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Impact of Pollen on Human Health: More Than Allergen Carriers?
Abstract
The transfer of pollen from floral anther to recipient stigma is the critical reproductive event among higher plants--this is the botanical view of pollen. Proteins and glycoproteins from pollen can function as allergens, environmental molecules interacting with the human immune system to elicit an allergic response in susceptible individuals--this is how allergists and immunologists see pollen grains. Between 10 and 25% of the population now have symptoms of hay fever or allergic asthma and the incidence has more than doubled in the past three decades while the reason(s) for this increment are only hypothetical, but there is a multitude of them. Despite our natural focus on this impact of pollen on human health, pollen have to be considered in a larger context. First of all, to evaluate the bioavailability of allergens from pollen, we have to understand their function and their influence factors. Furthermore, pollen grains are not only releasing proteins eliciting specific immune responses, but they also liberate bioactive lipid mediators and this much more rapidly. And last but not least, recent observations indicate, that pollen do not only induce allergy and thus have a much broader impact on human health. This review is an attempt to favour this holistic view of pollen and their impact on human health.
... 1,44 Air pollutants adhere to the surface of pollen grains and paucimicronic-sized plant particles and change not only the morphology of these antigen-bearing agents but also their allergenic potential. 59 In addition, by producing airway inflammation increases the permeability of this pathway and pollutants overcome the mucosal barrier and could be responsible for enhancing the responses of pollinosis induced by allergens in atopic patients. [57][58][59] Published data suggest an increasing effect of aeroallergens in allergic patients, which generates a higher probability of developing an allergic respiratory disease in sensitized patients and an exacerbation in patients who are already symptomatic. ...
... 59 In addition, by producing airway inflammation increases the permeability of this pathway and pollutants overcome the mucosal barrier and could be responsible for enhancing the responses of pollinosis induced by allergens in atopic patients. [57][58][59] Published data suggest an increasing effect of aeroallergens in allergic patients, which generates a higher probability of developing an allergic respiratory disease in sensitized patients and an exacerbation in patients who are already symptomatic. 59 ...
... [57][58][59] Published data suggest an increasing effect of aeroallergens in allergic patients, which generates a higher probability of developing an allergic respiratory disease in sensitized patients and an exacerbation in patients who are already symptomatic. 59 ...
... Air pollutants adhere to the surface of pollen grains and paucimicronic-sized plant particles and change not only the morphology of these antigen-bearing agents, but also their allergenic potential (60). In addition, by producing airway inflammation increases the permeability of this pathway and pollutants overcome the mucosal barrier and could be responsible for enhancing the responses of pollinosis induced by allergens in atopic patients (58)(59)(60). ...
... Air pollutants adhere to the surface of pollen grains and paucimicronic-sized plant particles and change not only the morphology of these antigen-bearing agents, but also their allergenic potential (60). In addition, by producing airway inflammation increases the permeability of this pathway and pollutants overcome the mucosal barrier and could be responsible for enhancing the responses of pollinosis induced by allergens in atopic patients (58)(59)(60). ...
... Published data suggest an increasing effect of aeroallergens in allergic patients, which generates a higher probability of developing an allergic respiratory disease in sensitized patients and an exacerbation in patients who are already symptomatic (60)(61)(62)(63)(64)(65)(66)(67). ...
The impact of climate change on the environment, biosphere and biodiversity has become more evident in the recent years. Human activities have increased atmospheric concentrations of carbon dioxide (CO2) and other greenhouse gases. Change in climate and the correlated global warming affects the quantity, intensity and frequency of precipitation type as well as the frequency of extreme events such as heat waves, droughts, thunderstorms, floods and hurricanes. Respiratory health can be particularly affected by climate change, which contributes to the development of allergic respiratory diseasesand asthma. Pollen and mold allergens are able to trigger the release of pro‐inflammatory and immunomodulatory mediators that accelerate the onset the IgE‐mediated sensitizationand of allergy. Allergy to pollen and pollen season at its beginning, in duration and intensity are altered by climatechange. Studies showed that plants exhibit enhanced photosynthesis and reproductive effects and produce more pollen as a response to high atmospheric levels of carbon dioxide (CO2).Molds which proliferation is increased by floods and rainy storms are responsible for severe asthma. Pollen and mold allergy is generally used to evaluate the interrelation between air pollution and allergic respiratory diseases, such as rhinitis and asthma. Thunderstorms during pollen seasons can cause exacerbation of respiratory allergy and asthma in patients with hay fever. A similar phenomenon is observed for molds.Measures to reduce greenhouse gas emissions can have positive health benefits.
... Pollen is a complex mixture of allergenic proteins and other nonallergenic products [49]. Some of these substances are lipids that exhibit strong cross-reactivity with leukotriene B4 and prostaglandin E2; such eicosanoids act as allergen-independent proinflammatory factors that contribute to allergic inflammation [50]. Moreover, their enzymes can produce reactive oxygen species [51]. ...
... Moreover, their enzymes can produce reactive oxygen species [51]. Grains of pollen are too large to access the bronchi, except when exposed to an osmotic rupture or environmental degradation [50], which release submicronic respirable allergens that are integrated into particles smaller than 5-8 µm, becoming bioaerosols with a significant allergenic load [52]. Such subpollen particles remain airborne for a longer time, may go undetected via traditional detection methods, and can reach the bronchi, inducing bronchial constriction [52], especially if physical exercise and/or oral respiration are performed. ...
Asthma is a heterogeneous and very complex group of diseases, and includes different clinical phenotypes depending on symptoms, progression, exacerbation patterns, or responses to treatment, among other characteristics. The allergic phenotype is the most frequent, especially in pediatric asthma. It is characterized by sensitization (the production of specific IgEs) to allergens and frequent comorbidity with rhinitis as well as atopic dermatitis. Given the complexity of allergic asthma, knowledge of it must be approached from different points of view: clinical, histological, physiological, epidemiological, biochemical, and immunological, among others. Since partial approaches do not allow for the understanding of this complexity, it is necessary to have multidimensional knowledge that helps in performing the optimal management of each case, avoiding a “blind men and elephant parable” approach. Allergens are antigens that trigger the production of specific IgE antibodies in susceptible individuals, who present symptoms that will depend on the type and intensity of the allergenic load as well as the tissue where the interaction occurs. Airborne allergens cause their effects in the respiratory tract and eyes, and can be indoor or outdoor, perennial, or seasonal. Although allergens such as mites, pollens, or animal dander are generally considered single particles, it is important to note that they contain different molecules which could trigger distinct specific IgE molecules in different patients. General practitioners, pediatricians, and other physicians typically diagnose and treat asthma based on clinical and pulmonary function data in their daily practice. This nonsystematic and nonexhaustive revision aims to update other topics, especially those focused on airborne allergens, helping the diagnostic and therapeutic processes of allergic asthma and rhinitis.
... it can affect people who have never been diagnosed with asthma. Those at increased risk of thunderstorm asthma include people with a history of asthma, people with undiagnosed asthma and people with hay fever (particularly seasonal hay fever) or allergy to grass pollen [32]. ...
... The main risk factor appears to be a history of allergic rhinitis or sensitization to a particular allergen, circulating load of triggering aeroallergens, and age between 20-50 years. People exposed to the external environment are also more likely to suffer from stormy asthma and men are more likely to be affected than women [32]. Elderly people or those with common chronic respiratory diseases, such as asthma or chronic obstructive pulmonary disease (COPD), are more susceptible to negative health effects resulting from these phenomena. ...
Thunderstorm-triggered asthma (TA) can be defined as the occurrence of acute asthma attacks immediately following a thunderstorm during pollen seasons. Outbreaks have occurred across the world during pollen season with the capacity to rapidly inundate a health care service, resulting in potentially catastrophic outcomes for allergicpatients. TA occurs when specific meteorological and aerobiological factors combine to affect predisposed atopic patients with IgE-mediated sentitization to pollen allergens. Thunderstorm outflows can concentrate aeroallergens, most commonly grass pollen but also other pollens such as Parietaria and moulds in TA, at ground level to release respirable allergenic particles after rupture by osmotic shock related to humidity and rainfall. Inhalation of high concentrations of these aeroallergens by sensitized individuals can induce early asthmatic responses which can be followed by a late inflammatory phase. There is evidence that, during pollen season, thunderstorms can induce allergic asthma outbreaks, sometimes also severe asthma crisis and sometimes deaths in patients suffering from pollen allergy. It has been observed that changes in the weather such as rain or humidity may induce hydratation of pollen grains during pollen seasons and sometimes also their fragmentation which generates atmospheric biological aerosols carrying allergens. Asthma attacks are induced for the high concentration at ground level of pollen grains which may release allergenic particles of respirable size after rupture by osmotic shock. In other words, it is a global health problem observed in several cities and areas of the world that can strike without sufficient warning, inducing sometimes severe clinical consequences also with deaths of asthma patients. Due to constant climate change, future TA events are likely to become more common, more disastrous and more unpredictable, as a consequence it is important to have deep knowledge on this topic to prevent asthma attacks. Other environmental factors, such as rapid changes in temperature and agricultural practices, also contribute to causing TA.
... The interaction between air pollution and aeroallergens has been demonstrated in studies showing that pollutants are able to increase pollen production [18] and to modify pollen morphology and content [19], as well as the chemotactic and the immunomodulatory properties [20]. Open-field studies confirmed these findings. ...
... Interestingly, some studies demonstrated that pollen grains can absorb heavy metals but, also, nitrate and sulphur, while others showed that particles can agglomerate on the surface of pollen grains [22][23][24]. This pollen-particle interaction may modulate the allergen release and the absorption of pollen proteins to airborne particles, finally contributing to the increase in pollen allergies and asthma in highly polluted areas [19]. ...
Climate change (CC) is one of the main contributors to health emergencies worldwide. CC appears to be closely interrelated with air pollution, as some pollutants like carbon dioxide (CO2), nitrogen oxides (NOx) and black carbon are naturally occurring greenhouse gases. Air pollution may enhance the allergenicity of some plants and, also, has an adverse effect on respiratory health. Children are a uniquely vulnerable group that suffers disproportionately from CC burden. The increasing global warming related to CC has a big impact on plants’ lifecycles, with earlier and longer pollen seasons, as well as higher pollen production, putting children affected by asthma and allergic rhinitis at risk for exacerbations. Extreme weather events may play a role too, not only in the exacerbations of allergic respiratory diseases but, also, in favouring respiratory infections. Even though paediatricians are already seeing the impacts of CC on their patients, their knowledge about CC-related health outcomes with specific regards to children’s respiratory health is incomplete. This advocates for paediatricians’ increased awareness and a better understanding of the CC impact on children’s respiratory health. Having a special responsibility for children, paediatricians should actively be involved in policies aimed to protect the next generation from CC-related adverse health effects. Hence, there is an urgent need for them to take action and successfully educate families about CC issues. This paper aims at reviewing the evidence of CC-related environmental factors such as temperature, humidity, rainfall and extreme events on respiratory allergic diseases and respiratory infections in children and proposing specific actionable items for paediatricians to deal with CC-related health issues in their clinical practice.
... The increased effect of aeroallergens on sensitive individuals and the augmented severity of respiratory symptoms is clearly shown in the literature [48][49][50]. ...
