Environmental influences on childhood asthma: Climate change.

Climate change is a key environmental factor for allergic respiratory diseases, especially in childhood. This review describes the influences of climate change on childhood asthma considering the factors acting directly, indirectly and with their amplifying interactions. Recent findings on the direct effects of temperature and weather changes, as well as the influences of climate change on air pollution, allergens, biocontaminants and their interplays, are discussed herein. The review also focusses on the impact of climate change on biodiversity loss and on migration status as a model to study environmental effects on childhood asthma onset and progression. Adaptation and mitigation strategies are urgently needed to prevent further respiratory diseases and human health damage in general, especially in younger and future generations.

Impact of Fungal Spores on Asthma Prevalence and Hospitalization.

Despite making up a significant proportion of airborne allergens, the relationship between fungal spores and asthma is not fully explored. Only 80 taxa of fungi have so far been observed to exacerbate respiratory presentations, with Cladosporium spp., Aspergillus spp., Penicillium spp., and Alternaria spp. found to comprise the predominant allergenic airborne spores. Fungal spores have been found in indoor environments, such as hospitals and housing due to poor ventilation. Meanwhile, outdoor fungal spores exhibit greater diversity, and higher abundance and have been associated with hospitalizations from acute asthma presentations. In addition, fungal spores may be the underlying, and perhaps the "missing link", factor influencing the heightened rate of asthma presentations during epidemic thunderstorm asthma events. To improve our knowledge gap on fungal spores, airborne allergen monitoring must be improved to include not only dominant allergenic fungi but also provide real-time data to accurately and quickly warn the general public. Such data will help prevent future asthma exacerbations and thus save lives. In this review, we examine the health risks of prominent allergenic fungal taxa, the factors influencing spore dispersal and distribution, and why improvements should be made to current sampling methods for public health and wellbeing.

The phenomenon of thunderstorm asthma in Bavaria, Southern Germany: a statistical approach.

Higher incidences of asthma during thunderstorms can pose a serious health risk. In this study, we estimate the thunderstorm asthma risk using statistical methods, with special focus on Bavaria, Southern Germany. In this approach, a dataset of asthma-related emergency cases for the study region is combined with meteorological variables and aeroallergen data to identify statistical relationships between the occurrence of asthma (predictand) and different environmental parameters (set of predictors). On the one hand, the results provide evidence for a weak but significant relationship between atmospheric stability indices and asthma emergencies in the region, but also show that currently thunderstorm asthma is not a major concern in Bavaria due to overall low incidences. As thunderstorm asthma can have severe consequences for allergic patients, the presented approach can be important for the development of emergency strategies in regions affected by thunderstorm asthma and under present and future climate change conditions.

Allergenicity at component level of sub-pollen particles from different sources obtained by osmolar shock: A molecular approach to thunderstorm-related asthma outbreaks.

BACKGROUND: The so-called "thunderstorm asthma" (TA) is an uncommon but dramatic outbreak of asthma attacks occurring during a thunderstorm in the pollen and moulds season. Mechanisms which make the pollen able to enter the deeper airways and provoke severe asthma symptoms are still unclear. OBJECTIVE: To test the hypothesis that sub-pollen particles (SPPs) originated from the rupture by an osmotic shock of pollen associated with TA contain allergens. METHODS: After hydration, SPPs released from pollen grains of grass, pellitory, olive, cypress, ragweed and birch were isolated and determined by microscopy. Allergens were determined by in vitro ELISA inhibition tests indirectly using the sera from 10 polyreactive patients. An inhibition <50% was considered as negative, 50%-75% moderate and > 75% complete. RESULTS: The inhibition experiments showed that the SPPs from birch and cypress were unable to inhibit serum IgE reactivity to Bet v 1 and Cup a 1, respectively. Ragweed SPPs inhibited ragweed pollen extract and Amb a 1 by 75.8 ± 0.11% and 81.2 ± 0.15%, respectively. Olive and pellitory SPPs retained almost the whole IgE-binding capability in all cases tested. Grass SPPs inhibited 32 ± 0.06% of Lolium perenne Lol p 1 and 65% of Phleum pratense extracts, but results were highly variable for individual allergens (97.5%-0.03% for Phl p 2, 45.3 ± 0.12% for Phl p 5, 24.7 ± 0.22% for Phl p 6, and 38.3 ± 0.2% for Phl p 1). CONCLUSIONS: Inhibition experiments confirm the hypothesis that SSPs obtained after the osmotic shock of pollen involved in TA, namely grass, pellitory and olive tree pollen, contain allergens and therefore they can induce severe asthma attacks during thunderstorms.

