sufficient evidence regarding causal relationships between gas cooking or indoor NO2 and asthma or wheeze. We caution against over-interpreting the quantitative evidence synthesis estimates from meta-analyses of these studies.

Statistical reliability of meta_analysis research claims for gas stove cooking_childhood respiratory health associations

Preprint

Full-text available

Mar 2023

Odds ratios or p_values from individual observational studies can be combined to examine a common cause_effect research question in meta_analysis. However, reliability of individual studies used in meta_analysis should not be taken for granted as claimed cause_effect associations may not reproduce. An evaluation was undertaken on meta_analysis of base papers examining gas stove cooking, including nitrogen dioxide, NO2, and childhood asthma and wheeze associations. Numbers of hypotheses tested in 14 of 27 base papers, 52 percent, used in meta_analysis of asthma and wheeze were counted. Test statistics used in the meta_analysis, 40 odds ratios with 95 percent confidence limits, were converted to p_values and presented in p_value plots. The median and interquartile range of possible numbers of hypotheses tested in the 14 base papers was 15,360, 6,336_49,152. None of the 14 base papers made mention of correcting for multiple testing, nor was any explanation offered if no multiple testing procedure was used. Given large numbers of hypotheses available, statistics drawn from base papers and used for meta-analysis are likely biased. Even so, p-value plots for gas stove_current asthma and gas stove_current wheeze associations show randomness consistent with unproven gas stove harms. The meta-analysis fails to provide reliable evidence for public health policy making on gas stove harms to children in North America. NO2 is not established as a biologically plausible explanation of a causal link with childhood asthma. Biases_multiple testing and p-hacking_cannot be ruled out as explanations for a gas stove_current asthma association claim. Selective reporting is another bias in published literature of gas stove_childhood respiratory health studies. Keywords gas stove, asthma, meta-analysis, p-value plot, multiple testing, p_hacking

Population Attributable Fraction of Gas Stoves and Childhood Asthma in the United States

Article

Full-text available

Dec 2022
Int J Environ Res Publ Health

Indoor gas stove use for cooking is associated with an increased risk of current asthma among children and is prevalent in 35% of households in the United States (US). The population-level implications of gas cooking are largely unrecognized. We quantified the population attributable fraction (PAF) for gas stove use and current childhood asthma in the US. Effect sizes previously reported by meta-analyses for current asthma (Odds Ratio = 1.34, 95% Confidence Interval (CI) = 1.12–1.57) were utilized in the PAF estimations. The proportion of children (<18 years old) exposed to gas stoves was obtained from the American Housing Survey for the US, and states with available data (n = 9). We found that 12.7% (95% CI = 6.3–19.3%) of current childhood asthma in the US is attributable to gas stove use. The proportion of childhood asthma that could be theoretically prevented if gas stove use was not present (e.g., state-specific PAFs) varied by state (Illinois = 21.1%; California = 20.1%; New York = 18.8%; Massachusetts = 15.4%; Pennsylvania = 13.5%). Our results quantify the US public health burden attributed to gas stove use and childhood asthma. Further research is needed to quantify the burden experienced at the county levels, as well as the impacts of implementing mitigation strategies through intervention studies.

Evaluating equity and justice in low-carbon energy transitions

Article

Full-text available

Nov 2023
ENVIRON RES LETT

A low-carbon energy transition is essential for mitigating climate change but can also cause energy justice and equity impacts on Black, Indigenous, and People of Color (BIPOC), low-income, and other frontline communities. Examples include exacerbating energy burden, inaccessibility and unaffordability of low-carbon energy and electric end-use technologies, property value loss and displacement from renewable energy siting, and unequal health benefits and employment losses from fossil fuel retirement. To avoid perpetuating historical and creating new injustices, an equitable and just energy transition will require careful planning and execution. To this end, measuring and evaluating the effects of existing and proposed programs and policies aimed at decarbonizing energy systems is critical. However, methods and metrics for evaluating equity effects vary across disciplines and transitions, making it challenging to identify effective evaluation strategies. This paper presents a comprehensive review of the equity implications of low-carbon energy transitions and identifies key metrics that have been used across disciplines to quantify energy injustices and equity impacts. We focus on four key low-carbon energy transitions: (1) renewable energy deployment; (2) fossil fuel infrastructure retirement; (3) transportation electrification; and (4) residential building decarbonization. We classify energy justice and equity metrics into the dimensions of Health, Access, and Livelihood, and construct an analytical framework that supports policymakers, planners and other stakeholders in identifying important equity considerations and quantitatively evaluating the effects of decarbonization initiatives. While our framework can serve as a starting point for evaluating justice and equity impacts of energy transitions, further work is needed to address the limitations of existing metrics and additional evaluation methods will be critical to effect energy transitions that are truly equitable.

Climate and health benefits of a transition from gas to electric cooking

Article

Aug 2023
P NATL ACAD SCI USA

Household electrification is thought to be an important part of a carbon-neutral future and could also have additional benefits to adopting households such as improved air quality. However, the effectiveness of specific electrification policies in reducing total emissions and boosting household livelihoods remains a crucial open question in both developed and developing countries. We investigated a transition of more than 750,000 households from gas to electric cookstoves-one of the most popular residential electrification strategies-in Ecuador following a program that promoted induction stoves and assessed its impacts on electricity consumption, greenhouse gas emissions, and health. We estimate that the program resulted in a 5% increase in total residential electricity consumption between 2015 and 2021. By offsetting a commensurate amount of cooking gas combustion, we find that the program likely reduced national greenhouse gas emissions, thanks in part to the country's electricity grid being 80% hydropower in later parts of the time period. Increased induction stove uptake was also associated with declines in all-cause and respiratory-related hospitalizations nationwide. These findings suggest that, when the electricity grid is largely powered by renewables, gas-to-induction cooking transitions represent a promising way of amplifying the health and climate cobenefits of net-carbon-zero policies.

Gas and Propane Combustion from Stoves Emits Benzene and Increases Indoor Air Pollution

Article

Full-text available

Jun 2023

Exposure pathways to the carcinogen benzene are well-established from tobacco smoke, oil and gas development, refining, gasoline pumping, and gasoline and diesel combustion. Combustion has also been linked to the formation of nitrogen dioxide, carbon monoxide, and formaldehyde indoors from gas stoves. To our knowledge, however, no research has quantified the formation of benzene indoors from gas combustion by stoves. Across 87 homes in California and Colorado, natural gas and propane combustion emitted detectable and repeatable levels of benzene that in some homes raised indoor benzene concentrations above well-established health benchmarks. Mean benzene emissions from gas and propane burners on high and ovens set to 350 °F ranged from 2.8 to 6.5 μg min-1, 10 to 25 times higher than emissions from electric coil and radiant alternatives; neither induction stoves nor the food being cooked emitted detectable benzene. Benzene produced by gas and propane stoves also migrated throughout homes, in some cases elevating bedroom benzene concentrations above chronic health benchmarks for hours after the stove was turned off. Combustion of gas and propane from stoves may be a substantial benzene exposure pathway and can reduce indoor air quality.

Adverse health effects associated with household air pollution: a systematic review, meta-analysis, and burden estimation study

Article

Full-text available

Nov 2020

Background 3 billion people worldwide rely on polluting fuels and technologies for domestic cooking and heating. We estimate the global, regional, and national health burden associated with exposure to household air pollution. Methods For the systematic review and meta-analysis, we systematically searched four databases for studies published from database inception to April 2, 2020, that evaluated the risk of adverse cardiorespiratory, paediatric, and maternal outcomes from exposure to household air pollution, compared with no exposure. We used a random-effects model to calculate disease-specific relative risk (RR) meta-estimates. Household air pollution exposure was defined as use of polluting fuels (coal, wood, charcoal, agricultural wastes, animal dung, or kerosene) for household cooking or heating. Temporal trends in mortality and disease burden associated with household air pollution, as measured by disability-adjusted life-years (DALYs), were estimated from 2000 to 2017 using exposure prevalence data from 183 of 193 UN member states. 95% CIs were estimated by propagating uncertainty from the RR meta-estimates, prevalence of household air pollution exposure, and disease-specific mortality and burden estimates using a simulation-based approach. This study is registered with PROSPERO, CRD42019125060. Findings 476 studies (15·5 million participants) from 123 nations (99 [80%] of which were classified as low-income and middle-income) met the inclusion criteria. Household air pollution was positively associated with asthma (RR 1·23, 95% CI 1·11–1·36), acute respiratory infection in both adults (1·53, 1·22–1·93) and children (1·39, 1·29–1·49), chronic obstructive pulmonary disease (1·70, 1·47–1·97), lung cancer (1·69, 1·44–1·98), and tuberculosis (1·26, 1·08–1·48); cerebrovascular disease (1·09, 1·04–1·14) and ischaemic heart disease (1·10, 1·09–1·11); and low birthweight (1·36, 1·19–1·55) and stillbirth (1·22, 1·06–1·41); as well as with under-5 (1·25, 1·18–1·33), respiratory (1·19, 1·18–1·20), and cardiovascular (1·07, 1·04–1·11) mortality. Household air pollution was associated with 1·8 million (95% CI 1·1–2·7) deaths and 60·9 million (34·6–93·3) DALYs in 2017, with the burden overwhelmingly experienced in low-income and middle-income countries (LMICs; 60·8 million [34·6–92·9] DALYs) compared with high-income countries (0·09 million [0·01–0·40] DALYs). From 2000, mortality associated with household air pollution had reduced by 36% (95% CI 29–43) and disease burden by 30% (25–36), with the greatest reductions observed in higher-income nations. Interpretation The burden of cardiorespiratory, paediatric, and maternal diseases associated with household air pollution has declined worldwide but remains high in the world's poorest regions. Urgent integrated health and energy strategies are needed to reduce the adverse health impact of household air pollution, especially in LMICs. Funding British Heart Foundation, Wellcome Trust.

Cooking Emissions

Technical Report

Full-text available

May 2019

Impact of Air Pollution on Asthma Outcomes

Article

Full-text available

Aug 2020
Int J Environ Res Publ Health

Asthma is a chronic respiratory disease characterized by variable airflow obstruction, bronchial hyperresponsiveness, and airway inflammation. Evidence suggests that air pollution has a negative impact on asthma outcomes in both adult and pediatric populations. The aim of this review is to summarize the current knowledge on the effect of various outdoor and indoor pollutants on asthma outcomes, their burden on its management, as well as to highlight the measures that could result in improved asthma outcomes. Traffic-related air pollution, nitrogen dioxide and second-hand smoking (SHS) exposures represent significant risk factors for asthma development in children. Nevertheless, a causal relation between air pollution and development of adult asthma is not clearly established. Exposure to outdoor pollutants can induce asthma symptoms, exacerbations and decreases in lung function. Active tobacco smoking is associated with poorer asthma control, while exposure to SHS increases the risk of asthma exacerbations, respiratory symptoms and healthcare utilization. Other indoor pollutants such as heating sources and molds can also negatively impact the course of asthma. Global measures, that aim to reduce exposure to air pollutants, are highly needed in order to improve the outcomes and management of adult and pediatric asthma in addition to the existing guidelines.

Impact of Grilling Meat or Fish at Home on Peak Expiratory Flow Rate in Adults With Asthma

Article

Full-text available

Jul 2020

Grilling, a common cooking method worldwide, can produce more toxic gases than other cooking methods. However, the impact of frequently grilling meat or fish at home on airflow limitation in adult asthma has not been well elucidated. We performed a prospective cohort study of 91 adult patients with asthma enrolled from 2 university hospitals. Of the patients, 39 (42.9%) grilled meat or fish at least once a week and 52 (57.1%) less than once a week. Patients who grilled at least once a week tended to have lower peak expiratory flow rate (PEFR) than those who grilled less than once a week (median, 345.5 L/min; 95% confidence interval [CI], 291.8-423.2 L/min vs. median, 375.1 L/min; 95% CI, 319.7-485.7 L/min; P = 0.059). Among patients with severe asthma who received step 4-5 treatment, PEFR was significantly lower in patients who grilled at least once a week compared with those who grilled less than once a week (median, 297.8 L/min; 95% CI, 211.3-357.7 L/min vs. median, 396.1 L/min; 95% CI, 355.0-489.6 L/min; P < 0.001). Our results suggest that the frequency of grilling meat or fish at home may affect PEFR in asthmatic patients, especially those with severe asthma who needed a high level of asthma treatment.