In recent years, the environmental impacts of climate change have become increasingly evident. Extreme meteorological events are influenced by climate change, which also alter the magnitude and pattern of precipitations and winds. Climate change can have a particularly negative impact on respiratory health, which can lead to the emergence of asthma and allergic respiratory illnesses. Pollen is one of the main components of the atmospheric bioaerosol and is able to induce allergic symptoms in certain subjects. Climate change affects the onset, length, and severity of the pollen season, with effects on pollen allergy. Higher levels of carbon dioxide (CO2) can lead to enhanced photosynthesis and a higher pollen production in plants. Pollen grains can also interact with air pollutants and be affected by thunderstorms and other extreme events, exacerbating the insurgence of respiratory diseases such as allergic rhinitis and asthma. The consequences of climate change might also favor the spreading of pandemics, such as the COVID-19 one.
... Anemophilous plants liberate large quantities of pollens to ensure their reproduction, exceeding 500 billion grains per individual for some tree species [1,2]. This pollen dispersal in ambient air is a major cause of seasonal allergies worldwide and the role of pollen grains in triggering conjunctivitis, allergic rhinitis, or asthma is well established [3][4][5][6]. The number of people affected by pollen-induced allergies is significant, totalling approximately 400 million people in the world suffering from allergic rhinitis, and 300 million from asthma [7]. ...
The monitoring of airborne pollen has received much attention over the last decade, as the prevalence of pollen-induced allergies is constantly increasing. Today, the most common technique to identify airborne pollen species and to monitor their concentrations is based on manual analysis. Here, we present a new, low-cost, real-time optical pollen sensor, called Beenose, that automatically counts and identifies pollen grains by performing measurements at multiple scattering angles. We describe the data pre-processing steps and discuss the various statistical and machine learning methods that have been implemented to distinguish different pollen species. The analysis is based on a set of 12 pollen species, several of which were selected for their allergic potency. Our results show that Beenose can provide a consistent clustering of the pollen species based on their size properties, and that pollen particles can be separated from non-pollen ones. More importantly, 9 out of 12 pollen species were correctly identified with a prediction score exceeding 78%. Classification errors occur for species with similar optical behaviour, suggesting that other parameters should be considered to provide even more robust pollen identification.
... An accurate detection of the spring plant phenology is key to the global carbon balance [14], plant competition research [15], pest control and pollen forecasts [16]. Frequent earth observation data is important for accurate estimation of spring phenology. ...
Deciduous forests spring phenology plays a major role in balancing carbon cycle. The cloud cover affects images acquired from optical sensor and reduces its performance in monitoring phenology. Synthetic Aperture Radar (SAR) can regularly acquire images day and night independent of weather conditions, which offers more frequent observations of vegetation phenology compared to optical sensors. However, it remains unclear how SAR data-derived indices vary across different growth stages of forests. Here we explored the relationship between cross ratio (CR) index derived from Sentinel-1 data and deciduous forest growth process. We proposed a deciduous forests spring phenology extraction method using CR and compared the extracted start of growing season (SOS) with those extracted using Normalized Difference Vegetation Index (NDVI) derived from Sentinel-2 optical satellite data and Green Chromatic Coordinate (GCC) derived from ground PhenoCam data. We extracted the SOS of 41 PhenoCam sites over Continental United States in 2018 using dynamic threshold method. Our results showed that the variations of CR time series are closely related to the phenological processes of deciduous forests. The SOS extracted using CR data showed high consistency with those extracted using GCC (R
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= 0.46), with slightly lower accuracy compared with NDVI derived results (R
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= 0.62). Our study illustrates the value and mechanism of deciduous forests spring phenology extraction using SAR data, and provides reference for using SAR data to improve forest phenology extraction in addition to using optical remote sensing data, especially in rainy and cloudy regions.
... The allergen-independent mechanisms are not yet well understood. The release of lipid mediators from pollen during contact with mucous membranes may be one potential initiator of the inflammation, potentially leading to the adverse health outcomes (Traidl-Hoffmann et al., 2003). ...
In recent years, evidence of the synergistic effects of pollen and viruses on respiratory health has begun to accumulate. Pollen exposure is a known risk factor for the incidence and severity of respiratory viral infections. However, recent evidence suggests that pollen exposure may also inhibit or weaken viral infections. A comprehensive summary has not been made and a consensus on the synergistic health effects has not been reached. It is highly possible that climate change will increase the significance of pollen exposure as a cause of respiratory problems and, at the same time, affect the risk of infectious disease outbreaks. It is important to accurately assess how these two factors affect human health separately and concurrently. In this review article, for the first time, the data from previous studies are combined and reviewed and potential research gaps concerning the synergistic effects of pollen and viral exposure are identified.
... In a mechanism analogous to pollen-related asthma response, it is likely that cardiopulmonary-related health effects arise due to immune defence reactions occurring in atopic individuals with endpoints inside and outside the respiratory system, including the heart and the associated circulatory system [9]. The possible nexus between allergenic activity and cardiopulmonary disease concerns due to the high prevalence of cardio-respiratory disease and atopy [10,11]. ...
(1) Background: Limited research has suggested that cardiopulmonary health outcomes should be considered in relation to pollen exposure. This study sets out to test the relationship between pollen types (grasses, trees, weeds) and cardiovascular, lower respiratory and COPD health outcomes using 15 years (2003–2017) of data gathered in Adelaide, South Australia; (2) Methods: A time-series analysis by months was conducted using cardiopulmonary data from hospital admissions, emergency presentations and ambulance callouts in relation to daily pollen concentrations in children (0–17) for lower respiratory outcomes and for adults (18+). Incidence rate ratios (IRR) were calculated over lags from 0 to 7 days; (3) Results: IRR increases in cardiovascular outcomes in March, May, and October were related to grass pollen, while increases in July, November, and December were related to tree pollen. IRRs ranged from IRR 1.05 (95% confidence interval (CI) 1.00–1.10) to 1.25 (95% CI 1.12–1.40). COPD increases related to grass pollen occurred only in May. Pollen-related increases were observed for lower respiratory outcomes in adults and in children; (4) Conclusion: Notable increases in pollen-related associations with cardiopulmonary outcomes were not restricted to any one season. Prevention measures for pollen-related health effects should be widened to consider cardiopulmonary outcomes.
... At least 40% of the European population is affected by these allergies [1]. Not only do these allergies have a high impact on human health [2,3] but they also represent a significant financial burden on health care systems and on society as a whole [4]. Additionally, the prevalence of pollen-induced allergies is likely to increase and the symptoms are expected to become more severe due to climate change and atmospheric pollution [5,6]. ...
Pollen grains strongly affect human health by inducing allergies. Although the monitoring of airborne pollens particles is of major importance, the current measurement methods are manually conducted and are expensive, limiting the number of monitoring stations. Thus, there is a need for relatively low-cost instruments that can work automatically. The possible detection of pollen in urban ambient air (Paris, France) has been reported using the LOAC optical aerosol counter. These measurements indicate that the pollen grains and their nature could be determined using their scattering properties. For this purpose, the scattering functions (intensity and linear polarization) of 21 different airborne pollens were established in the laboratory using a PROGRA2 instrument. The linear polarization curves were close together, with a maximum polarization lower than 10% in the red domain and 5% in the green domain. The variability from one sample to another was partly due to the different sizes of the grains. An instrument with an absolute accuracy of about ±1% for polarization measurements should then be needed, coupled with a counting instrument to take into account the effects of size. On the other hand, the scattering curves for intensity presented with different shapes and strong differences up to a factor of 20 at some scattering angles, due to the size, shape, surface texture, and composition of the grains. Thus, we propose a proof of concept for new automated sensors that can be used in dense networks to count and identify pollen grains by analyzing the light they scatter at some specific angles.
... For example, floral timing influences activity of nectar-gathering insects (Gérard et al., 2020) and influences vulnerability to damaging weather events . Flowering also impacts allergen prevalence (Jochner et al., 2013;Traidl-Hoffmann et al., 2003), human psycho-emotional well-being (Cameron et al., 2012;Burroughs, 2017), tourism (Wang et al., 2017), aesthetics (Kareiva et al., 2007), and agriculture (Duraiappah et al., 2005;Menzel, 2002). Given that climate change and densification of cities is likely to continue to impact the drivers of tree phenology, such as air temperatures, it is vital to have tree monitoring tools to understand the trends and intensity of both foliar and floral shifts in trees. ...
Trees are bioindicators of global climate change and regional urbanization, but available monitoring tools are ineffective for fine-scale observation of many species. Using six accelerometers mounted on two urban ash trees (Fraxinus americana), we looked at high-frequency tree vibrations, or change in periodicity of tree sway as a proxy for mass changes, to infer seasonal patterns of flowering and foliage (phenophases). We compared accelerometer-estimated phenophases to those derived from digital repeat photography using Green Chromatic Coordinates (GCC) and visual observation of phenophases defined by the USA National Phenology Network (NPN). We also drew comparisons between two commercial accelerometers and assessed how placement height influenced the ability to extract seasonal transition dates. Most notably, tree sway data showed a greenness signal in an urban environment and produced a clear flowering time-series and peak flowering signal (PF), marking the first observations of a flower phenophase using accelerometer data. Estimated start of spring (SOS) from accelerometers and time-lapse GCC were more similar than start of autumn (SOA); accelerometers lagged behind the time-lapse camera dates by three and four days for SOS and 13 and 14 days for SOA for each tree. Estimates for SOS and SOA from accelerometers and time-lapse cameras aligned closely with different NPN phenophases. The two commercial accelerometers produced similar season onset: a difference of 2.4 to 3.8 days for SOS, 2.1 days for SOA, and 0.5 to 2.0 days for PF. Accelerometers placed at the main crown branch point versus higher in the canopy showed a difference of 0.2 to 4.9 days for SOS and -1.5 to 1.7 days for PF. Our results suggest accelerometers present a novel opportunity to objectively monitor reproductive tree biology and fill gaps in phenology observations. Furthermore, widely available accelerometers show promise for scaling up from individual trees to the landscape level to aid forest management and assessing climate change impacts to tree phenology.
... 10 Although exposure to pollen grain allergens is predominantly limited to the upper respiratory tract, the inflammatory response and subsequent biological effects could impact organ systems remote from the site of exposure, such as the cardiovascular system. 11 Inflammation is known to play a key role in both acute and chronic coronary syndromes. 12,13 The extent of inflammation in patients with acute coronary syndrome (ACS), as reflected by higher inflammatory markers such as C-reactive protein, is well-described and predicts worse cardiovascular outcomes. ...
Background
Atmospheric changes in pollen concentration may affect human health by triggering various allergic processes. We sought to assess if changes in pollen concentrations were associated with different acute coronary syndrome (ACS) subtype presentations and short‐term clinical outcomes.
Methods and Results
We analyzed data in consecutive patients presenting with ACS (unstable angina, non–ST‐segment–elevation myocardial infarction, and ST‐segment–elevation myocardial infarction) treated with percutaneous coronary intervention between January 2014 and December 2017 and enrolled in the VCOR (Victorian Cardiac Outcomes Registry). Baseline characteristics were compared among patients exposed to different grass and total pollen concentrations. The primary outcome was occurrence of ACS subtypes and 30‐day major adverse cardiac and cerebrovascular events (composite of mortality, myocardial infarction, stent thrombosis, target vessel revascularization, or stroke). Of 15 379 patients, 7122 (46.3%) presented with ST‐segment–elevation myocardial infarction, 6781 (44.1%) with non–ST‐segment–elevation myocardial infarction, and 1476 (9.6%) with unstable angina. The mean age was 62.5 years, with men comprising 76% of patients. No association was observed between daily or seasonal grass and total pollen concentrations with the frequency of ACS subtype presentation. However, grass and total pollen concentrations in the preceding days (2‐day average for grass pollen and 7‐day average for total pollen) correlated with in‐hospital mortality (odds ratio [OR], 2.17 [95% CI, 1.12–4.21]; P =0.021 and OR, 2.78 [95% CI, 1.00–7.74]; P =0.05), respectively, with a trend of 2‐day grass pollen for 30‐day major adverse cardiac and cerebrovascular events (OR, 1.50 [95% CI, 0.97–2.32]; P =0.066).
Conclusions
Increased pollen concentrations were not associated with differential ACS subtype presentation but were significantly related to in‐hospital mortality following percutaneous coronary intervention, underscoring a potential biologic link between pollen exposure and clinical outcomes.
... Ambient particulate matter (PM) is composed of all the solid and liquid particles suspended in the air including dust, pollen, soot, smoke, and liquid droplets [4]. It is said by allergists and immunologists that pollen is associated with the release of allergens and the development of allergic diseases and is considered to be one of the main sources of allergens in the air [5]. In addition, based on the report by WHO, allergic diseases are a global public health matter and have been categorized among the six most common chronic diseases worldwide [6][7][8][9]. ...
Since pollen is a major cause of allergies, collecting it from the environment seems to be beneficial. In this study, a new electro cyclone is proposed and simulated for collecting pollen from indoor environments. In this cyclone, an electrode is added to a traditional cyclone to apply additional force to particles that have already been pre-charged. The obtained results showed an increase of 14, 33 and 53 (%) in separation efficiency for pollen particle sizes of 10, 8 and 6 µm. Moreover, at lower inlet velocity, high electrostatic voltage enhances the efficiency, with the effect being more noticeable on finer particles. The validity of the simulation results was confirmed by comparing it with experimental and simulation findings of our previous study. It is also concluded that small electro cyclone systems are more efficient in removing fine particles from various gas streams.
... Pollen grains constitute a vital problem affecting human health since they cause allergic diseases such as asthma, rhinitis, and allergic conjunctivitis (Traidl-Hoffmann et al., 2003). The intensification of symptoms is strictly dependent on the degree of exposure to a given allergen and the ambient concentration of the allergen (Lipiec et al., 2005;Rapiejko et al., 2007). ...
The study's main objective was to specify the extent to which weather conditions were related to the course of birch pollen seasons in the years 1997–2020. The impact of atmospheric conditions on the daily concentrations of birch pollen grains, the Annual pollen integral (APIn), and the length of pollen seasons were studied. The dependency between each meteorological condition and various features of the birch pollen season was determined using Spearman’s rho correlation, the Kruskal–Wallis test, and cluster analysis with the k-means method. It has been shown that the duration of sunshine and average air temperature occurring within 14 days preceding the season has the most significant influence on the beginning of a birch pollen season. The value of daily birch pollen concentrations in Sosnowiec showed a statistically significant positive correlation with the duration of sunlight and the average and maximum wind speed. The daily concentration also depended on the synoptic situation: the mass airflow direction, the type of air mass inflow, and the type of weather front. The near-ground temperature influenced the APIn of birch pollen grains during the period of 14 days before the beginning of the season and the meteorological conditions occurring in the summer of the preceding year such as the maximum temperature, duration of sunlight, the maximum and average wind speed, and the relative air humidity. It was concluded that the length of birch pollen seasons decreased year by year.
... These small, light, dry pollen grains can be easily breathed in by humans. When inhaled, proteins and glycoproteins associated with these pollens can interact with the immune systems of sensitive individuals to produce an allergic response in the form of hay fever or allergic asthma (81). In Australia, the pollen count varies with seasons, geographic locations, and wind direction (82). ...
Objective: Various associations between different environmental exposures and asthma have been reported in different countries and populations. We aimed to investigate the associations between family, neighbourhood and psychosocial environmental factors and asthma-symptoms in Australia by conducting a systematic review and meta-analysis.
Data sources: We analyzed the primary research studies conducted in Australia across multiple databases, including PubMed, EMBASE and Scopus, published between 2000 and 2020.
Study selections: The reviews and analyses focused on the overall association of different environmental exposures with the exacerbation of asthma-symptoms or asthma-related hospital visits. Quality-effect meta-analysis was done to estimate the pooled odds ratio for different environmental exposures for asthma-symptoms.
Results: Among the 4,799 unique published articles found, 46 were included here for systematic review and 28 for meta-analysis. Our review found that psychosocial factors, including low socioeconomic condition, maternal depression, mental stress, ethnicity, and discrimination, are associated with asthma-symptoms. Pooled analysis was conducted on family and neighbourhood environmental factors and revealed that environmental tobacco smoking (ETS) (OR 1·69, 95% CI 1·19–2·38), synthetic bedding (OR 1·91, 95% CI 1·48–2·47) and gas heaters (OR 1·40, 95% CI 1·12–1·76) had significant overall associations with asthma-symptoms in Australia.
Conclusion: Although the studies were heterogeneous, both systematic review and meta-analysis found several psychosocial and family environmental exposures significantly associated with asthma-symptoms. Further study to identify their causal relationship and modification may reduce asthma-symptoms in the Australian population.
... These small, light, dry pollen grains can be easily breathed in by humans. When inhaled, proteins and glycoproteins associated with these pollens can interact with the immune systems of sensitive individuals to produce an allergic response in the form of hay fever or allergic asthma (81). In Australia, the pollen count varies with seasons, geographic locations, and wind direction (82). ...
... Plants in our living environment can contribute to the onset of asthma and allergies. Proteins in pollen can act as allergens (Traidl-Hoffmann et al., 2003). A number of ornamental plants (including ornamental trees) produce pollen grains with allergenic 69 properties and thus constitute a potential risk to human health. ...
The aim of the risk assessment for the ornamental horticulture production chain is to identify the hazards and risks for plant health, nature and the environment, public health and animal health that could arise in the various phases of the ornamental horticulture production chain and to recommend measures to reduce these risks.
... Beyond air pollution, weather can modulate pollen allergy symptoms. Thunderstorms with co-occurring extreme grass pollen concentrations have been associated with an escalation of asthma-and respiratory-related hospital admissions of individuals who were highly sensitized to grass pollen (e.g., Melbourne thunderstorm asthma epidemic) (83,84). The aforementioned pulmonary, cardiovascular, cognition, sleep, and HRQoL bodies of literature have uncommonly considered how air pollution and/or weather may have modified outcomes attributed to pollen. ...
... Pollen structure and composition are dependent on the dispersal pathway of the species (wind, water, insects, animals) in order to protect the male gametophyte best from external environmental conditions. These unique properties have already drawn researchers' attention [2]; notwithstanding, it is well known that most pollens contain allergens that constitute a potential risk to human health [1,9]. A few protocols have already been established for the elimination of such components and/or the chemical extraction of sporopollenin from fern spores and pollen grains [10][11][12] to encapsulate drugs [13,14], lipids [15], cells [16], proteins [17,18], or chemical catalysts [19,20]. ...
Pollen grains are natural microcapsules comprised of the biopolymer sporopollenin. The uniformity and special tridimensional architecture of these sporopollenin structures confer them attractive properties such as high resistance and improved bioadhesion. However, natural pollen can be a source of allergens, hindering its biomedical applicability. Several methods have been developed to remove internal components and allergenic compounds, usually involving long and laborious processes, which often cannot be extended to other pollen types. In this work, we propose an abridged protocol to produce stable and pristine hollow pollen microcapsules, together with a complete physicochemical and morphological characterization of the intermediate and final products. The optimized procedure has been validated for different pollen samples, also producing spo-ropollenin microcapsules from Matricaria species for the first time. Pollen microcapsules obtained through this protocol presented low protein content (4.4%), preserved ornamented morphology with a nanoporous surface, and low product density (0.14 g/cm 3). These features make them interesting candidates from a pharmaceutical perspective due to the versatility of this biomaterial as a drug delivery platform.
... Beyond air pollution, weather can modulate pollen allergy symptoms. Thunderstorms with co-occurring extreme grass pollen concentrations have been associated with an escalation of asthma-and respiratory-related hospital admissions of individuals who were highly sensitized to grass pollen (e.g., Melbourne thunderstorm asthma epidemic) (83,84). The aforementioned pulmonary, cardiovascular, cognition, sleep, and HRQoL bodies of literature have uncommonly considered how air pollution and/or weather may have modified outcomes attributed to pollen. ...
Background: While airborne pollen is widely recognized as a seasonal cause of sneezing and itchy eyes, its effects on pulmonary function, cardiovascular health, sleep quality, and cognitive performance are less well-established. It is likely that the public health impact of pollen may increase in the future due to a higher population prevalence of pollen sensitization as well as earlier, longer, and more intense pollen seasons, trends attributed to climate change. The effects of pollen on health outcomes have previously been studied through cross-sectional design or at two time points, namely preceding and within the period of pollen exposure. We are not aware of any observational study in adults that has analyzed the dose-response relationship between daily ambient pollen concentration and cardiovascular, pulmonary, cognitive, sleep, or quality of life outcomes. Many studies have relied on self-reported pollen allergy status rather than objectively confirming pollen sensitization. In addition, many studies lacked statistical power due to small sample sizes or were highly restrictive with their inclusion criteria, making the findings less transferable to the “real world.”
Methods: The EPOCHAL study is an observational panel study which aims to relate ambient pollen concentration to six specific health domains: (1) pulmonary function and inflammation; (2) cardiovascular outcomes (blood pressure and heart rate variability); (3) cognitive performance; (4) sleep; (5) health-related quality of life (HRQoL); and (6) allergic rhinitis symptom severity. Our goal is to enroll 400 individuals with diverse allergen sensitization profiles. The six health domains will be assessed while ambient exposure to pollen of different plants naturally varies. Health data will be collected through six home nurse visits (at approximately weekly intervals) as well as 10 days of independent tracking of blood pressure, sleep, cognitive performance, HRQoL, and symptom severity by participants. Through repeated health assessments, we aim to uncover and characterize dose-response relationships between exposure to different species of pollen and numerous acute health effects, considering (non-)linearity, thresholds, plateaus and slopes.
Conclusion: A gain of knowledge in pollen-health outcome relationships is critical to inform future public health policies and will ultimately lead toward better symptom forecasts and improved personalized prevention and treatment.
... PCGs from allergenic PGs are a source of allergenic proteins and NAD(P)H oxidases in the respirable fine fraction of atmospheric aerosols, which can cause allergic airway inflammation (Bacsi et al. , 2006Boldogh et al. 2005). Immunological studies have highlighted the potential immunological role of pollen lipid molecules in allergic immune response regulation Traidl-Hoffmann et al. 2003;Gilles et al. 2012;Bublin et al. 2014;Dahl 2018;Aglas et al. 2018). However, lipid molecules in allergenic airborne pollen fragments of respirable size are still understudied (Farah et al. 2020a). ...