Indoor air pollution and respiratory health effects in inner city children with moderate to severe asthma

Article

Full-text available

Feb 2020

Indoor air pollution is increasingly recognized as a significant risk for respiratory illness, particularly in vulnerable populations. Thirty-six children aged 6–14 years with moderate/severe asthma from inner city areas in New York City were studied for 2-week periods (summer and winter) using diaries and spirometry. Seven-day integrated indoor samples of PM10, PM2.5, trace elements, elemental/organic carbon, black carbon, and criteria gases (NO2, SO2, and O3) were collected in the subjects’ residences. Asthma outcomes included cough and wheeze severity, albuterol use, and pulmonary function. Mixed effects regression models for longitudinal data were used to relate weekly indoor pollutant concentrations to asthma outcomes. Odds ratios (ORs) were calculated for ordinal outcomes. During winter, significant positive associations for average weekly symptom severity scores were seen for NO2 (OR = 2.83; p = 0.02), calcium (OR = 3.29; p = 0.02), and silicon (OR = 3.64; p = 0.04). In summer, chlorine was associated with average weekly symptom scores (OR = 1.85; p = 0.004). Average albuterol puff use per day in winter was associated with NO2 (OR = 5.89; p = 0.009), nickel (OR = 2.27; p = 0.05), and silicon (OR = 5.59; p = 0.05). Albuterol use was not associated with indoor pollutants in summer. Asthma severity was associated with specific indoor pollutants. Seasonal differences were observed by pollutant and by clinical index studied.

Sources of indoor particulate matter (PM) and outdoor air pollution in China in relation to asthma, wheeze, rhinitis and eczema among pre-school children: Synergistic effects between antibiotics use and PM10 and second hand smoke

Article

Full-text available

Apr 2019
ENVIRON INT

We studied indoor sources of indoor particulate matter (PM), outdoor air pollution and antibiotic use in relation to asthma, rhinitis and eczema among pre-school children and investigated synergistic effects between PM and antibiotics use. Children (3-6y) from randomly selected day care centres in seven cities across China were included (n = 39,782). Data on ambient temperature and air pollution were collected from local monitoring stations. Data on indoor PM sources (ETS, burning of incense or mosquito coils and biomass for cooking), antibiotics use and health (doctor diagnosed asthma and rhinitis, lifetime eczema, current wheeze and current rhinitis) were assessed by a parental questionnaire. Associations were calculated by multilevel logistic regression. Asthma diagnosis was associated with outdoor temperature, NO2 and burning mosquito coils. Rhinitis diagnosis was associated with NO2, ETS, gas cooking and burning biomass for cooking. Lifetime eczema was associated with temperature, PM10, NO2, ETS, biomass cooking and burning mosquito coils. Burning incense was associated with current wheeze and current rhinitis. Children using antibiotics had more asthma, wheeze, rhinitis, and eczema. Excluding children with respiratory infections did not change associations with antibiotics use. Antibiotics use enhanced the effects of ETS and PM10 (a synergistic effect). In conclusion, a warmer climate, outdoor NO2 and PM10, ETS, gas cooking and burning biomass, incense and mosquito coils can increase the risk of asthma, wheeze, rhinitis and eczema among pre-school children in China. Antibiotics use is a risk factor for childhood asthma, wheeze, rhinitis and eczema and ETS and outdoor PM10 can enhance the effect.

Pulmonary, inflammatory, and oxidative effects of indoor nitrogen dioxide in patients with COPD

Article

Oct 2023

Introduction Indoor nitrogen dioxide (NO 2 ) sources include gas heating, cooking, and infiltration from outdoors. Associations with pulmonary function, systemic inflammation, and oxidative stress in patients with chronic obstructive pulmonary disease (COPD) are uncertain. Methods We recruited 144 COPD patients at the VA Boston Healthcare System between 2012 and 2017. In-home NO 2 was measured using an Ogawa passive sampling badge for a week seasonally followed by measuring plasma biomarkers of systemic inflammation (C-reactive protein [CRP] and interleukin-6 [IL-6]), urinary oxidative stress biomarkers (8-hydroxy-2'deoxyguanosine [8-OHdG] and malondialdehyde [MDA]), and pre- and postbronchodilator spirometry. Linear mixed effects regression with a random intercept for each subject was used to assess associations with weekly NO 2 . Effect modification by COPD severity and by body mass index (BMI) was examined using multiplicative interaction terms and stratum-specific effect estimates. Results Median (25%ile, 75%ile) concentration of indoor NO2 was 6.8 (4.4, 11.2) ppb. There were no associations observed between NO 2 with CRP, 8-OHdG, or MDA. Although the confidence intervals were wide, there was a reduction in prebronchodilator FEV 1 and FVC among participants with more severe COPD (FEV 1 : –17.36 mL; –58.35, 23.60 and FVC: –28.22 mL; –91.49, 35.07) that was greater than in patients with less severe COPD (FEV 1 : –1.64 mL; –24.80, 21.57 and FVC: –6.22 mL; –42.16, 29.71). In participants with a BMI <30, there was a reduction in FEV 1 and FVC. Conclusions Low-level indoor NO 2 was not associated with systemic inflammation or oxidative stress. There was a suggestive association with reduced lung function among patients with more severe COPD and among patients with a lower BMI.

Analysis of inequalities in personal exposure to PM2.5: A modelling study for the Greater London school-aged population

Article

Full-text available

Sep 2023
SCI TOTAL ENVIRON

Indoor Air Pollution- Not the Lesser Evil!

Article

Jul 2023

How does climate change impact our patients?

Article

Apr 2023
CLEV CLIN J MED

Cooking with Natural Gas: Just the Facts Please

Article

Full-text available

Mar 2023
AM J RESP CRIT CARE

Impacts of residential indoor air quality and environmental risk factors on adult asthma-related health outcomes in Chicago, IL

Article

Full-text available

Nov 2022
J EXPO SCI ENV EPID

Background Residential environments are known to contribute to asthma. Objective To examine the joint impacts of exposures to residential indoor and outdoor air pollutants and housing risk factors on adult asthma-related health outcomes. Methods We analyzed >1-year of data from 53 participants from 41 homes in the pre-intervention period of the Breathe Easy Project prior to ventilation and filtration retrofits. Health outcomes included surveys of asthma control, health-related quality of life, stress, and healthcare utilizations. Environmental assessments included quarterly measurements of indoor and outdoor pollutants (e.g., HCHO, CO, CO2, NO2, O3, and PM), home walk-throughs, and surveys of environmental risk factors. Indoor pollutant concentrations were also matched with surveys of time spent at home to estimate indoor pollutant exposures. Results Cross-sectional analyses using mixed-effects models indicated that lower annual average asthma control test (ACT) scores were associated (p < 0.05) with higher indoor NO2 (concentration/exposure: β = −2.42/−1.57), indoor temperature (β = −1.03 to −0.94), and mold/dampness (β = −3.09 to −2.41). In longitudinal analysis, lower ACT scores were also associated (p < 0.05) with higher indoor NO2 concentrations (β = −0.29), PM1 (concentration/exposure: β = −0.12/−0.24), PM2.5 (concentration/exposure: β = −0.12/−0.26), and PM10 (concentration/exposure: β = 10.14/-0.28). Emergency department visits were associated with poorer asthma control [incidence rate ratio (IRR) = 0.84; p < 0.001], physical health (IRR = 0.95; p < 0.05), mental health (IRR = 0.95; p < 0.05), higher I/O NO2 ratios (IRR = 1.30; p < 0.05), and higher indoor temperatures (IRR = 1.41; p < 0.05). Significance Findings suggest that residential risk factors, including indoor air pollution (especially NO2 and particulate matter), higher indoor temperature, and mold/dampness, may contribute to poorer asthma control. Impact This study highlights the importance of residential indoor air quality and environmental risk factors for asthma control, health-related quality of life, and emergency department visits for asthma. Two timescales of mixed models suggest that exposure to indoor NO2 and particulate matter, higher indoor temperature, and mold/dampness was associated with poorer asthma control. Additionally, emergency department visits were associated with poorer asthma control and health-related quality of life, as well as higher I/O NO2 ratios and indoor temperatures. These findings deepen our understanding of the interrelationships between housing, air quality, and health, and have important implications for programs and policy.

Health effects of liquid and gaseous fuels for household energy use: Systematic evidence mapping

Article

Full-text available

Nov 2022
ENVIRON RES LETT

Background Exposure to household air pollution results in a substantial global health burden. The World Health Organization (WHO) Guidelines for Indoor Air Quality: Household Fuel Combustion stipulate emission rates for household energy devices should meet air quality guidelines and protect health. Liquefied petroleum gas (LPG), biogas, natural gas, and alcohol fuels are considered clean for health due to their low emissions at the point of use. In light of the ongoing energy transition and increasing emphasis on these fuels, it is imperative to provide an updated synthesis of the impacts of these fuels on health. Methods A systematic review was completed on the health effects of liquid and gaseous fuels for household energy use for cooking, heating, and lighting across high-, middle- and low-income countries. Comprehensive searches were undertaken in twelve international databases and selected studies were compiled into a new publicly available WHO Health Effects of Household Liquid & Gaseous Fuels Database, containing key study characteristics including pollutants and/or health outcomes measured. This database was then mapped to understand the breadth of evidence and potential gaps. Results From 48,130 search results, 587 studies were extracted for inclusion in the database on completion of the full-text review. Studies represented low-, middle- and high-income countries over several decades – there has been a substantial increase in evidence from low-and-middle income countries (LMICs) published in the last decade, particularly in Asia. Most evidence focused on LPG for cooking in LMICs or natural gas used in high-income countries for cooking and heating. Women were the most studied demographic, with self-reported health outcomes and symptoms being the most common assessment method. Particulate matter and nitrogen oxides were the most monitored pollutants. A wide array of health symptoms and disease and injury outcomes were assessed, and most concerned respiratory health. Conclusion This is the first time that evidence on the health effects of liquid and gaseous fuels for household energy use has been systematically catalogued and mapped. Most evidence concerned cooking and heating, with a paucity of information on the health effects from lighting. Limited evidence was available on the health effects of liquid fuels (such as alcohol fuels), with most studies concerning gaseous fuels. The WHO Health Effects of Household Liquid & Gaseous Fuels Database represents a valuable resource to enable the examination of the positive and negative health effects from these fuels.