The lipid fraction of birch pollen grains (BPGs) is not yet fully described, although pollen lipid molecules may play a role in the allergic immune response. The mechanisms by which atmospheric pollutants modify allergenic pollen grains (PGs) are also far from being elucidated despite high potential effects on allergic sensitization. This work is a contribution to a better description of the lipid profile (both external and cytoplasmic) of BPGs and of alterations induced by gaseous air pollutants. Several lipid extractions were performed using organic and aqueous solvents on BPGs following exposure to ozone and/or nitrogen dioxide and under conditions favoring the release of internal lipids. Ozone reacted with alkenes to produce aldehydes and saturated fatty acids, while nitrogen dioxide was shown to be unreactive with lipids. NO2 exhibited a protective effect against the reactivity of alkenes with ozone, probably by competition for adsorption sites. The decreased reactivity of ozone during simultaneous exposure to NO2/O3 raised the possibility of a Langmuir-Hinshelwood mechanism. Oxidation reactions induced by exposure of BPGs to ozone did not substantially modify the extraction of lipids by aqueous solvent, suggesting that the bioaccessibility of lipids was not modified by oxidation. On the contrary, the rupture of PGs appeared to be a key factor in enhancing the bioaccessibility of bioactive lipid mediators (linoleic and α-linolenic acids) in an aqueous solution. The internal lipid fraction of BPGs has specific characteristics compared with external lipids, with more abundant hexadecanoic acid, tricosanol, and particularly unsaturated fatty acids (linoleic and α-linolenic acids). Several mechanisms of action of gaseous pollutants on allergenic pollen were identified in this study: gaseous air pollutants can (i) modify the external lipid fraction by reactivity of alkenes, (ii) adsorb on the surface of PGs and be a source of oxidative stress after inhalation of PGs, and (iii) promote the release of cytoplasmic bioactive lipids by facilitating pollen rupture.
... These trees have airborne pollen that may cause several allergic reactions in the human body, such as asthma, allergic rhinoconjunctivitis and eczema (D'Amato et al., 2007). Pollen allergies are highly prevalent worldwide and pose daunting threats to human health (D'Amato and Liccardi, 2002;Traidl-Hoffmann et al., 2003;Liu et al., 2010). A previous study conducted for the entire Beijing metropolitan region indicated that only 37% of the tree species were allergenic, but allergenic trees were more common in residential areas than in other land use types (Mao et al., 2013). ...
Urban trees provide a range of ecological services for urban dwellers. This is particularly true in residential areas where these services are known and valued. The abundance and diversity of trees determine and indicate the provision of ecological services by trees, while various characteristics of residential areas determine and indicate the abundance and diversity of trees within those areas. Exploring the abundance and diversity of trees in residential areas and their major driving and indicative factors is important for evaluating, predicting, and thus improving the ecological services provided by trees. Here, we selected 87 residential areas in Beijing through spatially stratified random sampling. Unlike the quadrat survey that is usually used, we conducted a detailed investigation of the abundance and diversity of trees in residential areas through a tree-by-tree survey and explored the major driving and indicative factors of the abundance and diversity of the trees. In the 87 sampled residential areas, 69 tree taxa belonging to 34 families were identified, and we found that the 10 most common species accounted for 55.9% of all trees. Trees in the residential areas had both high allergenic risk and high ornamental value. In newly built residential areas, the allergenic risk decreased but the ornamental value remained high. Average building height and distance to the city center were the two major driving and indicative factors of residential tree abundance, both of which were positive indicators, and the former played a larger role than that of the latter. In this study, distance to the city center was the only predicator of tree species diversity, and was also a positive indicator. The size of residential area did not show any relationship with tree abundance or diversity. Even though housing age and housing price were not included in the forecasting model, both showed a negative correlation with tree abundance, i.e., an opposite legacy effect and luxury effect. The results of this study can help in understanding tree abundance and diversity and their driving and indicative factors in residential areas in highly urbanized cities and can provide potential guidance for future residential tree planning and management.
... Normally, pollen structure is supported by a solid outer wall known as the exine. Once airborne pollens are placed in a lipid-rich stigma or encounter rain, the pollen will absorb the medium and swell [56,57]. Furthermore, the proteins in the outer wall or inside the pollen are extremely water-soluble. ...
In recent decades, airborne allergens for allergic respiratory diseases have been found to increase significantly by a process of converting coniferous forests into broad-leaved forests in Korea. This study was conducted to evaluate factors, including airborne pollen counts, micromorphology, and flowering phenology, that can affect oak pollen-related allergic symptoms. The catkin of Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) showed the most rapidly blooming catkin on Julian day 104 in flower development. Among six species, the last flowering was observed on Julian day 119 in Korean oak (Quercus dentata Thunb.). The pollen dispersal was persisted for about 32 days from Julian day 104 to Julian day 136. Airborne pollen was observed about 2 weeks after flowering phase H, the senescence phase. Pollen size varied by species, with the largest from Q. mongolica (polar axis length, PL = 31.72 µm, equatorial axis length, EL = 39.05 µm) and the smallest from Jolcham oak (Quercus serrata Murray) (PL = 26.47 µm, EL = 32.32 µm). Regarding pollen wall structure, endexine of Q. dentata was coarsely laminated or fragmented. The endexine thicknesses of Sawtooth oak (Quercus acutissima Carruth.) and Q. serrata were thick and stable, whereas Galcham oak (Quercus aliena Blume), Q. mongolica, and Oriental cork oak (Quercus variabilis Blume) had thinner endexines. The area occupied by pollenkitt of Q. variabilis was significantly larger than that of Q. acutissima. Importantly, Q. variabilis had a distinctly thick 17 kDa protein band, a presumed major allergen. Oak species differ in pollen protein composition, and thus there is a possibility that the allergenic activity of pollen proteins vary depending on oak species. This study highlights the fact that native oak species in Korea differ in flowering pattern of male flowers, pollen morphology, and pollen chemical constituents. These discrepancies in flowering and pollen properties imply variable allergic responses to oak pollen from different species.
... Woody species are now leafing out an average of 18 days earlier than they did in the 1850s, and are advancing at a rate of 5 days °C -1 warming (Polgar et al., 2013). Insect-pollinated plants tend to have greater advancement of flowering than wind-pollinated plants, annuals have greater advancement than perennials, and early spring bloomers have greater advancement than mid-and late-Spring bloomers (Fitter & Fitter 2002;Hepper 2003;Traidl-Hoffmann et al., 2003). Plant development theory says higher temperatures prompt earlier growth in heat-sensitive species (Menzel 2000). ...
Urban land cover contributes to higher temperatures in urban areas compared to adjacent rural
areas, which can cause an earlier start of the growing season for urban vegetation. Variations in plant
community characteristics between urban and rural areas also produce intra-urban differences in
vegetation phenophases, although few studies have investigated differences in phenology between plant
functional types in multiple urban environments. In this study I used an exploratory analysis based on the
Landsat Phenology Algorithm and weather station data to quantify differences in leaf-onset dates for
different plant functional types in the New York City Metropolitan Area. The results demonstrate that
Landsat can be used to identify urban-rural variations in leaf-onset for different plant functional types,
and that these variations are driven by different climate variables depending on plant functional type.
Furthermore, results from such analyses suggest that long-term changes in leaf onset vary across different
plant functional types—i.e., grasslands may be advancing at a slower rate than forests.
Keywords: urban heat island; vegetation phenology; Landsat
... Therefore, this study was conducted in different months of the year to consider the effects of temperature, precipitation, humidity and environmental contaminants. The materials on the wings and bodies of the whiteflies can act as the pollen and cause allergic reactions in individuals (30). Rain and low humidity (below 60%) and low or high temperatures disrupt development of the insects. ...
Background: The reports of numerous outbreaks of whiteflies from different parts of the world have increased its medical importance. The aim of this study was to determine relationship between environmental changes and climatic factors with the outbreak of the whitefly population in Tehran, the capital of Iran.
Methods: This study was carried out in urban areas of Tehran, where the increasing population of whiteflies was reported frequently during 2018. In order to entrap the whiteflies, 20 yellow sticky cards smeared with white refined grease were installed on the trunks of the trees at twice per month as trapping time intervals. The captured flies were transferred and conserved in cans containing 70% alcohol and were counted accurately under a stereomicroscope. To determine the relationship between air quality index, precipitation, air temperature and air humidity as environmental and climatic factors with the abundance of whiteflies, change point analysis and Generalized Estimating Equations (GEE) was used.
Results: The most density of white flies per trap was 256.6 and 155.6 in early October and late September respectively. The number moved closer to zero from November to April. The population of whiteflies was inversely correlated with the level of air quality index (p= 0.99) and precipitation (p= 0.95), and it had a direct correlation with the high temperature. Also, the population of whiteflies had a direct correlation with the level of air humidity in the first half of the year
Conclusion: According to these findings, during spring and summer from early May to early October.
... Indeed, the potential health impact of these stressors (such as those resulting from oxidative stress) is now a growing concern (Consales et al., 2012). Similarly, the relationship between CD and pollen has not yet been assessed, even though the latter is well known to (i) trigger immune responses through a large number of mechanisms, and (ii) to form aerial colloids with bacteria and metals (Traidl-Hoffmann et al., 2003). To date, sunlight is the only physical ecological stressor to have been documented in a study that explored the spatial relationship between the risk of CD and the UV light intensity in France (Nerich et al., 2011). ...
Although the incidence of Crohn's disease has increased worldwide over the past 30 years, the disorder's exact causes and physiological mechanisms have yet to be determined. Given that genetic determinants alone do not explain the development of Crohn's disease, there is growing interest in “environmental” determinants. In medical science, the term “environment” refers to both the ecological and social surroundings; however, most published studies have focused on the latter. In environmental and exposure sciences, the term “environment” mostly relates to contamination of the biotope. There are many unanswered questions on how environmental hazards might contribute to the pathogenesis of Crohn's disease. Which pollutants should be considered? Which mechanisms are involved? And how should environmental contamination and exposure be evaluated?
The objective was to perform a systematic review of the literature on Crohn's disease and environmental contamination. We searched the PubMed, Google Scholar, Scopus, ISI Web of Science and Prospero databases. We considered all field studies previous to April 2019 conducted on human health indicators, and evaluating exposure to all type of physical, biological and chemical contamination of the environment. The lack of clear answers to date can be ascribed to the small total number of field studies (n = 16 of 39 publications, most of which were conducted by pioneering medical scientists), methodological differences, and the small number of contaminants evaluated. This make it impossible to conduct a coherent and efficient meta-analysis. Based on individual analysis of available studies, we formulated five recommendations on improving future research: (i) follow up the currently identified leads - especially metals and endocrine disruptors; (ii) explore soil contamination; (iii) gain a better knowledge of exposure mechanisms by developing transdisciplinary studies; (iv) identify the most plausible contaminants by developing approaches based on the source-to-target distance; and (v) develop registries and cohort-based analyses.
... In the case of alder, these numbers shrink to 11.1% and 4.6%, respectively (Samoliński et al. 2014). Pollen grains constitute an important issue affecting human health because they induce allergenic diseases like asthma, rhinitis, and allergic conjunctivitis (Traidl-Hoffmann et al. 2003). The severity of symptoms increases as concentration of aeroallergens rises (Rapiejko et al. 2007). ...
The influence of atmospheric circulation conditions on pollen concentrations of two taxons (Betula and Alnus) in Wroclaw, Poland, for the years 2005–2014 was analysed. Pollen concentration was analysed separately for twenty circulation types that were determined using objective classification. The results indicate the atmospheric circulation conditions favourable for both low and high pollen concentrations over Central Europe. Pollen concentrations vary significantly according to circulation types. The highest pollen concentrations for both taxons are typical for warm, sunny, and dry anticyclonic circulation types with anticyclone in the lower and upper troposphere, especially for types with advection from the SW. The lowest pollen concentrations are observed for cold, wet, and cloudy cyclonic types with advection from the northern sectors. There is also a positive and statistically significant trend in the frequency of circulation types favourable for high concentrations of Betula and Alnus.
... Pollen has deleterious effects on human health. Allergic rhinitis is estimated to affect up to 30% of adults and 40% of children [1], and hay fever and allergic asthma as much as 25% of the population [2]. Effective allergen avoidance has shown improvement in the allergy symptoms [1]. ...
Several studies have used regression analyses to forecast pollen concentrations, yet few have applied a deep neural network in their research. This study implements a deep convolutional neural network with the great potential to recognize patterns of pollen phenomena that enable the prediction of pollen concentrations. We train the model using data from 2009 to 2015 from multiple meteorological data sets, satellite data, and processed data reflecting pollen flux as input for the model. The model forecasts pollen counts one to seven days ahead for the entire year of 2016. Comparison of daily forecasts to observations, the algorithm obtains a relatively high index of agreement and Pearson correlation coefficient of up to 0.90 and 0.88 respectively. An evaluation of categorical statistics based on defined threshold levels shows satisfactory results. Critical Success Index of the model forecasts is as high as 0.887 for weed pollen, 0.646 for tree pollen, and 0.294 for grass pollen. Forecasts of grass pollen exhibit the largest decrease in accuracy because of the strong variance in annual pollen concentrations. Forecasts of weed pollen exhibit the greatest consistency, with a 7-day forecast correlation and index of agreement of 0.82 and 0.77 respectively during the peak season. This correlates with the consistency of annual and seasonal trends of weed pollen within the study area. Compared to the conventional modeling approaches, convolutional neural network shows a promising ability to predict pollen for multiple days to allow individuals with allergies to take proper precautions during high pollen days.
... Several researchers (Schappi et al. 1997;Chathurika et al. 2017;Wozniak et al. 2018) found that in light rain conditions, tree pollen grain releases antigens or sub-pollen inner particles contained within the grain into the atmosphere. Lacroix (2005) pointed out that laboratory work made by his team revealed that if pollen is exposed to pollution (O 3 , NO 2 , SO 2 ), an increase of the frequency of rupture, pollen surface cracks, or deformation of the exine is observed which facilitate the release of allergens (Traidl-Hoffmann et al. 2003). Moreover, the percentage of pollen which ruptures whenever immersed in water (or exposed to high humidity found within clouds and fog) is significantly higher if the grain has been preexposed to pollutant. ...
The aim of this study is to analyze the synergy between environmental factors (pollutant, allergenic birch pollen, weather) and its relationship with asthma hospitalization in Montreal, Canada. The data is stratified into weather types and the study restricted to spring season to limit the impact of multiple confounders. Results shows that the daily count of asthma hospitalization (spring 2006–2008) in situation of warm fronts or trowals (daily average of 3.78 counts, CI 95% 2.95–4.61) was much higher (p < 0.001) than in other situations (2.49 counts, CI 95% 2.37–2.71). Moreover, the explained variance of asthma hospitalization due to air pollution rises from about less than 7% (in the case of no stratification) to about 28% (R = 0.53, p < 0.05 with stratification). Statistical tests for interaction and overall results point towards a synergy between environmental factors which exacerbates asthma. A new concept named frontal asthma is proposed to explain several results found here and in the open literature.
... Les effets potentiels des lipides sur l'inflammation des voies respiratoires et la modulation des réactions allergiques a fait l'objet d'une littérature abondante [43,44,51,52]. La fraction lipidique des pollens allergisants est toutefois encore largement inconnue, de même que les effets de la pollution sur celle-ci. ...
Résumé
La pollution atmosphérique intervient sur l’allergie aux pollens par au moins trois voies : par ses effets directs sur la santé humaine, par la modification de la santé des végétaux, par l’altération directe du grain de pollen allergisant. Cette revue de la littérature traite de ce dernier point : les effets chimiques ou biologiques de la pollution atmosphérique sur le grain de pollen (GP). Les effets sur la santé de ces modifications du GP ne sont pas détaillés dans cette revue de la littérature qui s’intéresse spécifiquement aux modifications biologiques, chimiques ou structurales du GP par la pollution atmosphérique. Les effets du CO2 sur les plantes et leur reproduction sont abordés dans l’article de J.-P. Besancenot sur le changement climatique.
... Health data from allergists confirmed that the number of people sensitized to Ambrosia pollen is continuously increasing, from about 30% in France and Austria, up to 80% of pollen allergic patients in Hungary (Burbach et al., 2009). Actual data from the literature reveal the complex effects of pollen on human health, being considered more than an allergen carrier and from this perspective ragweed pollen is one of the most intensively studied allergenic pollen (Traidl-Hoffmann et al., 2003). The actual Ambrosia pollen map in Europe is depicted in Figure 1. ...
Honeybee products have recently begun to attract attention with their effects on athlete performance. In the present study, it was aimed to investigate the effects of honeybee products’ mixtures on the performance and some blood biochemical parameters of young trained gymnasts. Twenty-four young gymnasts aged between 6 and 12 years were observed for 4 weeks as they continued their usual daily training schedules. The gymnasts were divided into three groups. Group 1 was administered a mixture of honey and bee pollen at a dose of 50 g/day, whereas Group 2 was provided with a mixture of honey, bee pollen, royal jelly and propolis. Group 3 served as the control group and was administered a placebo of wheat starch at a dose of 50g/day. In the beginning and at the end of the study, performance parameters and biochemical parameters of young gymnasts were determined. After treatment, grip force and muscular strength measurements increased in Group 2 (p<0.05). The muscular endurance tests in the two honeybee product mixtures treatment groups showed improvement after supplementation (p<0.05). The improvement noted in the power test in Group 1 was significantly higher than the other groups (p<0.05). There was no significant difference between treatment and placebo groups in all investigated biochemical parameters except total protein, which was lower in placebo group. Although bee products supplements were administered only for a short period of time, the gymnasts showed higher performance in some investigated parameters. It is recommended to conduct further long-term studies using bee products.
Climate change is a global threat to public health and causes/worsens various diseases including atopic dermatitis (AD), allergic, infectious, cardiovascular diseases, physical injuries and mental disorders. The incidence of allergy, such as AD, has increased over the last several decades, and environmental factors such as climate change have been implicated as a potential mechanism. A significant amount of literature has been published on the impact of climate factors, including cold and hot temperature, on the skin barrier and AD. Studies in several countries have shown a greater incidence of AD in children born in the colder seasons of fall and winter. The effect of cold and warm temperature on itch, skin flares, increased outpatient visits, skin barrier dysfunction, development of AD, and asthma exacerbations have been reported. Understanding mechanisms by which changes in temperature influence allergies is critical to the development of measures for prevention and treatment of allergic disorders, such as AD and asthma. Low and high temperature induce production of proinflammatory cytokines and lipid mediators such as IL-1beta, thymic stromal lymphopoietin (TSLP), and prostaglandin E2, and cause itch and flares by activation of transient receptor potential vanilloid channels (TRPVs) such as TRPV1, TRPV3, and TRPV4. TRPV antagonists may attenuate temperature-mediated itch, skin barrier dysfunction, and exacerbation of AD.
Climate change will alter environmental risks that influence pulmonary health, including heat, air pollution, and pollen. These exposures disproportionately burden populations already at risk of ill health, including those at vulnerable life stages, with low socioeconomic status, and systematically targeted by oppressive policies. Climate change can exacerbate existing environmental injustices by affecting future exposure, as well as through differentials in the ability to adapt; this is compounded by disparities in rates of underlying disease and access to health care. Climate change is therefore a dire threat not only to individual and population health but also to health equity.
Purpose of review:
This review examines the impact of climate change on the respiratory health of children, with a focus on temperature, humidity, air pollution, and extreme weather events. Climate change is considered the greatest health threat of our time, and childreen are especially at risk. This review is timely and relevant as it provides an overview of the current literature on the effects of climate change on children's respiratory health, and the implications of these findings for clinical practice and research.
Recent findings:
The findings of this review suggest that climate change has a significant impact on children's respiratory health, with temperature, humidity, air pollution, and extreme weather events being key contributory factors. Increases in extreme weather events such as heatwaves, wildfires, floods, droughts, hurricanes and dust storms all cause the health of children's respiratory system to be at increased risk.
Summary:
The findings of this review suggest that climate change has a significant impact on children's respiratory health, and that mitigation and adaptation strategies are necessary to protect children from the harmful effects of climate change and improve their respiratory health. Overall, a comprehensive and integrated approach is necessary to protect children from the increasing impacts of climate change.
Outdoor air pollution is associated with exacerbations of allergic diseases, including asthma, allergic rhinitis, and other atopic conditions. The increased allergic disease prevalence has been linked to this urbanization, industrialization, and economic growth globally. Air pollutants are well-known to disrupt the epithelium leading to specific diseases in any organ system that has epithelial linings. This review provides an overview of the health effects of air pollution on allergic disorders and specifically addresses how it may impact the epithelial barrier in the upper and lower respiratory tracts to facilitate the health effects associated with these exposures.
Background:
While the relationship between pollen and respiratory allergies is well-documented, the role of short-term pollen exposure in food allergy and eczema flares has not previously been explored. We aimed to investigate these associations in a population-based sample of children.
Methods:
We investigated 1- (n = 1108) and 6-year-old (n = 675) children in the grass pollen season from the HealthNuts cohort. Grass pollen concentrations were considered on the day of testing (lag 0), up to three days before (lag 1-lag 3) and cumulatively (lag 0-3). Associations between grass pollen and food skin-prick test reactivity (SPT ≥ 2 mm at age 1 year and ≥ 3 mm at age 6 years), eczema flares, challenge-confirmed food allergy, reaction threshold to oral food challenges (OFC), and serum food-specific IgE levels were analyzed using either logistic or quantile regression models. Atopy and family history of allergic disease were considered as potent effect modifiers.
Results:
Grass pollen at lag 0-3 (every 20 grains/m3 increase) was associated with an up to 1.2-fold increased odds of food SPT reactivity and eczema flares in 6-year-olds. In 1-year-olds, the associations were only observed for peanut in those with a family history of food allergy. Increasing grass pollen concentrations were associated with a lower reaction threshold to OFC and higher serum IgE levels in peanut-allergic 1-year-olds only.
Conclusion:
Increasing grass pollen concentration was associated with increased risk of food SPT reactivity and eczema flares in children. The associations in peanut-allergic infants may be related to immune activation and/or peanut and grass pollen cross-reactivity leading to a lower reaction threshold.
Allergy is a complex condition that results from different causative factors and different kinds of reactions, which caused by vibrant interactions ranged from genetic predisposition, environmental factors, food reaction, animals, insects, to a dysfunctional immune system. A public concern has grown in response to the increasing prevalence of allergy and related atopic conditions. Although the underlying mechanism of the true causes of allergy is complicated due to insufficient data and variable methodologies, Immunoglobulin E (Ig E) is commonly accepted as a specific index for allergic diseases among many indices used to test allergy. The aim of the study was to perform analysis of food allergens, inhalatory allergens, and other allergens types in patients diagnosed with an allergy by testing specific IgE to understand the risk factors, prediction, preventing, and determine the treatment. The results showed that specific IgE serum levels are significantly higher in patients sensitized to D. pteronyssinus and D. farinae allergens. However, more data and studies are needed to investigate the local allergens that cause allergy.