Health Effects of Liquid and Gaseous Fuels for Household Energy Use: Systematic Evidence Mapping

Preprint

Full-text available

Oct 2022

Background Exposure to household air pollution results in a substantial global health burden. The World Health Organization (WHO) Guidelines for Indoor Air Quality: Household Fuel Combustion stipulate emission rates for household energy devices should meet air quality guidelines and protect health. Liquefied petroleum gas (LPG), biogas, natural gas, and alcohol fuels are considered clean for health due to their low emissions at the point of use. In light of the ongoing energy transition and increasing emphasis on these fuels, it is imperative to provide an updated synthesis of the impacts of these fuels on health. Methods A systematic review was completed on the health effects of liquid and gaseous fuels for household energy use for cooking, heating, and lighting across high-, middle- and low-income countries. Comprehensive searches were undertaken in twelve international databases and selected studies were compiled into a new publicly available WHO Health Effects of Household Liquid & Gaseous Fuels Database, containing key study characteristics including pollutants and/or health outcomes measured. This database was then mapped to understand the breadth of evidence and potential gaps. Results From 48,130 search results, 587 studies were extracted for inclusion in the database on completion of the full-text review. Studies represented low-, middle- and high-income countries over several decades – there has been a substantial increase in evidence from low-and-middle income countries (LMICs) published in the last decade, particularly in Asia. Most evidence focused on LPG for cooking in LMICs or natural gas used in high-income countries for cooking and heating. Women were the most studied demographic, with self-reported health outcomes and symptoms being the most common assessment method. Particulate matter and nitrogen oxides were the most monitored pollutants. A wide array of health symptoms and disease and injury outcomes were assessed, and most concerned respiratory health. Conclusion This is the first time that evidence on the health effects of liquid and gaseous fuels for household energy use has been systematically appraised. Most evidence concerned cooking and heating, with a paucity of information on the health effects from lighting. Limited evidence was available on the health effects of liquid fuels (such as alcohol fuels), with most studies concerning gaseous fuels. The WHO Health Effects of Household Liquid & Gaseous Fuels Database represents a valuable resource to examine both the positive and negative health effects from these fuels.

Overcoming State-Level Preemption to Electrify New Buildings: a Philadelphia Case Study

Article

Full-text available

Oct 2022

The use of natural gas in heating and cooking negatively impacts environmental and human health. As government investments in clean energy production continue to increase, replacing natural gas appliances with electric alternatives is imperative to both reduce greenhouse gas emissions and protect public health. As a large US city with robust emissions reduction goals, Philadelphia, PA must significantly reduce natural gas use in buildings. However, many states, including PA, have advanced legislation that preemptively restricts municipalities from banning natural gas use. Using Philadelphia as a case study, we propose policy options, including electric appliance rebates, electrification incentives, and building efficiency standards, that US municipalities can pursue to circumvent state preemption laws in electrifying new construction, significantly reducing natural gas demand, and advancing their net-zero emissions goals.

Home Energy Upgrades as a Pathway to Home Decarbonization in the US: A Literature Review

Article

Full-text available

Aug 2022

This work aims to characterize how home energy upgrade projects and programs in the US have evolved over the past decade. It also identifies what changes are needed to drive expansion of the US energy retrofit market in such a way that addresses carbon emissions from buildings, improves resilience and upgrades the housing stock. This review focuses on whole-home energy upgrades, targeting deep energy retrofit savings of >30%. The topics we cover include trends in home electrification, US and European home energy upgrade programs, energy upgrade measure costs, business economics, and health effects. Key changes in project design noted in this review include: (1) the electrification of dwellings with rapidly improving heat pump systems and low-cost solar photovoltaic technology; and (2) a shift away from high-cost building envelope strategies and towards more traditional home performance/weatherization envelope upgrades. Promising program design strategies covered include: (1) end-use electrification programs; (2) novel financing approaches; (3) the use of carbon-based program and project metrics; and (4) “one-stop shop” programs. Based on the existing market barriers, we suggest that the industry should adopt new project performance metrics. Additionally, market drivers are needed to spur widespread energy upgrades in the US housing stock. Costs must be reduced, and projects designed to appeal to homeowners and contractors.

Quantifying the impacts of clean cooking transitions on future health-age trajectories in South Africa

Article

Full-text available

May 2022
ENVIRON RES LETT

Reliance on highly polluting cooking technologies poses a significant risk for human health. This study quantifies and compares the impact of different clean cooking access scenarios on future health-age trajectories among population subgroups in South Africa. Using microdata from five waves of the South African National Income Dynamics Study (NIDS), we develop a dynamic microsimulation model and a composite metric of individual health status that is used to explore how health status changes under alternative access scenarios for the period 2010-2030. We find that there are clear gains of using clean cooking technologies for population health, and that electrification alone doesn't improve health status, if it is not accompanied by an increase in the use of clean cooking technologies in homes. Our results imply that achieving universal access to clean cooking in South Africa can by itself improve average population health by almost 4% by 2030 compared to a scenario without clean cooking technologies, with the health of individuals of genders and races with the poorest health and well-being endowments improving the most. Thus, clean cooking can contribute to narrowing existing inequalities by improving health for the most vulnerable population groups that disproportionately depend on polluting cooking technologies.

Methane and NO x Emissions from Natural Gas Stoves, Cooktops, and Ovens in Residential Homes

Article

Full-text available

Jan 2022

Natural gas stoves in >40 million U.S. residences release methane (CH4)─a potent greenhouse gas─through post-meter leaks and incomplete combustion. We quantified methane released in 53 homes during all phases of stove use: steady-state-off (appliance not in use), steady-state-on (during combustion), and transitory periods of ignition and extinguishment. We estimated that natural gas stoves emit 0.8-1.3% of the gas they use as unburned methane and that total U.S. stove emissions are 28.1 [95% confidence interval: 18.5, 41.2] Gg CH4 year-1. More than three-quarters of methane emissions we measured originated during steady-state-off. Using a 20-year timeframe for methane, annual methane emissions from all gas stoves in U.S. homes have a climate impact comparable to the annual carbon dioxide emissions of 500 000 cars. In addition to methane emissions, co-emitted health-damaging air pollutants such as nitrogen oxides (NOx) are released into home air and can trigger respiratory diseases. In 32 homes, we measured NOx (NO and NO2) emissions and found them to be linearly related to the amount of natural gas burned (r2 = 0.76; p ≪ 0.01). Emissions averaged 21.7 [20.5, 22.9] ng NOx J-1, comprised of 7.8 [7.1, 8.4] ng NO2 J-1 and 14.0 [12.8, 15.1] ng NO J-1. Our data suggest that families who don't use their range hoods or who have poor ventilation can surpass the 1-h national standard of NO2 (100 ppb) within a few minutes of stove usage, particularly in smaller kitchens.

Clean electrification of the U.S. economy

Technical Report

Full-text available

Dec 2021

The global energy system is undergoing the largest and fastest transformation since the Industrial Revolution. Breakthroughs in renewable production and storage have made solar and wind the cheapest and cleanest energy ever available. Consequently, solar, wind, and batteries now make up more than 90% of all new energy production built each year. Because the energy scene is changing so rapidly, there is a lot of misunderstanding and misinformation (just YouTube “renewables” and you’ll see what we mean). Even those of us in the industry can get out of date in a matter of months. As a group of researchers, students, and community members, we prepared this overview of the renewable revolution based on more than 300 peer-reviewed studies, technical reports, and public articles. We were asked by local and state lawmakers to prepare this report, but we received no funding to do this research.

Associations between indoor environment in residential buildings in wet and dry seasons and health of students in upper northern Thailand

Article

Full-text available

Jun 2021

We performed a repeated questionnaire study on home environment and health (six medical symptoms) in 1159 junior high school students (age 12.8 ± 0.7 years) in upper northern Thailand in wet and dry seasons. Data on outdoor temperature, relative humidity (RH), and air pollution were collected from nearest monitoring station. Odds ratios (OR) were calculated by multi‐level logistic regression. Most common symptoms were rhinitis (62.5%), headache (49.8%), throat (42.8%), and ocular symptoms (42.5%). Ocular symptoms were more common at lower RH and rhinitis more common in dry season. Water leakage (28.2%), indoor mold (7.1%), mold odor (4.1%), and windowpane condensation (13.6%) were associated with all six symptoms (ORs: 1.3–3.5). Other risk factors included cat keeping, environmental tobacco smoke (ETS), other odor than mold odor, gas cooking, and cooking with biomass fire. Biomass burning inside and outside the home for other reasons than cooking was associated with all six symptoms (ORs: 1.5–2.6). Associations between home environment exposure and rhinitis were stronger in wet season. In conclusion, dampness‐related exposure, windowpane condensation, cat keeping, ETS, gas cooking, and biomass burning can impair adolescent health in upper northern Thailand. In subtropical areas, environmental health effects should be investigated in wet and dry seasons.

Factors Impacting Range Hood Use in California Houses and Low-Income Apartments

Article

Full-text available

Nov 2020
Int J Environ Res Publ Health

Venting range hoods can control indoor air pollutants emitted during residential cooktop and oven cooking. To quantify their potential benefits, it is important to know how frequently and under what conditions range hoods are operated during cooking. We analyzed data from 54 single family houses and 17 low-income apartments in California in which cooking activities, range hood use, and fine particulate matter (PM2.5) were monitored for one week per home. Range hoods were used for 36% of cooking events in houses and 28% in apartments. The frequency of hood use increased with cooking frequency across homes. In both houses and apartments, the likelihood of hood use during a cooking event increased with the duration of cooktop burner use, but not with the duration of oven use. Actual hood use rates were higher in the homes of participants who self-reported more frequent use in a pre-study survey, but actual use was far lower than self-reported frequency. Residents in single family houses used range hoods more often when cooking caused a discernible increase in PM2.5. In apartments, residents used their range hood more often only when high concentrations of PM2.5 were generated during cooking.

Exposure to outdoor light at night and risk of breast cancer: A systematic review and meta-analysis of observational studies

Article

Dec 2020
ENVIRON POLLUT

Chengyang Hu

Recent epidemiological studies have explored effects of light at night (LAN) exposure on breast cancer, but reported inconsistent findings. We performed a systematic review and meta-analysis of available evidence regarding the association of LAN assessed by satellite data with breast cancer. We conducted a systematic PubMed, Web of Science, and EMBASE database literature search until August 2020. Random-effects meta-analysis was applied to synthesis risk estimates. Heterogeneity was measured using statistics of Cochran’s Q, I2, and Tau2 (τ2). We assessed publication bias through funnel plot and Egger’s test. Moreover, subgroup analyses according to study design and menopausal status were performed. Risk of bias (RoB) of each included study was assessed using a domain-based RoB assessment tool. The confidence in the body of evidence was appraised using the GRADE approach for level-of-evidence translation. A total of 1157 studies were identified referring to LAN and breast cancer, from which 6 were included for quantitative synthesis. We found a significantly higher odds of breast cancer in the highest versus the lowest category of LAN exposure (OR = 1.11, 95% CI: 1.06, 1.16; I2 = 0.0%). In the subgroup analyses stratified by menopausal status and study design, significant association was found in postmenopausal women (OR = 1.07, 95% CI = 1.00, 1.13) and cohort studies (OR = 1.11, 95% CI = 1.05, 1.18), while the summary estimates of premenopausal women and case-control studies showed no significance. The level of evidence for the association of LAN exposure and breast cancer risk was graded as “moderate” with “probably low” RoB according to the NTP/OHAT framework. In conclusion, this study suggests a link of LAN exposure with risk of breast cancer. Further high-quality prospective studies, especially performed in low-to middle-income countries with improvement in the area of LAN exposure assessment are needed to advance this field.

Respiratory health effects of residential individual and cumulative risk factors in children living in two cities of the Pearl River Delta Region, China

Article

Full-text available

Oct 2020

Background: Indoor environment is complex, with many factors potentially interacting with each other to affect health. However, previous studies have usually focused on effect of a single factor. Assessment of the combined effects of multiple factors can help with understanding the overall health risk. Methods: A cross-sectional study was conducted among 2,306 school children in Guangzhou and Shenzhen. Questionnaire data on respiratory symptoms and diseases were collected along with sociodemographic and residential environmental information. A subset of children (N=987) were measured for their lung function. A random forest algorithm was applied to screen the top-ranked indoor environmental exposure variables and to form a composite index for cumulative risk of indoor pollution (CRIP). Logistic regressions were conducted to analyze the independent effect of single indoor environmental risk factors and the combined effect of CRIP on children's respiratory health. Multiple linear regressions were used to examine the independent and combined effects of indoor environmental exposure on lung function. Results: We found that home dampness and molds as well as environmental tobacco smoke (ETS) were significantly and independently associated with increased prevalence of children's respiratory symptoms and diseases and with reduced lung function. A higher CRIP level was significantly associated with increased risk of cough with cold (OR =1.37, 95% CI: 1.05-1.79) and wheeze (OR =2.71, 95% CI: 1.16-6.34). A higher CRIP level was also associated with reduced lung function measured as FVC, FEV1, PEF, FEF25%, FEF25-75% and VC. Conclusions: In children living in the subtropical region of the Pearl River Delta, home dampness and the presence of mold as well as ETS were individual risk factors for children's respiratory health. The composite CRIP index was associated with respiratory symptoms and lung function, suggesting the utility of this index for predicting the combined effects of multiple risk factors.

An enhanced procedure for urban mobile methane leak detection

Article

Full-text available

Oct 2020

Leaked methane from natural gas distribution pipelines is a significant human and environmental health problem in urban areas. To assess this risk, urban mobile methane leak surveys were conducted, using innovative methodology, on the streets of Hartford, Danbury, and New London, Connecticut, in March 2019. The Hartford survey was done to determine if results from a 2016 survey (Keyes et al., 2019) were persistent, and surveys in additional towns were done to determine if similar findings could be made using an identical approach. Results show that Hartford continues to be problematic, with approximately 3.4 leaks per road mile observed in 2016 and 4.3 leaks per mile estimated in 2019, similar to that previously found in Boston, Massachusetts (Phillips et al., 2013). A preliminary estimate of methane leaks in Hartford is 0.86 metric tonnes per day (or 313 metric tonnes per year), equivalent to 42,840 cubic feet per day of natural gas, and a daily gas consumption of approximately 214 U.S. households. Moreover, the surveys and analyses done for Danbury and New London also reveal problematic leaks, particularly for Danbury with an estimated 3.6 leaks per mile. Although road miles covered in New London were more limited, the survey revealed leak-prone areas, albeit with a range of methane readings lower than those in Hartford and Danbury. Data collection methods for all studies is first reported here and are readily transferable to similar urban settings. This work demonstrates the actionable value that can be gained from data-driven evaluations of urban pipeline performance, and if supplemented with a map of leak-prone pipe geo-location, and information on pipeline operating pressures, will provide a spatial database facilitating proactive repair and replacement of leak-prone urban pipes, a considerable improvement compared to reactive mitigation of human-reported leaks. While this work pertains to the selected urban towns in the Northeast, it exemplifies issues and opportunities nationwide in the United States.

Human epidemiological evidence about the association between air pollution exposure and gestational diabetes mellitus: Systematic review and meta-analysis

Article

Oct 2019

Background: Previous studies have shown that ambient air pollution exposure can increase the risk of type 2 diabetes mellitus (T2DM) significantly. In consideration of the common underlying pathophysiologic mechanisms, exposure to air pollution may also increase the risk of gestational diabetes mellitus (GDM), but the current evidence was inconsistent and has not well been systematically reviewed. Our goal was to perform a systematic review and meta-analysis assessing the association between air pollution exposure and GDM. Methods: An extensive literature search was conducted in selected electronic databases for related human epidemiological studies published in English language. Summary effect estimates were calculated using random-effect models for a) risk per unit increase in continuous air pollutant concentration and b) risk of high versus low exposure level in individual study if each exposure that had been examined in ≥2 studies. We evaluated the heterogeneity using Cochran's Q test and quantified it by I2 statistic. Publication bias was also evaluated through the funnel plot when sufficient number of studies are available. Results: A total of 11 studies evaluating the association between GDM and exposure to air pollution were identified finally. The summary odds ratio (OR) for incidence of GDM following a 10 μg/m3 increase in PM2.5 exposure during the second trimester was 1.04 (95% Confidence Interval (CI): 1.01, 1.09) and in NOx during the first trimester was 1.03 (95%CI: 1.00, 1.07) per 10 ppb increase, while for high versus low SO2 exposure during the second trimester was 1.25 (95%CI: 1.02, 1.53). High heterogeneity among study-specific results in majority of the analyses were observed, and attributed to different exposure assessment methods, populations, study locations, and covariates adjustment. Publication bias cannot be excluded because of the inclusion of small number of studies. Conclusions: The present study supports the evidence that air pollution exposure increases the risk the GDM, albeit the existence of high heterogeneity. Further studies are necessary to elaborate the suggestive associations. These results are of public health significance since worsening air pollution in developing countries has been expected to increase the risk of GDM development.

Pathways to a healthy net-zero future: report of the Lancet Pathfinder Commission

Article

Nov 2023
LANCET

Peninah Murage

Should we use natural gas in our homes? Risk perceptions from the U.S

Article

Oct 2023

Household Air Pollution: A Dire Need Of Awareness In Pakistan

Article

Full-text available

Sep 2023
J Pakistan Med Assoc

Dear Editor, Household Air Pollution [HAP] has proven to be associated with an increased risk of acquiring asthma, lung cancer, pulmonary tuberculosis, and acute respiratory infections in adults and children, along with Chronic Obstructive Pulmonary Disease [COPD], cerebrovascular disease, ischemic heart disease, low birth weight, and stillbirth [1]. This pollution is caused primarily by the absence of clean fuels, which includes electricity, biogas, natural gas, liquefied petroleum gas (LPG), solar, or alcohol fuels. Owing to the absence of clean fuels, individuals resort to the use of biomass to meet their needs, exposing themselves to the detrimental effects of biomass usage. Unfortunately, Pakistan is one of the worst-faring victims of this predicament. As of 2020, only 49.3% of Pakistanis primarily relied on clean fuels and technologies for cooking [2]. With only 26% of rural areas having access to clean fuels, traditional, inefficient three-stone stoves for biomass combustion are typical in rural areas[2][3]. Such stoves expel poisonous gasses, including Nitrogen oxides, Carbon monoxide, and formaldehyde, in addition to several toxic organic compounds depending on the type of biomass used, all detrimental to human health [4]. In urban areas, especially in winter, widespread gas shortages are prevalent, restricting an unknown number of citizens to biomass combustion for their day-to-day purposes. In both scenarios, the harms of HAP are imminent. Unfortunately, using gas stoves in poorly ventilated areas also shows milder effects of HAP [5]. Alarmingly, despite the adverse impact and the high prevalence of HAP, the matter remains neglected, with only very few studies connecting the above-stated health risks with the Pakistani population, evaluating the burden Pakistan bears because of HAP, and assessing the correct strategies for intervention. Such studies would result in implementing specific research-backed mitigation strategies customized to be specifically applicable to different socioeconomic backgrounds and regions of Pakistan, for example, efficient ventilatory systems relevant to Pakistani houses designed to reduce HAP. In the meantime, examples of general policies include, but are not limited to, television advertisements, awareness drives, and allotting larger budgets towards cleaner fuel provision. For people utilizing primitive three-stone stoves, a plancha stove, comprising simply a stove and a chimney, can also be provided. The usage of such stoves is associated with a significantly reduced exposure to HAP [6]. Individually, when operating stoves for any purpose, it is crucial to prioritize ventilation. ---Continue

The gas stove-childhood asthma kerfuffle: A teaching opportunity

Article

Mar 2023

Louis Anthony Tony Cox

Several recent news stories have alarmed many politicians and members of the public by reporting that indoor air pollution from gas stoves causes about 13% of childhood asthma in the United States. Research on the reproducibility and trustworthiness of epidemiological risk assessments has identified a number of common questionable research practices (QRPs) that should be avoided to draw sound causal conclusions from epidemiological data. Examples of such QRPs include claiming causation without using study designs or data analyses that allow valid causal inferences; generalizing or transporting risk estimates based on data for specific populations, time periods, and locations to different ones without accounting for differences in the study and target populations; claiming causation without discussing or quantitatively correcting for confounding, external validity bias, or other biases; and not mentioning or resolving contradictory evidence. We examine the recently estimated gas stove-childhood asthma associations from the perspective of these QRPs and conclude that it exemplifies all of them. The quantitative claim that about 13% of childhood asthma in the United States could be prevented by reducing exposure to gas stove pollution is not supported by the data collected or by the measures of association (Population Attributable Fractions) used to analyze the data. The qualitative finding that reducing exposure to gas stove pollution would reduce the burden of childhood asthma in the United States has no demonstrated validity. Systematically checking how and whether QRPs have been addressed before reporting or responding to claims that everyday exposures cause substantial harm to health might reduce social amplification of perceived risks based on QRPs and help to improve the credibility and trustworthiness of published epidemiological risk assessments.

Association between gas stove use and childhood asthma in the Canadian CHILD Cohort Study

Article

Jun 2023

Air pollution exposure when cooking with electricity compared to gas

Preprint

Full-text available

Apr 2023

We report small-sample evidence from a randomized experiment among a set of urban Ecuadorian households who owned both electric induction and gas stoves. We randomly assigned households to cook only with one stove during a prescribed two-day monitoring period, and then cook only with the other stove in a subsequent two-day period. The order of stove use was randomized, and air pollution was measured during each period. We found that mean 48-hour personal NO 2 exposure was 9.9 ppb higher (95% CI, 4.5-15.3)--- a 50% increase over the 48-hour induction mean --- when households were randomized to gas as compared to induction. Mean kitchen area NO 2 concentrations were 1 ppb higher (95% CI, 0.4-2.1) (a 6% increase) and mean personal PM 2.5 exposure was 11 μgm ⁻³ higher (95% CI, -0.1-22.8) (a 44% increase) during study periods when randomized to gas. We use time-resolved cooking and pollution data to illustrate that these differences are driven by LPG cooking, which was associated with a 5.0 ppb increase in 5-minute average NO 2 kitchen area concentrations (95% CI, 3.4-6.7) and a 20.8 μgm ⁻³ increase in 5-minute average personal PM 2.5 exposure (95% CI 8.9-32.6). In contrast, cooking with induction was not associated with changes to short-term NO 2 kitchen area concentrations, though it was associated with short-term increased personal PM 2.5 exposure (10.8, 95% CI, 5.7-15.9).

Correspondence on "Home is Where the Pipeline Ends: Characterization of Volatile Organic Compounds Present in Natural Gas at the Point of the Residential End User"

Article

Jan 2023
ENVIRON SCI TECHNOL

Developmental Origins of Chronic Respiratory Diseases

Chapter

Dec 2022

The concept of the early life developmental origins of health and disease (DOHaD) in adults has stimulated a new approach to understanding disease trajectories, with major public health implications. Indeed, the principle of the 'lifecourse of disease' now influences health policies internationally. Environmental influences during pregnancy and early life that affect lifelong health are well documented, but there is a new focus on the preconception period and the significance of paternal health on the fetus. This fully revised second edition highlights scientific and clinical advances in the field, exploring new understanding of mechanisms such as epigenetics and the increasingly recognised role of external influences, including pollution. The book is structured logically, covering environment, clinical outcomes, mechanisms of DOHaD, interventions throughout the lifespan and finally implications for public health and policy. Clinicians and scientists alike will improve their understanding of the developmental origins of health and disease with this essential text.

The Inflation Reduction Act - a Historic Piece of Climate and Health Legislation

Article

Sep 2022

The adsorption of NO2, SO2, and O3 molecules on the Al-doped stanene nanotube: a DFT study

Article

Sep 2022

Adsorption of pollutant gas molecules (NO2, SO2, and O3) on the surface of the Al-doped stanene nanotube was investigated within the first principle calculations of density functional theory (DFT). Adsorption mechanisms were studied by analyzing optimized structures, band structures, projected density of states (PDOS), charge density difference (CDD), molecular orbitals, and band theory. Investigation of charge transfer by Mulliken population showed that NO2 accumulated while SO2 and O3 depleted charge density on the Al-doped nanotube. The differences in band structures before and after adsorption implied that the electronic characteristics of Al-doped nanotube changed dramatically in case of NO2 adsorption, which converted Al-doped nanotube to a semiconductor material. High adsorption energy and the significant overlap between PDOS spectra indicated that the adsorption process was chemisorption for NO2, SO2, and O3 on the doped nanotube with the obtained order of O3 > SO2 > NO2. The results showed that the adsorption of NO2, SO2, and O3 occurred on the Al-doped stanene nanotube, and that all the three gas molecules could be detected by Al-doped stanene nanotube with various detection strengths.