Pollen particles enter indoor areas through various routes, negatively affecting indoor air quality and human health. Therefore, it is important to measure the indoor and outdoor concentrations of pollen and to study the factors influencing the indoor/outdoor pollen concentration (I/O) ratio. Here, we review recent developments in pollen research, focusing on experimental studies on the I/O ratio and contributing factors, and suggest avenues for further research. Based on a literature search of 108 publications, the development, basic principles, advantages, and disadvantages of pollen samplers are summarized, and factors influencing the I/O ratio are summarized. The results showed that pollen type, ventilation, indoor ornamental plants, and human activities significantly affected the value of the I/O ratio, which ranged from 0 to 0.5. Values of I/O ratio of 0.5–1 and higher were mainly found in studies with pollen diameters ranging from 15–30 μm. A window that opened perpendicular to the dominant outdoor wind direction and a larger window opening area also increased the I/O ratio. Outdoor pollen can adhere to human surfaces and enter a room through human activity, increasing the I/O ratio. The results of this study will help other researchers to understand the state of research on pollen I/O ratios and hopefully provide suggestions for future research directions.
Pollen, the male gametophyte of flowering plant species, is one of the most predominant sources of environmental allergens, and a significant cause of allergic disease. This review discusses the nature of pollen proteins as allergens, their effect on the human immune system. The influence of cross-reactive pollen allergens to the incidence of food sensitivities is also discussed. Flowering plant species that posses allergenic pollen, identified with allergens cloned from these species, are also discussed.
Exposure to allergenic tree pollen is an increasing environmental health issue in urban areas. However, reliable, well-documented, peer-reviewed data on the allergenicity of pollen from common tree species in urban environments are lacking. Using the concept of ‘riskscape’, we present and discuss evidence on how different tree pollen allergenicity datasets shape the risk for pollen-allergy sufferers in five cities with different urban forests and population densities: Barcelona, Montreal, New York City, Paris, and Vancouver. We also evaluate how tree diversity can modify the allergenic risk of urban forests. We show that estimates of pollen exposure risk range from 1 to 74% for trees considered to be highly allergenic in the same city. This variation results from differences in the pollen allergenicity datasets, which become more pronounced when a city’s canopy is dominated by only a few species and genera. In an increasingly urbanized world, diverse urban forests offer a potentially safer strategy aimed at diluting sources of allergenic pollen until better allergenicity data is developed. Our findings highlight an urgent need for a science-based approach to guide public health and urban forest planning.
Pollen grains emitted by urban vegetation are the main primary biological airborne particles (PBAPs) which alter the biological quality of urban air and have a significant impact on human health. This work analyses the interactions which exist between pollen-type PBAPs, meteorological variables, and air pollutants in the urban atmosphere so that the complex relationships and trends in future scenarios of changing environmental conditions can be assessed. For this study, the 1992-2018 pollen data series from the city of Granada (southeast Spain) was used, in which the dynamics of the total pollen as well as the 8 main pollen types (Cupressaceae, Olea, Pinus, Platanus, Poaceae, Populus, Quercus and Urticaceae) were analysed. The trend analysis showed that all except Urticaceae trended upward throughout the series. Spearman's correlations with meteorological variables showed that, in general, the most influential variables on the pollen concentrations were the daily maximum temperature , relative humidity, water vapor pressure, global radiation, and insolation, with different effects on different pollen types. Parallel analysis by neural networks (ANN) confirmed these variables as the predominant ones, especially global radiation. The correlation with atmospheric pollutants revealed that ozone was the pollutant with the highest influence, although some pollen types also showed correlation with NO 2 , SO 2 , CO and PM 10. The Generalized Linear Models (GLM) between pollen and pollutants also indicated O 3 as the most prominent variable. These results highlight the active role that pollen-type PBAPs have on urban air quality by establishing their interactions with meteorological variables and pollutants, thereby providing information on the behaviour of pollen emissions under changing environmental conditions.
Allergic diseases have remarkably increased in recent years. Nowadays, efforts for curing and management of these disorders are an important concern worldwide. Allergen‐specific immunotherapy (ASIT) has recently gained more attention as a means for the management of allergic diseases. Adjuvants or helper agents are materials applied for better stimulating and shifting of protective responses, and these belong to an extremely diverse collection of complexes. The main function of adjuvants includes acting as depot foundations, transferring vehicles, and immunostimulators. Immunostimulatory adjuvants have gained increasing attention for ASIT. In this regard, the present study provides a review of old and new adjuvants used in allergen immunotherapy. The use of adjuvants to stimulate the immune system has always been considered. Today, nanoparticles are being used as new adjuvants to better stimulate the immune system in allergen‐specific immunotherapy, with promising results.
Background
Both air pollution and airborne pollen can cause respiratory health problems. Since both are often jointly present in ambient air, it is important to control for one while estimating the effect of the other when considering pollution-abating policies. To date only a limited number of studies have considered the health effects of both irritants jointly for a general population, and for a sufficiently long time period to allow for variation in seasonal concentrations of both components. The primary goal of this study is to determine the causal impact of fine particulate matter (PM2.5) on hospital visits and related treatment costs, while controlling for potentially confounding pollen effects. Our study area is the metropolitan hub of Reno/Sparks in Northern Nevada.
Methods
Taking advantage of a rare sample of daily pollen counts over a prolonged period of time (2009–2015), we model the effects of PM2.5 and pollen on respiratory-related hospital admissions for the population at large, plus specific age groups. Pollen data are provided by a local allergy clinic. Data on PM2.5 and other air pollutants are obtained from the U.S. Environmental Protection Agency's air quality data web site. We collect daily meteorological data from the National Centers for Environmental Information's data repository. Data on hospital admissions are given by the Nevada Center for Surveys, Evaluations, and Statistics. Our econometric approach centers on a fully robust count data (Poisson) model, estimated via Quasi-Maximum Likelihood.
Results
We find that for our sample PM2.5 effects are largely robust to the inclusion of both pollen counts and temporal indicators. In contrast, pollen effects vanish when time fixed effects are added, pointing at their correlation with unobserved temporal confounders. At the same time, model fit improves with the inclusion of temporal indicators. Based on our preferred specification, we find a significant PM2.5 effect of approximately 0.5% additional hospital visits per day due to a one μg/m3 increase in PM2.5. This translates into expected augmented treatment costs of $2700 per day for the same unit-change in PM2.5. These figures can mount quickly when more pronounced and/or longer episodes of particulate matter pollution are considered, perhaps due to wildfire smoke. For instance, the expected increase in patients and costs due to a month-long 10-unit-jump of PM2.5 over the long-run annual average would amount to an extra 70 patients and approximately $680,000 in additional treatment costs.
Pollen pollution and allergy are becoming prominent issues in China. However, few studies on pollinosis have been reported. As an allergen in the atmosphere, allergenic Humulus scandens pollen was collected from four districts of Shanghai, including Wusong (WS), Jiading (JD), Xujiahui (XJH) and Songjiang (SJ). The mass concentrations of SO2, NO2, O3, PM10, and PM2.5 (particulate matter with air dynamic diameter less than 10 and 2.5 µm, respectively) near the four sampling sites were also recorded during Humulus scandens pollen season. The allergenicity of the Humulus scandens pollen was assessed by using of a rat model and enzyme linked immunosorbent assay (ELISA). Relationships between the allergenicity and air pollutants were correlated. Our results demonstrated that the biological viability of the pollens collected from the four districts exhibited no significant differences. ELISA and dot blotting results further demonstrated that the serum of sensitized rats exhibited much higher immune-reactive response than that of control groups. Western blotting showed that the 15 KD (1KD = 1000 dalton) proteins of Humulus pollen led to the allergic response. The allergenic intensity of Humulus pollen protein from different samples followed the pattern: WS > JD > XJ > SJ. There was a negative relationship between the allergenicity of Humulus pollens and PM10 (R = -0.99) / PM2.5 (R = -0.73), and a positive relationship with O3 (R = 0.92). These data clearly showed that PM10 and PM2.5 could enhance Humulus pollen protein release, and O3 could aggravate the allergenicity of the Humulus pollen.
The prevalence of asthma and allergic diseases has increased dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor vehicles has been indicated as one of the major risk factors responsible for this increase. Although genetic factors are important in the development of asthma and allergic diseases, the rising trend can be explained only in changes occurred in the environment. Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world. Due to climate change, air pollution patterns are changing in several urbanized areas of the world, with a significant effect on respiratory health. The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Associations between thunderstorms and asthma morbidity in pollinosis subjects have been also identified in multiple locations around the world. Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollens especially in presence of specific weather conditions. The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases. Factor clouding the issue is that laboratory evaluations do not reflect what happens during natural exposition, when atmospheric pollution mixtures in polluted cities are inhaled. In addition, it is important to recall that an individual’s response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not depend only on the increased production of air pollution, but rather on atmospheric factors that favour the accumulation of air pollutants at ground level. Considering these aspects governments worldwide and international organizations such as the World Health Organization and the European Union are facing a growing problem of the respiratory effects induced by gaseous and particulate pollutants arising from motor vehicle emissions.
Within the last decade the study of phenology has taken on a new legitimacy in the area of climate change research. A growing literature reveals that a change in the timing of natural events is occurring in a wide range of locations and affecting a wide range of species. Changes in spring have been those most commonly reported, with the emphasis on an advance in spring linked to an increase in temperature. Detection of change in autumn is hampered by a smaller pool of available data, events that are harder to define (such as leaf coloration), and various influencing environmental factors triggering autumnal phases. Despite this, the general pattern may be towards a delay in autumn. Plant, animal and abiotic responses, especially in spring, are quite similar. Thus, it would appear that winter is being squeezed at both ends, and this effect, of increasing the growing season, should become more pronounced in the face of predicted global warming. Copyright © 2002 Royal Meteorological Society.
Although environmental factors such as precipitation and temperature are
recognized as influencing pollen production, the impact of rising atmospheric
carbon dioxide concentration ([CO2]) on the
potential growth and pollen production of hay-fever-inducing plants is
unknown. Here we present measurements of growth and pollen production of
common ragweed (Ambrosia artemisiifolia L.) from
pre-industrial [CO2] (280 mol
mol–1) to current concentrations (370 mol
mol–1) to a projected 21st century concentration
(600 mol mol–1). We found that exposure to current
and elevated [CO2] increased ragweed pollen
production by 131 and 320%, respectively, compared to plants grown at
pre-industrial [CO2]. The observed
stimulations of pollen production from the pre-industrial
[CO2] were due to an increase in the number
(at 370 mol mol–1) and number and size (at 600 mol
mol–1) of floral spikes. Overall, floral weight as
a percentage of total plant weight decreased (from 21% to 13%),
while investment in pollen increased (from 3.6 to 6%) between 280 and
600 mol mol–1 CO2. Our
results suggest that the continuing increase in atmospheric
[CO2] could directly influence public health
by stimulating the growth and pollen production of allergy-inducing species
such as ragweed.