Childhood asthma and household exposures to nitrogen dioxide and fine particles: a triple-crossover randomized intervention trial

Article

Jul 2022

Objective: Triple-crossover randomized controlled intervention trial to test whether reduced exposure to household NO2 or fine particles results in reduced symptoms among children with persistent asthma. Methods: Children (n = 126) aged 5-11 years with persistent asthma living in homes with gas stoves and levels of NO2 15 ppb or greater recruited in Connecticut and Massachusetts (2015-2019) participated in an intervention involving three air cleaners configured for: (1) NO2 reduction: sham particle filtration and real NO2 scrubbing; (2) particle filtration: HEPA filter and sham NO2 scrubbing; (3) control: sham particle filtration and sham NO2 scrubbing. Air cleaners were randomly assigned for 5-week treatment periods using a three-arm crossover design. Outcome was number of asthma symptom-days during final 14 days of treatment. Treatment effects were assessed using repeated measures, linear mixed models. Results: Measured NO2 was lower (by 4 ppb, p < .0001) for NO2-reducing compared to control or particle-reducing treatments. NO2-reducing treatment did not reduce asthma morbidity compared to control. In analysis controlling for measured NO2, there were 1.8 (95% CI -0.3 to 3.9, p = .10) fewer symptom days out of 14 in the particle-reducing treatment compared to control. Conclusions: It remains unknown if using an air cleaner alone can achieve levels of NO2 reduction large enough to observe reductions in asthma symptoms. We observed that in small, urban homes with gas stoves, modest reductions in asthma symptoms occurred using air cleaners that remove fine particles. An intervention targeting exposures to both NO2 and fine particles is complicated and further research is warranted. Registration number: NCT02258893.

Integration of Indoor Air Quality Prediction into Healthy Building Design

Article

Full-text available

Jun 2022

Healthy building design is an emerging field of architecture and building engineering. Indoor air quality (IAQ) is an inevitable factor that should be considered in healthy building design due to its demonstrated links with human health and well-being. This paper proposes to integrate IAQ prediction into healthy building design by developing a simulation toolbox, termed i-IAQ, using MATLAB App Designer. Within the i-IAQ, users can input information of building layout and wall-openings and select air pollutant sources from the database. As an output, the toolbox simulates indoor levels of carbon dioxide (CO2), total volatile organic compounds (TVOC), inhalable particles (PM10), fine particles (PM2.5), nitrogen dioxide (NO2), and ozone (O3) during the occupied periods. Based on the simulation results, the toolbox also offers diagnosis and recommendations to improve the design. The accuracy of the toolbox was validated by a case study in an apartment where physical measurements of air pollutants took place. The results suggest that designers can integrate the i-IAQ toolbox in building design, so that the potential IAQ issues can be resolved at the early design stage at a low cost. The paper outcomes have the potential to pave a way towards more holistic healthy building design, and novel and cost-effective IAQ management.

Poor indoor climate: Its impact on health and life satisfaction, as well as its wider socio-economic costs

Technical Report

Full-text available

Mar 2022

There is strong evidence that a poor indoor climate has a significant impact on people's health and well-being, and that in turn has wider socio-economic consequences, such as via its impact on work attendance, productivity and performance. Four indoor hazards in particular were identified and used in the analysis: Damp and mould; Noise pollution; Indoor temperature (excess cold), and; Lack of daylight. The objective of this study was to undertake a detailed analysis of the impact of the indoor climate across all age groups in the EU and the UK, Norway and Switzerland.

Energy Poverty and Health Vulnerability: A Global Analysis

Article

Jan 2022

Ambient air pollution and the risk of acute myocardial infarction and stroke: A national cohort study

Article

Aug 2021
ENVIRON RES

We used a large national cohort in Canada to assess the incidence of acute myocardial infarction (AMI) and stroke hospitalizations in association with long-term exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3). The study population comprised 2.7 million respondents from the 2006 Canadian Census Health and Environment Cohort (CanCHEC), followed for incident hospitalizations of AMI or stroke between 2006 and 2016. We estimated 10-year moving average estimates of PM2.5, NO2, and O3, annually. We used Cox proportional hazards models to examine the associations adjusting for various covariates. For AMI, each interquartile range (IQR) increase in exposure was found to be associated with a hazard ratio of 1.026 (95% CI: 1.007–1.046) for PM2.5, 1.025 (95% CI: 1.001–1.050) for NO2, and 1.062 (95% CI: 1.041–1.084) for O3, respectively. Similarly, for stroke, an IQR increase in exposure was associated with a hazard ratio of 1.078 (95% CI: 1.052–1.105) for PM2.5, 0.995 (95% CI: 0.965–1.030) for NO2, and 1.055 (95% CI: 1.028–1.082) for O3, respectively. We found consistent evidence of positive associations between long-term exposures to PM2.5, and O3, and to a lesser degree NO2, with incident AMI and stroke hospitalizations.

Indoor Air Pollution Sources and Respiratory Symptoms in Bronchopulmonary Dysplasia

Article

May 2020
J Pediatr

Objective To evaluate the impact of exposure to indoor air pollution on respiratory health outcomes (healthcare utilization, symptoms, medication use) in infants and children with bronchopulmonary dysplasia (BPD). Study design A total of 244 subjects were included from the Johns Hopkins Bronchopulmonary Dysplasia registry. Parents completed an environmental exposure questionnaire including secondhand smoke and indoor combustion (gas/propane heat, gas or wood stove, gas/wood burning fireplace) exposures in the home. Respiratory symptoms, both acute (healthcare utilization, steroid/antibiotic use) and chronic (cough/wheeze, nocturnal cough, use of beta-agonists, tolerance of physical activity), were also collected. Results Three-quarters of the infants were exposed to at least 1 combustible source of air pollution in the home, and this exposure was associated with an increased risk of hospitalization in infants and children on home respiratory support. Only 14% of the study population reported secondhand smoke exposure, but we found that this was associated with chronic respiratory symptoms, including activity limitation and nocturnal cough. Infants on respiratory support also had increased daytime cough and wheezing. Approximately one-third reported having an air purifier in the home, and its presence attenuated the effect of secondhand smoke exposure on reported activity limitation. Conclusions Exposure to combustible sources of indoor air pollution was associated with increased respiratory morbidity in a group of high risk of infants with BPD. Our results support that indoor air pollution is a modifiable risk factor for respiratory health in infants with BPD.

Associations with Home Environment for Asthma, Rhinitis and Dermatitis

Chapter

Jan 2020

Juan Wang

Asthma, rhinitis and dermatitis are common diseases that can affect both children and adults. The prevalence of asthma and allergic diseases is still increasing, especially in low- and middle-income countries. Home environment is important as we spend two-third of our time in dwellings. Common risk factors in dwellings associated with asthma, rhinitis and dermatitis can include environment tobacco smoke (ETS), allergens, dampness and mould, insufficient ventilation, indoor painting, renovation, new furniture/materials and indoor chemical emissions from building materials. The most consistent risk factors for asthma, rhinitis and dermatitis are indoor allergens, environment tobacco smoke (ETS) and dampness and indoor mould. There is a tendency that high ventilation flow in dwellings is associated with reduced asthma symptoms. Indoor activities including painting, renovation and new furniture/materials are associated with asthma, rhinitis and eczema mainly among children. The most common indoor chemicals associated with asthma are formaldehyde and volatile organic compounds (VOCs). Some studies indicate that phthalate esters can be associated with asthma among children. Moreover, measured nitrogen dioxide (NO2) concentrations in dwellings are associated with childhood asthma.

Vorkommen und zoonotische Übertragung multiresistenter Erreger in Deutschland - Occurrence and zoonotic transmission of multidrug-resistant Bacteria in Germany

Book

Jun 2019

[Article in German] Background Multidrug-resistant microorganisms (MDRO) occur both in animals and humans in Germany. For providing guidance for the prevention of MDRO in households and outside healthcare facilities and the prevention of zoonotic transmission, it is essential to describe the epidemiology of major MDRO. Methods This review describes current data about the occurrence of MDRO in humans, pets, hobby animals such as horses and livestock in Germany. In addition, it describes knowledge about the transmission of MDRO between animals and humans. Results In Germany, many studies have assessed the prevalence of asymptomatic carriage by methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-Lactamase (ESBL) producing enterobacteria amongst the human general population, persons with exposure to food-producing animals, livestock, dogs, cats and horses. The clinical relevance of these MDRO has also been studied extensively. However, for many MDRO that have an impact on human medicine (e.g. vancomycin-resistant enterococci, VRE; carbapenemase-producing enterobacteria; oxazolidinon-resistant enterococci or colistin-resistant enterobacteria) there is limited information regarding their occurrence, which refers to single reservoirs (e.g. humans or livestock) or is from case reports only. Conclusions The epidemiological information provided in this review helps to make recommendations aiming to prevent the zoonotic spread of MDRO as well as transmission outside healthcare settings.

The National Human Activity Pattern Survey (NHAPS): A Resource for Assessing Exposure to Environmental Pollutants

Article

Full-text available

Jan 2001

Bias in Meta-Analysis Detected by a Simple, Graphical Test

Article

Full-text available

Sep 1997

Objective: Funnel plots (plots of effect estimates against sample size) may be useful to detect bias in meta-analyses that were later contradicted by large trials. We examined whether a simple test of asymmetry of funnel plots predicts discordance of results when meta-analyses are compared to large trials, and we assessed the prevalence of bias in published meta-analyses. Design: Medline search to identify pairs consisting of a meta-analysis and a single large trial (concordance of results was assumed if effects were in the same direction and the meta-analytic estimate was within 30

Combined exposure to dog and indoor pollution: Incident asthma in a high-risk birth cohort

Article

Full-text available

Feb 2011
EUR RESPIR J

The impact of single exposures on asthma development is better understood than the effect of multiple exposures. The objective of the present study was to evaluate the effect of combined early exposure to dog allergen (Can-f1) plus indoor nitrogen dioxide (NO₂) or environmental tobacco smoke (ETS) on asthma and bronchial hyperreactivity (BHR) in a high-risk birth cohort. We also aimed to assess atopy's impact on the effects of these exposures. Peri-birth ETS exposure was measured using cord blood cotinine (CCot). During year 1, atopy, NO₂, Can-f1, and urinary cotinine (UCot) were measured. At 7 yrs of age, 380 children were assessed for asthma and BHR. Exposure effects were determined using stepwise multiple linear regression. Co-exposure to elevated Can-f1 and NO₂, or Can-f1 and ETS (CCot), increased risk for asthma, relative to having neither such exposure (OR 4.8 (95% CI 1.1-21.5) and 2.7 (1.1-7.1), respectively); similar risks resulted when substituting dog ownership for allergen. Atopy increased asthma and BHR risk associated with several exposures; notably, atopy with elevated UCot, relative to atopy without such exposure, increased risk of BHR (OR 3.1 (95% CI 1.1-8.6)). In a high-risk birth cohort, early co-exposure to Can-f1 and NO₂ or ETS increased the risk of incident asthma. Atopy increased the risk of asthma and BHR associated with ETS.

Effects of improved home heating on asthma in community dwelling children: Randomised controlled trial

Article

Full-text available

Sep 2008
Br Med J

To assess whether non-polluting, more effective home heating (heat pump, wood pellet burner, flued gas) has a positive effect on the health of children with asthma. Randomised controlled trial. Households in five communities in New Zealand. 409 children aged 6-12 years with doctor diagnosed asthma. Installation of a non-polluting, more effective home heater before winter. The control group received a replacement heater at the end of the trial. The primary outcome was change in lung function (peak expiratory flow rate and forced expiratory volume in one second, FEV(1)). Secondary outcomes were child reported respiratory tract symptoms and daily use of preventer and reliever drugs. At the end of winter 2005 (baseline) and winter 2006 (follow-up) parents reported their child's general health, use of health services, overall respiratory health, and housing conditions. Nitrogen dioxide levels were measured monthly for four months and temperatures in the living room and child's bedroom were recorded hourly. Improvements in lung function were not significant (difference in mean FEV(1) 130.7 ml, 95% confidence interval -20.3 to 281.7). Compared with children in the control group, however, children in the intervention group had 1.80 fewer days off school (95% confidence interval 0.11 to 3.13), 0.40 fewer visits to a doctor for asthma (0.11 to 0.62), and 0.25 fewer visits to a pharmacist for asthma (0.09 to 0.32). Children in the intervention group also had fewer reports of poor health (adjusted odds ratio 0.48, 95% confidence interval 0.31 to 0.74), less sleep disturbed by wheezing (0.55, 0.35 to 0.85), less dry cough at night (0.52, 0.32 to 0.83), and reduced scores for lower respiratory tract symptoms (0.77, 0.73 to 0.81) than children in the control group. The intervention was associated with a mean temperature rise in the living room of 1.10 degrees C (95% confidence interval 0.54 degrees C to 1.64 degrees C) and in the child's bedroom of 0.57 degrees C (0.05 degrees C to 1.08 degrees C). Lower levels of nitrogen dioxide were measured in the living rooms of the intervention households than in those of the control households (geometric mean 8.5 microg/m(3) v 15.7 microg/m(3), P<0.001). A similar effect was found in the children's bedrooms (7.3 microg/m(3) v 10.9 microg/m(3), P<0.001). Installing non-polluting, more effective heating in the homes of children with asthma did not significantly improve lung function but did significantly reduce symptoms of asthma, days off school, healthcare utilisation, and visits to a pharmacist. Clinical Trials NCT00489762.

Indoor Nitrogen Dioxide Exposure and Children’s Pulmonary Function

Article

Full-text available

Oct 1990
J AIR WASTE MANAGE

Elevated concentrations of nitrogen dioxide (NO2) are produced in the home by the use of unvented gas appliances. In studies on potential health effects of indoor exposure to NO2, exposure has mostly been estimated from the presence or absence of sources like gas cookers in the home. This leads to misclassification of exposure, as NO2 concentrations in the home depend also on source use, ventilation habits, time budgets, etc. The availability of cheap, passive monitoring devices has made it possible to measure indoor concentrations of NO2 directly in health effects studies, albeit with averaging times of one to several days. So far, it has not been evaluated whether this increases the sensitivity of a study to detect health effects of NO2. In this paper, a comparison is made between NO2 sources and weekly average indoor NO2 measurements, as predictors of pulmonary function in a study among children aged 6-12 years. The relationship between exposure and lung functions was found to be generally non-significant in this study. The results further suggested that in this study, measuring indoor NO2 concentrations with passive monitors offered no advantage over the simple use of source presence as exposure variable.

Respiratory Health Effects of the Indoor Environment in a Population of Dutch Children

Article

Full-text available

Dec 1990
Am J Respir Crit Care Med

The effect of indoor exposure to nitrogen dioxide on respiratory health was studied over a period of 2 yr in a population of nonsmoking Dutch children 6 to 12 yr of age. Lung function was measured at the schools, and information on respiratory symptoms was collected from a self-administered questionnaire completed by the parents of the children. Nitrogen dioxide was measured in the homes of all children with Palmes' diffusion tubes. In addition, information on smoking and dampness in the home was collected by questionnaire. There was no relationship between exposure to nitrogen dioxide in the home and respiratory symptoms. Respiratory symptoms were found to be associated with exposure to tobacco smoke and home dampness. There was a weak, negative association between maximal midexpiratory flow (MMEF) and exposure to nitrogen dioxide. FEV1, peak expiratory flow, and MMEF were all negatively associated with exposure to tobacco smoke. Home dampness was not associated with pulmonary function. Lung function growth, measured over a period of 2 yr, was not consistently associated with any of the indoor exposure variables. The development of respiratory symptoms over time was not associated with indoor exposure to nitrogen dioxide. There was a significant association between exposure to environmental tobacco smoke in the home and the development of wheeze. There was also a significant association between home dampness and the development of cough.

Relationship of Parental Smoking and Gas Cooking to Respiratory Disease in Children

Article

Full-text available

Jan 1984

In a survey of 1,355 children six- to 12 years of age, the risk of hospitalization for respiratory illness among children before age two years was increased when gas was used for cooking at home (p less than 0.001) or at least one of the parents smoked (p less than 0.02). The occurrence of cough with colds in children also was significantly increased when one or both parents smoked (p less than 0.001). Small but significant increases (p less than .05) in the mean values of forced expiratory volume at one second, the flow rate at 75 percent of the forced vital capacity, and the forced expiratory flow rate from 25 percent to 75 percent of the vital capacity (FEF25-75) were seen after administering inhaled isoproterenol to children whose parents smoked (n = 94) but not among children whose parents did not smoke (n = 89); this was not seen in association with gas cooking. Thus, exposure of children during the first two years of life to gas cooking or cigarette smoking appears to be associated with an increased risk of hospitalization for respiratory illness, and cigarette smoking appears to be associated with a more consistent response to inhaled bronchodilator among six- to 12-year-old children with no other history of chronic respiratory illness.

Measuring inconsistency in meta-analysis

Article

Jan 2003

Indoor environmental risk factors for respiratory health in children

Article

Jan 1998
INDOOR AIR

M.H. Garrett

The indoor environment of 80 houses in the Latrobe Valley, Victoria, Australia was assessed during six visits performed bi-monthly over a period of one year. Children between 7 and 14 years of age residing in the houses were included, resulting in 148 study children, 53 of whom were asthmatic. A respiratory health questionnaire was completed and skin prick tests performed. Significant risk factors for asthma were: exposure to a gas stove (OR=3.15, 95% CI 1.28-7.72), and indoor pets (OR= 2.68, 95% CI 1.07-6.70). Exposure to airborne Aspergillus spores (+10 CFU/m3, OR=1.51, 95% CI 1.05-2.18) was a risk factor for atopy, while exposure to a gas stove (OR=2.32, 95% CI 1.04-5.18) was a risk factor for respiratory symptoms. In conclusion, exposure to gas stoves, fungal spores and pets in the home were identified as statistically significant risk factors for respiratory health in children.

Effects of volatile organic compounds, damp, and other environmental exposures in the home on wheezing illness in children

Article

Nov 2003

A J Venn

Background The effects of indoor exposure to volatile organic compounds (VOCs), including formaldehyde, on respiratory health are not clearly understood. The aim of this study was to determine the independent effects of VOCs and other common environmental exposures in the home on the risk and severity of persistent wheezing illness in children. Methods Total volatile organic compounds, formaldehyde, nitrogen dioxide, damp (on a four category scale of % wood moisture equivalent), and environmental tobacco smoke (from salivary cotinine) were measured objectively in the homes of 193 children with persistent wheezing illness and 223 controls aged 9–11 years in Nottingham, UK. Results The risk of wheezing illness was significantly increased only in relation to damp (odds ratio (OR) per increasing category=1.32 (95% confidence interval (CI), 1.00 to 1.75)), and was unrelated to the other exposures measured. Among cases, formaldehyde and damp were associated with more frequent nocturnal symptoms (OR per increasing quartile and category, respectively, 1.45 (1.06 to 1.98) and 1.97 (1.10 to 3.53)), significantly more so in atopic cases, but there was no effect of total volatile organic compounds, nitrogen dioxide, or cotinine. Conclusions Domestic volatile organic compounds are not a major determinant of risk or severity of childhood wheezing illness, though formaldehyde may increase symptom severity. Indoor damp increases both the risk and severity of childhood wheezing illness.

Respiratory health effects of nitrogen dioxide exposure and current guidelines

Article

Mar 1999

This article reviews (i) the role of nitrogen dioxide (NO2) in respiratory diseases, including asthma, and (ii) appraises whether current guidelines for NO2 confer an adequate margin of safety for asthmatics. Medline and Excerpta Medica (1966-1997) were searched to retrieve original epidemiological studies which examined the relationship between NO2 and respiratory diseases including asthma. Previously reported reviews of controlled clinical studies were also utilised. The results of this search were then related to current NO2 guidelines. The review of 23 outdoor and 36 indoor studies suggests that respiratory effects are associated with levels of NO2 that may be encountered in common domestic and outdoor settings. Meta-analyses of studies among the general population of children demonstrate a 20% increase in respiratory problems, including increases of asthma by 20%, and wheezing by 12% in households with gas cookers. Epidemiological evidence also indicates that hourly NO2 values of 80 ppb are likely to cause respiratory symptoms in the general population of children. Such levels are frequently present in domestic and school settings. Critical appraisal of the epidemiological evidence indicates the need for a revision of NO2 guidelines to protect both asthmatics and the general population, especially children.

Cooking fuels and prevalence of asthma: A global analysis of phase three of the International Study of Asthma and Allergies in Childhood (ISAAC)

Article

Jul 2013

Indoor air pollution from a range of household cooking fuels has been implicated in the development and exacerbation of respiratory diseases. In both rich and poor countries, the effects of cooking fuels on asthma and allergies in childhood are unclear. We investigated the association between asthma and the use of a range of cooking fuels around the world. For phase three of the International Study of Asthma and Allergies in Childhood (ISAAC), written questionnaires were self-completed at school by secondary school students aged 13-14 years, 244 734 (78%) of whom were then shown a video questionnaire on wheezing symptoms. Parents of children aged 6-7 years completed the written questionnaire at home. We investigated the association between types of cooking fuels and symptoms of asthma using logistic regression. Adjustments were made for sex, region of the world, language, gross national income, maternal education, parental smoking, and six other subject-specific covariates. The ISAAC study is now closed, but researchers can continue to use the instruments for further research. Data were collected between 1999 and 2004. 512 707 primary and secondary school children from 108 centres in 47 countries were included in the analysis. The use of an open fire for cooking was associated with an increased risk of symptoms of asthma and reported asthma in both children aged 6-7 years (odds ratio [OR] for wheeze in the past year, 1·78, 95% CI 1·51-2·10) and those aged 13-14 years (OR 1·20, 95% CI 1·06-1·37). In the final multivariate analyses, ORs for wheeze in the past year and the use of solely an open fire for cooking were 2·17 (95% CI 1·64-2·87) for children aged 6-7 years and 1·35 (1·11-1·64) for children aged 13-14 years. Odds ratios for wheeze in the past year and the use of open fire in combination with other fuels for cooking were 1·51 (1·25-1·81 for children aged 6-7 years and 1·35 (1·15-1·58) for those aged 13-14 years. In both age groups, we detected no evidence of an association between the use of gas as a cooking fuel and either asthma symptoms or asthma diagnosis. The use of open fires for cooking is associated with an increased risk of symptoms of asthma and of asthma diagnosis in children. Because a large percentage of the world population uses open fires for cooking, this method of cooking might be an important modifiable risk factor if the association is proven to be causal. BUPA Foundation, the Auckland Medical Research Foundation, the Health Research Council of New Zealand, the Asthma and Respiratory Foundation of New Zealand, the Child Health Research Foundation, the Hawke's Bay Medical Research Foundation, the Waikato Medical Research Foundation, Glaxo Wellcome New Zealand, the NZ Lottery Board, Astra Zeneca New Zealand, Hong Kong Research Grant Council, Glaxo Wellcome International Medical Affairs.