An aerobiological and phenological investigation on the olive tree was carried out during three years in two areas: Cordoba (Spain) and Perugia (Italy). In these countries, this species is economically important and those areas were chosen because of the long series of aeropalynological data (1982–1998) available, obtained by means of identical volumetric pollen traps. The aim of this study was to use phenological observations to prove the real contribution to the pollen curves in different cultivated areas. Results show that in Cordoba province (302.152 ha) the pollen curve is characterised by different peaks because of the pollination of different cultivated crops. In some cases, these crops are located far from the pollen trap (50 km) but pollen is transported thanks to favourable winds during the flowering period. In Perugia (750 ha) the pollen curve is characterised by only one peak; it is very concentrated because of the proximity of the investigated crops. The objective of this research was to obtain information on this species in order to elaborate statistical models aimed at forecasting the potential fruit production based on the amount of pollen released into the atmosphere.
Quercus pollen and meteorological data for several years from eight sites in Spain have been statistically analysed to select the threshold temperature and calculate the mean heat accumulation for predicting the Quercus pollination start in different climatic areas. The growing degree days method, which assumes the daily temperature varies as a sine wave, was used for heat accumulation calculations. Threshold temperatures between 4 and 12 °C were chosen using linear regression equations forced through the origin and their root mean square error (RMSE) of predicted against the observed dates for each observation site. Above the threshold, the average growing degree days (up to 1999) for the studied years was taken as the predictor value. Results showed a relationship between the selected threshold and elevation and a stronger and statistically significant correlation between threshold and yearly mean temperature, for each site. Regression analysis indicated that the selected threshold and the calculated heat accumulation were optimum for most of the localities. The validity of the results was tested using the meteorological data for the year 2000 as independent variable and this confirmed that there were only a few days difference between the predicted and observed day of the first pollen release for most of the studied localities.
Long term observations of atmospheric pollen offer the possibility of studying patterns in fluctuations in the airborne pollen presence. In this study, birch pollen measured at five monitoring stations in Europe with records of 18 to 30 years, have been analysed comparatively on three aspects: trends and fluctuations of annual sums of daily concentrations, and starting dates of airborne presence. The results show weakly rising trends at all five stations. The observed fluctuations in airborne birch pollen quantities are suggestive of synchronous, alternatingly cyclic rhythms, beit with a-synchronous aberrant years and phase shifts. For the starting dates of the birch pollen season the air temperature during the preceding 4 decades-of-days are of decisive importance.
In order to predict the beginning of the pollen season, a model comprising the Utah phenoclimatography Chill Unit (CU) and ASYMCUR-Growing Degree Hour (GDH) submodels were used to predict the first bloom in Alnus, Ulmus and Betula. The model relates environmental temperatures to rest completion and bud development. As phenologic parameter 14 years of pollen counts were used. The observed dates for the beginning of the pollen seasons were defined from the pollen counts and compared with the model prediction. The CU and GDH submodels were used as:
Aspirin-sensitive rhinitis is characterized by severe perennial nasal congestion and discharge. The study questioned whether this disease, like immunoglobulin E-mediated rhinitis, might be associated with local recruitment and activation of T-lymphocytes, mast cells and eosinophils with parallel increases in “T-helper2-type” cytokines.Nasal biopsies from 10 patients with aspirin-sensitive rhinitis and 12 healthy controls subjects were studied. Nasal mucosal sections were examined by immunohistochemistry in order to determine cell phenotypes and by in situ hybridization to detect cells expressing messenger ribonucleic acid (mRNA) for cytokines.In aspirin-sensitive rhinitis there were increases in total (CD3+) (p=0.05) and activated (CD25+) T-cells (p=0.007), total (major basic protein (MBP) positive) (p=0.004) and activated (monoclonal antibody which recognizes the cleaved form of eosinophil cationic protein (EG2) positive) eosinophils (p=0.003), tryptase+ mast cells (p=0.04) and CD68+ macrophages (p=0.002). Neutrophils and cells expressing human leukocyte antigen-DR were no different. Marked increases were observed in the numbers of interleukin (IL)-5 mRNA+ cells (p=0.004) in aspirin-sensitive patients, whereas lower numbers of IL-4 mRNA+ cells were observed, with a trend for a difference from controls (p=0.07). No differences were observed for either IL-2 or interferon-γ.In conclusion, in aspirin-sensitive rhinitis there is intense inflammation of the nasal mucosa characterised by T-lymphocytes, eosinophils and mast cells. The predominance of macrophages and disproportionate increase in interleukin-5 compared to interleukin-4 messenger ribonucleic acid expression suggests that factors other than “allergic” mechanisms may be important in this disease.
Daily variations in Cupressaceae pollen counts were analysed, together with climatic variables in the southwest of Spain,
in order to understand the bioclimatic variables affecting Cupressaceae flowering in a Mediterranean climate. The study was
carried out using the Spanish Aerobiology Network recommendations, using a Burkard Hirst-type spore trap. Regression analyses
were applied to the pollen counts of the winter months of 13 consecutive years. The regression analysis applied to each year
indicated that temperature is the most important variable to include in the model. Temperature affected the pollen counts
differently according to the yearly climatic trend. During the coldest years, pollen counts depended on the minimum temperature,
while in the warmest ones they were affected by higher temperatures. However, during the driest years, pollen counts depended
more on the humidity level, while in the wettest years they depended more on the hours of sunshine.
Changes in phenology (seasonal plant and animal activity driven by environmental factors) from year to year may be a sensitive and easily observable indicator of changes in the biosphere. We have analysed data from more than 30 years of observation in Europe, and found that spring events, such as leaf unfolding, have advanced by 6 days, whereas autumn events, such as leaf colouring, have been delayed by 4.8 days. This means that the average annual growing season has lengthened by 10.8 days since the early 1960s. These shifts can be attributed to changes in air temperature.
Although the occurrence of intracellular glasses in seeds and pollen has been established, physical properties such as rotational correlation times and viscosity have not been studied extensively. Using electron paramagnetic resonance spectroscopy, we examined changes in the molecular mobility of the hydrophilic nitroxide spin probe 3-carboxy-proxyl during melting of intracellular glasses in axes of pea (Pisum sativum L.) seeds and cattail (Typha latifolia L.) pollen. The rotational correlation time of the spin probe in intracellular glasses of both organisms was approximately 10−3 s. Using the distance between the outer extrema of the electron paramagnetic resonance spectrum (2Azz) as a measure of molecular mobility, we found a sharp increase in mobility at a definite temperature during heating. This temperature increased with decreasing water content of the samples. Differential scanning calorimetry data on these samples indicated that this sharp increase corresponded to melting of the glassy matrix. Molecular mobility was found to be inversely correlated with storage stability. With decreasing water content, the molecular mobility reached a minimum, and increased again at very low water content. Minimum mobility and maximum storage stability occurred at a similar water content. This correlation suggests that storage stability might be at least partially controlled by molecular mobility. At low temperatures, when storage longevity cannot be determined on a realistic time scale, 2Azz measurements can provide an estimate of the optimum storage conditions.
Background Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 μim in diameter) to smaller size fractions < 2.5 μ (fine particles, PM2.5). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution.Objective We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air.Methods We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron -microscopic imaging techniqueResults DECP are visualized as small carbon spheres, each 30–60 nm in diameter, forming fractal aggregates about 1–2μ in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p I. binds to one defined class of fine particles, DECP.Conclusion DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p I under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.
Various indications for shifts in plant and animal phenology due to climate change have been observed. First, this article presents a review of plant phenological changes observed in the last few years for Europe and North America. In the second part, the analysis of phenological seasons in Germany of more than 4 decades (1951–1996) is reported as an example for bio-monitoring by plant phenology. This study has the major advantages of a dense geographical coverage due to data of the phenological network of the German Weather Service and a good seasonal coverage due to 16 phenophases. The results of different methods of trend analysis, and then the spatial and annual variability of these trends are discussed.
Air pollution is supposed to enhance the risk of allergy. Investigations of the influence of environmental pollutants on allergic inflammatory reactions are therefore of increasing importance. Pollen grains which are the major source or outdoor aeroallergens are said to probably express an altered allergenicity when emitted into a polluted air. We investigated the behavior of pollen grains which had been collected from four differently polluted regions in North Rhine-Westphalia, FRG. Samples were taken with Burkhard traps and/or high volume samplers. In addition, native grass pollen have been exposed to extracts of airborne particulate matter in vitro in a dose- and time-dependent manner. The samples were further processed for scanning and transmission electron microscopy as well as for determination of protein content and release using IEF and SDS-PAGE immunoblot techniques.
The results obtained show that (1) there is an overall higher concentration of pollen grains in polluted urban areas than in rural regions, independent of weather conditions; (2) emission peaks of SO2, NO2/NOx or atmospheric fine dust, but not of O3, usually precede peaks of high pollen concentrations; (3) pollen grains collected from highly polluted regions are significantly more contaminated with agglomerations of airborne particulates, and the intensity of pollen/particle binding depends on amount and composition of organic compounds adsorbed to the particle; and (4) incubation of purified grass pollen with extracts of atmospheric fine dust results in dose- and time-dependent alterations of structural pollen integrity and of protein release, probably leading to altered allergenicity.
The results indicate that there is a complex interaction between pollen grains and air pollutants, not only with respect to daily emission peaks but also through direct binding of particulate matter to the pollen surface. Therefore, dust-laden pollen grains from heavily polluted areas can induce cytotoxic and mutagenic reactions in addition to sensitization. This fact has to be taken into account when assessing influences of air pollution on allergic inflammatory response.
The pollen grain is the carrier of the male gametes or their progenitor cell, in higher plants. In a single unit, each grain contains all the genetic information required to specify an entire haploid plant organism (for example, pollen embryoids in tissue culture), or to unite with the female gamete at fertilization and form a diploid zygote and, hence, a new sporophyte. The male gametes, the sperm cells (or their progenitor, the generative cell) are housed entirely within the cytoplasm of the vegetative cell. This is dehydrated like a seed at maturity, and is filled with storage reserves. The vegetative cell is surrounded by a complex, intricately patterned outer wall, and its nucleus controls at least the initial growth and metabolism of the pollen tube following germination.
Although environmental factors such as precipitation and temperature are recognized as influencing pollen production, the impact of rising atmospheric carbon dioxide concentration ([ CO2]) on the potential growth and pollen production of hay- fever- inducing plants is unknown. Here we present measurements of growth and pollen production of common ragweed (Ambrosia artemisiifolia L.) from pre- industrial [CO2] (280 mu mol mol(-1)) to current concentrations (370 mu mol mol(-1)) to a projected 21st century concentration (600 mu mol mol(-1)). We found that exposure to current and elevated [CO2] increased ragweed pollen production by 131 and 320%, respectively, compared to plants grown at pre- industrial [CO2]. The observed stimulations of pollen production from the pre- industrial [CO2] were due to an increase in the number (at 370 mu mol mol(-1)) and number and size (at 600 mu mol mol(-1)) of floral spikes. Overall, floral weight as a percentage of total plant weight decreased (from 21% to 13%), while investment in pollen increased (from 3.6 to 6%) between 280 and 600 mu mol mol(-1) CO2. Our results suggest that the continuing increase in atmospheric [CO2] could directly influence public health by stimulating the growth and pollen production of allergy- inducing species such as ragweed.