Risk Factors Indoors and Prevalences of Childhood Respiratory Health in Four Countries in Western and Central Europe

Article

Dec 1998

Abstract The prevalence of respiratory symptoms and risk factors were gathered in four study centres in Western and Central Europe as part of an EU-funded multi-centre study addressing the use of small area methods in air pollution epidemiology (SAVI-AH). The study was carried out in Prague (CZ), Poznan (PL), Huddersfield (UK) and Amsterdam (NL). Prevalences of respiratory symptoms and risk factors between the centres were compared, and associations between risk factors and respiratory symptoms were calculated. Respiratory health was assessed by a self-administered questionnaire, distributed among parents or guardians of schoolchildren between the age of 7 and 11 years. Life-time wheezing and attacks of shortness of breath showed highest prevalences in Huddersfield (30% and 14%, respectively); usual cough showed highest prevalence in Poznan (27%). Differences in prevalence between the centres were found for the potential determinants “age” (due to different age ranges), “gas cooking” (highest in Amsterdam and Poznan), gas/coal heating (lowest in Central European centres), home dampness (highest in Western European centres), disturbance by traffic (highest in urban centres), maternal smoking (highest in Central European centres), family history (highest in Huddersfield) and education (highest in Huddersfield). The prevalence of pets in the home differed only slightly between the study centres. Of the potential deteminants studied, gender, family history of allergic diseases, dampness of the home and, to a lesser extent, passive smoking were important risk factors for life-time prevalence of respiratory symptoms in schoolchildren.

Household Levels of Nitrogen Dioxide and Pediatric Asthma Severity

Article

Jan 2013

Background: Adverse respiratory effects in children with asthma are associated with exposures to nitrogen dioxide (NO2). Levels indoors can be much higher than outdoors. Primary indoor sources of NO2 are gas stoves, which are used for cooking by one-third of U.S. households. We investigated the effects of indoor NO2 exposure on asthma severity among an ethnically and economically diverse sample of children, controlling for season and indoor allergen exposure. Methods: Children 5-10 years of age with active asthma (n = 1,342) were recruited through schools in urban and suburban Connecticut and Massachusetts (2006-2009) for a prospective, year-long study with seasonal measurements of NO2 and asthma severity. Exposure to NO2 was measured passively for four, month-long, periods with Palmes tubes. Asthma morbidity was concurrently measured by a severity score and frequency of wheeze, night symptoms, and use of rescue medication. We used adjusted, hierarchical ordered logistic regression models to examine associations between household NO2 exposure and health outcomes. Results: Every 5-fold increase in NO2 exposure above a threshold of 6 ppb was associated with a dose-dependent increase in risk of higher asthma severity score (odds ratio = 1.37 [95% confidence interval = 1.01-1.89]), wheeze (1.49 [1.09-2.03]), night symptoms (1.52 [1.16-2.00]), and rescue medication use (1.78 [1.33-2.38]). Conclusions: Asthmatic children exposed to NO2 indoors, at levels well below the U.S. Environmental Protection Agency outdoor standard (53 ppb), are at risk for increased asthma morbidity. Risks are not confined to inner city children, but occur at NO2 concentrations common in urban and suburban homes.

Gas cooking, Respiratory and allergic outcomes in the PIAMA birth cohort study

Article

Dec 2012
OCCUP ENVIRON MED

Objectives: Evidence for a relationship between gas cooking and childhood respiratory health is inconsistent and few longitudinal studies have been reported. Our aim was to examine the association between gas cooking and the development of respiratory and allergic outcomes longitudinally in a prospective birth cohort study. Methods: The Prevention and Incidence of Asthma and Mite Allergy birth cohort study followed children from birth (1996/1997) until age 8. Annual questionnaires were used to document respiratory and allergic symptoms. Allergic sensitisation and bronchial hyper-responsiveness (BHR) were measured at age 8 in subpopulations. A total of 3590 children were included in the present analysis. We used generalised estimating equations and discrete-time hazard models to study the overall and age-specific associations between exposure to gas cooking and the risk of developing respiratory illnesses. Sensitivity analyses of intermittent, always, current and early exposure to gas cooking were conducted. Results: Ever gas cooking exposure was associated with nasal symptoms (sneezing, runny/blocked nose without a cold) during the first 8 years of life (OR=1.32, 95% CI 1.09 to 1.59), but not with lower respiratory tract infections, eczema, allergic sensitisation and BHR. Associations with nasal symptoms were similar among children with intermittent, always, current and early exposure. Among girls only, prevalent asthma was associated with ever gas cooking (OR=1.97, 95% CI 1.05 to 3.72). Conclusions: Overall, our findings provide little evidence for an adverse effect of exposure to gas cooking on the development of asthma and allergies.

Outdoor Air Concentrations of Nitrogen Dioxide and Sulfur Dioxide and Prevalence of Wheezing in School Children

Article

Mar 2000
EPIDEMIOLOGY

We report analysis of data on outdoor air pollution and respiratory symptoms in children collected in the Czech part of the international Small Area Variations in Air pollution and Health (SAVIAH) Project, a methodological study designed to test the use of geographical information systems (GIS) in studies of environmental exposures and health at small area level. We collected the following data in two districts of Prague: (1) individual data on 3,680 children (response rate 88%) by questionnaires; (2) census-based socio-demographic data for small geographical units; (3) concentrations of nitrogen dioxide (NO2) and sulfur dioxide (SO2) measured by passive samplers in three 2-week surveys at 80 and 50 locations, respectively. We integrated all data into a geographical information system. Modeling of NO2 and SO2 allowed estimation of exposure to outdoor NO2 and SO2 at school and at home for each child. We examined the associations between air pollution and prevalence of wheezing or whistling in the chest in the last 12 months by logistic regression at individual level, weighted least squares regression at small area (ecological) level and multilevel modeling. The results varied by the level of analysis and method of exposure estimation. In multilevel analyses using individual data, odds ratios per 10 μg/m3 increase in concentrations were 1.16 (95% CI = 0.95-1.42) for NO2, and 1.08 (95% CI = 0.97-1.21) for SO2. While mapping of spatial distribution of NO2 and SO2 in the study area appeared valid, the interpolation from outdoor to personal exposures requires consideration.

Review of the epidemiological evidence on health effects of nitrogen dioxide exposure from gas stoves

Article

Oct 1999
J Environ Med

This review addresses the evidence on the health effects of exposure to emissions of NO² from gas stoves, covering findings of 45 epidemiological studies. These studies had addressed diverse outcome measures, including the risks of acute respiratory illness, decreased pulmonary function, respiratory symptoms and asthma exacerbation. Although most studies have focused on schoolchildren, studies of adults and more recently, prospective studies of infants have also been carried out. The findings have not been consistent across all studies in showing adverse effects. We conclude that the evidence does not support a causal relationship between exposure NO² or use of a gas stove and increased risk for respiratory morbidity at the levels of NO2 typically associated with gas stoves. Some studies do show increased risk for respiratory health effects, however, and the evidence does not support the conclusion that NO2 emitted by gas stoves is risk-free. Further research would be indicated if populations receiving exposures in a range of interest can be identified. Copyright © 1999 John Wiley & Sons, Ltd.

Indoor Environmental Risk Factors for Respiratory Health in Children

Article

Apr 2004
INDOOR AIR

Abstract The indoor environment of 80 houses in the Latrobe Valley, Victoria, Australia was assessed during six visits performed bi-monthly over a period of one year. Children between 7 and 14 years of age residing in the houses were included, resulting in 148 study children, 53 of whom were asthmatic. A respiratory health questionnaire was completed and skin prick tests performed. Significant risk factors for asthma were: exposure to a gas stove (OR=3.15, 95% CI 1.28-7.72), and indoor pets (OR = 2.68, 95% CI 1.07-6.70). Exposure to airborne Aspergillus spores (+10 CFU/m3, OR=1.51, 95% CI 1.05-2.18) was a risk factor for atopy, while exposure to a gas stove (OR=2.32, 95% CI 1.04-5.18) was a risk factor for respiratory symptoms. In conclusion, exposure to gas stoves, fungal spores and pets in the home were identified as statistically significant risk factors for respiratory health in children.

Farrow A, Greenwood R, Preece S, Golding J. Nitrogen dioxide, the oxides of nitrogen, and infants' health symptoms. ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood. Arch Environ Health. 1997 May-Jun;52(3):189-94.

Article

May 1997
Arch Environ Health

Indoor Risk Factors for Asthma in a Prospective Study of Adolescents

Article

May 2002
EPIDEMIOLOGY

The risk of asthma associated with pets and other indoor exposures has been examined in both cross-sectional and prospective studies of younger children. However, there has been little investigation of the effect of the indoor environment on incident asthma in adolescents. Risk factors for the development of asthma were examined in a cohort of 3535 Southern California school children with no history of asthma at 1993 entry into the study, who were followed for up to 5 years. Newly diagnosed cases of asthma were identified by yearly interview report. A total of 265 children reported a new diagnosis of asthma during the follow-up period; 163 of these had reported no history of wheeze at baseline. The risk associated with indoor exposures assessed by questionnaire at entry into the study was examined using Cox proportional hazards models. In children with no history of wheezing, an increased risk of developing asthma was associated with a humidifier (relative risk [RR] = 1.7; 95% confidence interval [CI] = 1.2-2.4), any pet (RR = 1.6; 95% CI = 1.0-2.5), or specifically a dog (RR = 1.4; 95% CI = 1.0-2.0) in the home. An estimated 32% of new asthma cases could be attributed to pets. We conclude that furry pets are a common and potentially remediable risk factor for new onset asthma in adolescents. Our results suggest that a humidifier in the home may contribute to the onset of asthma in this age group.

Association of gas cooking with children's respiratory health: Results from GINIplus and LISAplus birth cohort studies

Article

Apr 2012
INDOOR AIR

Abstract Previous studies have found inconsistent results on the association between asthma in children and gas cooking emissions. We aimed to assess the effects of the long-term exposure to gas cooking on the onset of asthma and respiratory symptoms, focusing on wheezing, in children from two German birth cohorts: LISAplus and GINIplus. A total of 5078 children were followed until the age of 10 years. Asthma, wheezing, gas cooking, and exposure to other indoor factors were assessed through parental reported questionnaires administered periodically. Logistic and multinomial regressions adjusting for potential confounders were performed. The prevalence of asthma and persistent wheezing was higher among children exposed to gas cooking but the results were not statistically significant. Exposure to gas cooking was positively associated (P-value < 0.05) with exposure to other indoor factors (dampness, environmental tobacco smoke, and pets). Our results did not show a statistically significant association between the exposure to gas cooking and children’s respiratory health. These analyses are consistent with the assumption of no effect of the exposure to low doses of nitrogen dioxide. The strong positive associations found between gas cooking and other indoor factors highlight the importance of considering other indoor factors when assessing health effects of gas cooking. Low-dose exposure to indoor nitrogen dioxide through gas cooking might not contribute to increase the risk of asthma and respiratory symptoms in children.

Outdoor, but not indoor, nitrogen dioxide exposure is associated with persistent cough during the first year of life

Article

Sep 2011

Because their lungs and immune system are not completely developed, children are more susceptible to respiratory disease and more vulnerable to ambient pollution. We assessed the relation between prenatal and postnatal nitrogen dioxide (NO(2)) levels and the development of lower respiratory tract infections (LRTI), wheezing and persistent cough during the first year of life. The study population consisted of 352 children from a birth cohort in Valencia, Spain. Prenatal exposure to NO(2), a marker of traffic related air pollution was measured at 93 sampling sites spread over the study area during four different sampling periods of 7 days each. It was modeled for each residential address through land use regression using the empirical measurements and data from geographic information systems. Postnatal exposure was measured once inside and outside each home using passive samplers for a period of 14 days. Outcomes studied were any episode of LRTI during the child's first year of life diagnosed by a doctor (bronchitis, bronchiolitis or pneumonia), wheezing (defined as whistling sounds coming from the chest), and persistent cough (more than three consecutive weeks). Outcomes and potential confounders were obtained from structured questionnaires. Multiple logistic regression was used to identify associations. The cumulative incidence (CI) at first year of life was 30.4% for LRTI (23.0% bronchiolitis, 11.9% bronchitis and 1.4% pneumonia), 26.1% for wheezing and 6.3% for persistent cough. The adjusted odds ratio (95% confidence interval) per 10μg/m(3) increment in postnatal outdoor NO(2) concentration was 1.40 (1.02-1.92) for persistent cough. We also found some pattern of association with LRTI, bronchiolitis, bronchitis, wheezing and persistent cough in different prenatal periods, although it was not statistically significant. Our results indicate that exposure to outdoor, but not indoor, NO(2) during the first year of life increases the risk of persistent cough.

Influence of indoor factor in dwellings on the development of childhood asthma

Article

Jan 2011

Joachim Heinrich

Asthma has become the most common, childhood chronic disease in the industrialized world, and it is also increasing in developing regions. There are huge differences in the prevalence of childhood asthma across countries and continents, and there is no doubt that the prevalence of asthma was strongly increasing during the past decades worldwide. Asthma, as a complex disease, has a broad spectrum of potential determinants ranging from genetics to life style and environmental factors. Environmental factors are likely to be important in explaining the regional differences and the overall increasing trend towards asthma's prevalence. Among the environmental conditions, indoor factors are of particular interest because people spend more than 80% of their time indoors globally. Increasing prices for oil, gas and other sources of primary energy will further lead to better insulation of homes, and ultimately to reduced energy costs. This will decrease air exchange rates and will lower the dilution of indoor air mass with ambient air. Indoor air quality and potential health effects will therefore be an area for future research and for gaining a better understanding of asthma epidemics. This strategic review will summarize the current knowledge of the effects of a broad spectrum of indoor factors on the development of asthma in childhood in Western countries based on epidemiological studies. In conclusion, several epidemiological studies point out, that indoor factors might cause asthma in childhood. Stronger and more consistent findings are seen when exposure to these indoor factors is assessed by surrogates for the source of the actual toxicants. Measurement-based exposure assessments for several indoor factors are less common than using surrogates of the exposure. These studies, however, mainly showed heterogeneous results. The most consistent finding for an induction of asthma in childhood is related to exposure to environmental tobacco smoke, to living in homes close to busy roads, and in damp homes where are visible moulds at home. The causing agents of the increased risk of living in damp homes remained uncertain and needs clarification. Exposure to pet-derived allergens and house dust mites are very commonly investigated and thought to be related to asthma onset. The epidemiological evidence is not sufficient to recommend avoidance measures against pet and dust mites as preventive activities against allergies. More research is also needed to clarify the potential risk for exposure to volatile and semi-volatile organic compounds due to renovation activities, phthalates and chlorine chemicals due to cleaning.

Indoor air pollution and childhood asthma: Variations between urban and rural areas

Article

Dec 2010
INDOOR AIR

Unlabelled: Health effects of indoor pollution have been investigated overall in urban areas. To compare the potential effect of home air pollutants on asthma in urban and rural houses, two case-control populations, composed of children living in the city (32 asthmatics and 31 controls) and in the countryside (24 asthmatics and 27 controls) were included. During 1 week, nitrogen dioxide, fine particles, and volatile organic compounds (formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, and xylenes) were assessed at home. Urban dwellings were found to be more polluted than rural ones, with concentrations up to two times higher. In the whole population, exposure to acetaldehyde and toluene was significantly associated with a higher risk of asthma. In the urban population, the association with toluene was significant in children studied during winter, and with toluene, xylenes, and ethylbenzene when cases were restricted to current asthmatics. In rural settings, a relationship between asthma and formaldehyde exposure was observed (OR = 10.7; 95% CI 1.69-67.61). Our findings suggest that daily continuous exposures to pollutants may be implicated in asthma, even in the case of low exposure, as those found in rural areas. Our results could also indicate a specific effect of indoor pollution in the rural environment. Practical implications: Everyday exposure to indoor pollution was associated with a higher risk of childhood asthma. These findings suggest that even at low concentrations, pollutants could be implicated in asthma and reinforce the importance of establishing guideline values to improve indoor air quality by limiting sources or by optimizing ventilation. Specific effects could occur in rural environments where pollution differs from urban area.

Gas cooking is associated with small reductions in lung function in children

Article

Aug 2010
EUR RESPIR J

Inconsistent effects of gas cooking on lung function have been reported. In a previous study from Austria, we demonstrated a significant, though small, reduction of lung function parameters in children living in homes with gas stoves. We used a larger international database to check if this finding can be generalised. To study the relative impact of cooking with gas on lung function parameters of primary school children in a wide range of geographical settings, we analysed flow and volume data of approximately 24,000 children (aged 6-12 yrs) from nine countries in Europe and North America. Exposure information was obtained by comparable questionnaires and spirometry according to an American Thoracic Society/European Respiratory Society protocol. Linear regressions were used, controlling for individual risk factors and study area. Heterogeneity between study-specific results and mean effects were estimated using meta-analytical tools. On average, gas cooking reduced lung function parameters. Overall effects were small (-0.1-0.7%) and only significant for forced vital capacity and forced expiratory volume in 1 s. There was some indication that allergic children were more affected by gas cooking. Under current housing conditions, gas cooking is associated with only small reductions in lung function.

Long-term exposure to indoor air pollution and wheezing symptoms in infants

Article

Oct 2009
INDOOR AIR

Long-term exposure to air pollution is suspected to cause recurrent wheeze in infants. The few previous studies have had ambiguous results. The objective of this study was to estimate the impact of measured long-term exposure to indoor air pollution on wheezing symptoms in infants. We monitored wheezing symptoms in diaries for a birth cohort of 411 infants. We measured long-term exposure to nitrogen oxides (NO(x)), NO(2), formaldehyde, PM(2.5) and black smoke in the infants' bedrooms and analyzed risk associations during the first 18 months of life by logistic regression with the dichotomous end-point 'any symptom-day' (yes/no) and by standard linear regression with the end-point 'number of symptom-days'. The results showed no systematic association between risk for wheezing symptoms and the levels of these air pollutants with various indoor and outdoor sources. In conclusion, we found no evidence of an association between long-term exposure to indoor air pollution and wheezing symptoms in infants, suggesting that indoor air pollution is not causally related to the underlying disease. Practical Implications Nitrogen oxides, formaldehyde and fine particles were measured in the air in infants' bedrooms. The results showed no evidence of an association between long-term exposure and wheezing symptoms in the COPSAC birth cohort.

Indoor nitrogen dioxide exposure and children's pulmonary function.

Article

Predicting the long-term prognosis of children with symptoms suggestive of asthma at preschool age

Article

Sep 2009

Clinicians have difficulty in diagnosing asthma in preschool children with suggestive symptoms. We sought to develop a clinical asthma prediction score for preschool children who have asthma-like symptoms for the first time. The Prevalence and Incidence of Asthma and Mite Allergy birth cohort followed 3,963 children for 8 years. Between 0 and 4 years of age, 2,171 (55%) children reported "wheezing," "coughing at night without a cold," or both. In these children possible predictor variables for asthma were assessed at the age respiratory symptoms were first reported. Asthma was defined as wheezing, inhaled steroid prescription, or a doctor's diagnosis of asthma at both age 7 and 8 years of age. Eleven percent of children with symptoms at 0 to 4 years of age had asthma at 7 to 8 years of age. Eight clinical parameters independently predicted asthma at 7 to 8 years of age: male sex, postterm delivery, parental education and inhaled medication, wheezing frequency, wheeze/dyspnea apart from colds, respiratory infections, and eczema. In 72% of the cases, the model accurately discriminated between asthmatic and nonasthmatic children. A clinical risk score was developed (range, 0-55 points). Symptomatic children with a score of less than 10 points had a 3% risk, whereas children with a score of 30 points or greater had a 42% risk of asthma. A risk score based on 8 readily available clinical parameters at the time preschool children first reported asthma-like symptoms predicted the risk of asthma at 7 to 8 years of age.

Cross-sectional survey of risk factors for asthma in 6-7-year-old children in New Zealand: International Study of Asthma and Allergy in Childhood Phase Three

Article

Jun 2009
J Paediatr Child Health

To identify risk factors for asthma in primary school-aged children in New Zealand. A cross-sectional survey of 10,873 6-7-year-old children in Auckland, Bay of Plenty, Nelson and Christchurch (a response rate of 85.2%). A questionnaire was completed by the parent or care giver. 22.2% of children wheezed in the last 12 months (current wheeze). Maori children were at greater risk of current wheeze compared with European children (adjusted odds ratio (adjOR) = 1.37; 95% confidence interval = 1.18-1.59). Antibiotics and paracetamol used in the first year of life were associated with an increased risk of current wheeze (adjOR = 1.78 (1.56-2.04) and adjOR = 1.31 (1.06-1.61), respectively). Watching television for 5 or more hours per day was associated with an increased risk of current wheeze (adjOR = 1.44 (1.13-1.83)). Milk and egg consumption in the last 12 months was associated with a reduced risk of current wheeze. This study has identified risk factors for asthma in children aged 6-7 years, although causal pathways cannot be established. These associations have important public health implications if causal.

Levels of Pollutants in Indoor Air and Respiratory Health in Preschool Children: A Systematic Review

Article

Mar 2009
PEDIATR PULM

The aim of this paper is thus to identify, evaluate, and summarize in a systematic fashion all the epidemiological studies that have analyzed the association between exposure to specific indoor air pollutants and respiratory disease among children under the age of five. A search was carried out in the main biomedical bibliographic sources in December 2006 and updated in February 2008. The study period covered 12 years (1996-2007). All the selected papers were carefully read. We focused on studies that analyzed at least one indicator of respiratory health and which included one or more indoor air pollutants in relation to the respiratory health of children under the age of 5. Studies that analyzed passive smoking as the sole source of indoor air pollution were not included. Fourteen studies were considered to be relevant. The most analyzed pollutant was nitrogen dioxide, followed by volatile organic compounds, airborne particulates and other pollutants; phthalates and CO(2). The literature reviewed within our criteria seems to indicate that several indoor pollutants, even at the moderate levels found in the developed countries, could be harmful to the respiratory health of very young children. Future research should focus on conducting more studies, preferably making use of cohorts, with adequate techniques for measuring indoor pollution levels.

Association between gas cooking and respiratory disease in children

Article

Aug 1977

A four-year longitudinal study of the prevalence of respiratory symptoms and disease in schoolchildren and related environmental and socio-economic factors is in progress. We report results for the first year of this study (1973). A total of 5758 children aged 6 to 11 years from 28 randomly selected areas of England and Scotland were examined. In an analysis of the effects on health of possible indoor pollutants, boys and girls from homes in which gas was used for cooking were found to have more cough, "colds going to the chest", and bronchitis than children from homes where electricity was used. The girls also had more wheeze if their families used gas for cooking. This "cooking effect" appeared to be independent of the effects of age, social class, latitude, population density, family size, overcrowding, outdoor levels of smoke and sulphur dioxide and types of fuel used for heating. It was concluded that elevated levels of oxides of nitrogen arising from the combustion of gas might be the cause of the increased respiratory illness.

Meta-analysis of the effects of indoor nitrogen dioxide and gas cooking on asthma and wheeze in children

Abstract

No full-text available