Very long chain lipids contribute to the hydrophobic cuticle on the surface of all land plants and are an essential component of the extracellular pollen coat in the Brassicaceae. Mutations in Arabidopsis CER genes eliminate very long chain lipids from the cuticle surface and, in some cases, from the pollen coat. In Arabidopsis, the loss of pollen coat lipids can disrupt interactions with the stigma, inhibiting pollen hydration and causing sterility. We have positionally cloned CER6 and demonstrate that a wild-type copy complements the cer6-2 defect. In addition, we have identified a fertile, intragenic suppressor, cer6-2R, that partially restores pollen coat lipids but does not rescue the stem wax defect, suggesting an intriguing difference in the requirements for CER6 activity on stems and the pollen coat. Importantly, analysis of this suppressor demonstrates that low amounts of very long chain lipids are sufficient for pollen hydration and germination. The predicted CER6 amino acid sequence resembles that of fatty acid–condensing enzymes, consistent with its role in the production of epicuticular and pollen coat lipids >28 carbons long. DNA sequence analysis revealed the nature of the cer6-1, cer6-2, and cer6-2R mutations, and segregation analysis showed that CER6 is identical to CUT1, a cDNA previously mapped to a different chromosome arm. Instead, we have determined that a new gene, CER60, with a high degree of nucleotide and amino acid similarity to CER6, resides at the original CUT1 locus.
Background: Specific allergen from various pollen types has been found to be carried through the outdoor air, not only by intact pollen grains, but also by much smaller, paucimicronic particles. There is no complete agreement on whether, for birch (Betula), the seasonal appearance of atmospheric pollen allergen follows the fluctuation pattern of the pollen season.
Methods: Assessment of birch-pollen allergen in size-fractionated ambient aerosol was performed by descending elution of allergen from impaction strips of a five-stage cascade impactor, and compared with atmospheric birch-pollen concentrations as measured with a volumetric pollen trap.
Results: An overall similarity in the courses of the seasonal presence was found for both birch pollen and allergen in particles of all paucimicronic size fractions, although some airborne allergen was detected before and after the birch-pollen season.
Conclusions: Transfer of pollen allergen to both natural and pollutant environmental dust particles is thought to be the probable explanation of secondary allergen carriage by paucimicronic particles. Until simple techniques for direct and rapid assessment of atmospheric pollen allergen become available, the pollen count gives sufficiently reliable information about the seasonal course of airborne pollen allergen.
We conducted an atmospheric pollen survey using a Durham sampler from 1983 through 1998 in Toyama City, Japan. We investigated yearly changes in the pollen season of Japanese cedar Cryptomeria japonica and analyzed the relationships between climatic factors and changes in the pollen counts. The results were as follows: (1) The first day of the Japanese cedar pollen season advanced from mid-March to late February. The yearly change in the first day was significantly associated with the mean temperature in February. (2) An increase in total pollen count was significantly associated with the mean temperature in the previous July. (3) The duration of the pollen season was suggested to be associated with the total pollen count. These results indicate that climate change, especially increasing global warming, influences the early pollen scatter and increase in pollen count as well as elongation of pollen season of Japanese cedar. Further study will be needed to clarify its effect on the health of pollen-allergy patients.
Records of the start of Birch pollen seasons monitored at three sites in the UK for periods of up to forty two years indicate a recent trend for the pollen seasons to begin earlier. This trend shows a close relationship to an increase in cumulative temperatures in the months of January, February and March recorded near each of the sites during the study period.
The antioxidative abilities of pollen extracts were evaluated using lipid peroxidation model system. Ethanol-soluble fraction (ESF) was most active followed by hot-water fraction (HWF). These abilities of pollen extracts were higher than that of 5 mM ascorbic acid and were similar to that of 1 mM α-tocopherol. Superoxide-scavenging capacities were decreased in the order water-soluble fraction > HWF > ESF. ESF showed the highest hydroxyl radical scavenging ability among these samples. The pollen extracts showed DPPH radical scavenging ability. Particularly the ability of ESF gradually increased with passage of the time (about 80% to 10 min). It suggests that the extracts of the pollen are good scavengers of active oxygen species. This property of the pollen seems to be important in prevention of various diseases such as cancer, cardiovascular diseases, and diabetes.
The start of the grass pollen season is compared over a network of standard sites for the six year period, 1987–1992. Five sites have records for the whole of this period, and a further four joined the network at different times since 1987. Two definitions of the start of the season were compared; those defined by the sum75 method tend to be later than those defined by the 98% method. Differences in the start dates were analysed in relation to cumulative temperatures above 5.5°C and monthly total rainfall from February to the end of June. Where comparisons can be made, seasons often start simultaneously in the south and the west. The variation in start dates shows a close relationship to cumulative temperatures and to rainfall in May and June but the patterns are complicated. Future work will analyse the data from the full geographical range of the network now that more sites are operating.
The in situ interaction between pollen and airborne particulate matter (APM) as well as the effect of extracts of APM on grass pollen (Dactylis glomerata) was studied. The samples were processed for structural analysis using scanning and transmission electron microscopy as well as for determination of protein content and release using immunoblot techniques. The results indicate a direct in situ interaction between pollen surfaces and APM. This effect is prominent in industrialized regions with high emission of organic pollutants. It is also found to occur near roads with heavy traffic. There is morphological evidence for preactivation of pollen by organic extracts of APM. Aqueous extracts, however, directly induce the release of allergens with altered antigenicity. It is concluded that the generation and release of allergenic aerosols in a humidified air is initiated and mediated by substances adsorbed to APM.
In the last decade it has become clear that the timing of many phenological processes, like the start of flowering and leaf unfolding in spring, have changed. The increase in temperature is believed to be the main cause. The earlier start of flowering will have consequences for the start of the pollen season, and thus for the start of the hay fever season. Millions of people world-wide will therefore experience the impact of climate change in their daily lives during spring and summer. In this paper we analyse the relation between climate parameters, especially temperature, and the start of the pollen season in the western part of the Netherlands based on daily pollen counts of the Leiden University Medical Centre and temperature measurements from 1969 till 2000 by the Royal Netherlands Meteorological Institute in De Bilt. The results indicate that there is a strong correlation between temperature and start of the pollen season. An advance of the start of the pollen season of 3 to 22 days has been observed. The potential future changes in the start of the pollen season under climate change scenarios are also discussed. Copyright © 2002 Royal Meteorological Society.
Various indications for shifts in plant and animal phenology resulting from climate change have been observed in Europe. This analysis of phenological seasons in Germany of more than four decades (1951–96) has several major advantages: (i) a wide and dense geographical coverage of data from the phenological network of the German Weather Service, (ii) the 16 phenophases analysed cover the whole annual cycle and, moreover, give a direct estimate of the length of the growing season for four deciduous tree species. After intensive data quality checks, two different methods – linear trend analyses and comparison of averages of subintervals – were applied in order to determine shifts in phenological seasons in the last 46 years. Results from both methods were similar and reveal a strong seasonal variation. There are clear advances in the key indicators of earliest and early spring (−0.18 to −0.23 d y−1) and notable advances in the succeeding spring phenophases such as leaf unfolding of deciduous trees (−0.16 to −0.08 d y−1). However, phenological changes are less strong during autumn (delayed by + 0.03 to + 0.10 d y−1 on average). In general, the growing season has been lengthened by up to −0.2 d y−1 (mean linear trends) and the mean 1974–96 growing season was up to 5 days longer than in the 1951–73 period. The spatial variability of trends was analysed by statistical means and shown in maps, but these did not reveal any substantial regional differences. Although there is a high spatial variability, trends of phenological phases at single locations are mirrored by subsequent phases, but they are not necessarily identical. Results for changes in the biosphere with such a high resolution with respect to time and space can rarely be obtained by other methods such as analyses of satellite data.
1.
Pollen grains accumulate many secondary plant products, especially flavonoids and carotenoids. Quantitative analysis have revealed that up to 2–4% of pollen dry weight consist of accumulated flavonols. For pollen ofCorylus avellana, a flavonol content of 0.286 ng per pollen grain could be measured.
2.
Short-time extraction experiments and pollen prints demonstrated that flavonoids are loosely associated with the pollen, and in contrast to vacuole-accumulated flavonoids, can be very easily removed from the grains. Experimental evidence is given for the assumption that these secondary components are located on the pollen wall and/or in its cavities.
Chromatographic (thin-layer, gas column, column chromatography) analyses of neutral lipids and fatty acids of reproductive tissues of Forsythia intermedia Zab., a self-incompatible species, were performed with two objectives in mind: 1. To determine whether there is a qualitative evolution of the different classes of lipids and fatty acids that could be correlated with the three functional stages observed during previous histochemical and ultrastructural studies. The stigmatic exudate and intracellular accumulations consist mainly of neutral lipids. 2. To compare the lipid composition of the stigma (both thrum and pin forms) with that of the style, the ovary, and the anther, and to investigate the possible existence of a stigma-specific lipid compound. Stigmatic neutral lipids are found mostly in a glyceridic mixture probably containing hydrocarbons and terpenes. The fatty acids identified are between C:7 and C: 12, with the maximum unsaturated form being a C: 18. During the secretory process there is no great qualitative diference between the neutral lipids and fatty acids found in the stigmas of thrum and pin forms. Sterols are present in styles, ovaries, and anthers, but not in stigmas. They represent the only difference in the lipid composition of these various floral structures.
Pollen, the male gametophyte of flowering plants, is a high energy material, which is collected by insects and stored as food reserve. Pollen has been used traditionally by humans for religious purposes and as supplementary food. Pollen is a concentrated, energy and vitamin rich food that in contemporary times is trot only consumed as a dietary component, but also is used in alternative medical treatments. Pollen has potential importance as a supplementary and survival food, and for conditioning of athletes. Pollen has been used medically in prostatitis, bleeding stomach ulcers and some infectious diseases, although such use has been questioned by the medical profession. Pollen may also be used for treatment and prevention of the high-altitude-sickness syndrome. Because some individuals are allergic to pollen, and various pollen species contain specific allergens, individual sensitivities must be tested before pollen is used as a treatment or as a supplementary food.
The aim of this work was to investigate thephenological behaviour of Betula in Galicia, NW Spain, and to examine therelationship between the Betula pollencurves and the flowering phenophase. Threetrees were chosen from the each of ninepopulations of Betula located atdifferent altitudes and phytogeographicpositions. Phenological observations of theflowering periods of Betula were made ineach of them. Environmental factors such asfrequency of mist, latitudinal and topographicposition, proximity of the ocean, degree ofsolar exposure, and altitude result inphenological differences between theinvestigated populations. The correlationbetween the Pollinic Production Index of Betula pollen in Galicia and theaerobiological data of the seven monitoringstations showed that the period in which thehighest concentrations were registered wasalmost synchronous with the flowering times atmost of the phenological stations studied.Other factors such as transport and reflotationshould also be taken into account to provide anadequate interpretation of the aerobiologicaldata of Betula pollen in the atmosphere.
Pollen allergens interact with the human immune system and the resulting IgE antibodies provide specific probes for their
identification and characterisation. In one case, grass allergenic proteins are expressed late in pollen development coincident
with the laying down of reserves. Sequence similarity of allergens has indicated possible functions for some allergens. The
major birch pollen allergen shows sequence similarity with pathogenesis-related proteins, which form a secondary response
in plant host-pathogen interactions and show anti-microbial activity. Some allergens of unknown function are cysteine-rich
proteins, while some others have cysteine-rich regions; for example, the major allergen from rye-grass pollen, Lol p 1, has
a cysteine-rich N-terminal region, while at the C-terminal region four tryptophan residues together with tyrosine and phenylalanine
residues resemble those of cellulose- or sugar-binding domains of other proteins. Several pollen allergens show sequence similarity
to cell wall-associated enzymes, while others show hydrolytic enzyme activity often associated with cell walls.