Thunderstorm asthma epidemic - management challenges experienced by general practice clinics.

OBJECTIVES: To understand the challenges faced by general practice (GP) services in terms of personnel, materials, secondary support services, and discharge and communication obstacles during the thunderstorm asthma (TA) epidemic in 2016. METHODS: Qualitative study using semi-structured interviews and focus groups between September and October 2017. Participants were general practitioners (GPs), practice nurses, and administrative staff working on the TA epidemic days in the northern region of Melbourne, Australia. RESULTS: 18 participants contributed to the study from six clinic sites. Both daytime and evening clinics experienced a surge in respiratory patient presentations. After-hours clinics were inundated with asthma patients during the night of the thunderstorm. Consistent themes emerged about the challenges encountered by participants the most significant being limitation of medication, equipment, space, and personnel. The extraordinary influx of patients necessitated participants innovate solutions including recycling equipment, procuring medications from hospitals and community pharmacies, triage, altering management strategies and extending clinic hours. Participants were limited by the paucity of information from local services during the TA epidemic. CONCLUSION: This study supports the view that GP services made a substantial contribution to the emergency response on the evening of the TA epidemic that occurred in Melbourne in 2016. Demands on resources were considerable during and after the epidemic yet GP staff showed great resilience increasing clinic surge capacity. Our findings indicate significant barriers at an organizational level including resource limitations, inadequate operational information, and the absence of timely communication channels that impaired the response of GP services during a TA event.

Prevention of Allergic Asthma with Allergen Avoidance Measures and the Role of Exposome.

PURPOSE OF REVIEW: It is well known that combination of sensitization and exposure to inhaled environmental allergens is related to both the development and elicitation of symptoms of asthma and that avoidance of allergens would exert beneficial effects in the prevention and control of the disease. Other important factors include the relevance of other allergens, exposure to sensitizing agents also outside patient's home, exposure to irritants (like chemical air pollutants), and the involvement of the patient with a correct education. It is also likely that clinical phase of allergic airway disease and the degree of airways remodeling represent relevant factors for the clinical outcome of allergen avoidance procedure. We reviewed existing evidence on prevention of asthma through allergen avoidance. RECENT FINDINGS: The management of respiratory allergy is a complex strategy (including prevention, drugs, immunological, and educational interventions). In addition, it is difficult in real life to distinguish the efficacy of single interventions. However, a combined strategy is likely to produce clinical results. A combined strategy is likely to produce satisfactory management of asthma. Allergens are an important trigger factor for the development of symptoms of respiratory allergy, and avoidance measures are able to reduce allergen levels. It is likely that clinical phase of allergic airway disease and the degree of airways remodeling represents relevant factors for the clinical outcome of allergen avoidance procedures. Considering the management of respiratory allergy is a complex strategy; it is difficult in real life to distinguish the efficacy of single interventions. However, further studies better quantifying the effects of allergens are needed.

How can air quality affect health?

Over recent years, Australians have been subject to an unprecedented number of environmental events materially and visibly affecting air quality, including thunderstorm asthma and bushfire smoke. There is increasing evidence that poor air quality adversely affects health with consequences for mortality and morbidity with measured particulates (PM2.5) in January 2019 frequently exceeding World Health Organization standards. Biological factors can also impact air quality with thunderstorm asthma epidemics evidence of a prime example, the 2016 event being associated with severe impacts on health services. Given these events, consideration needs to be given to environmental health literacy which will support individuals with pre-existing illness to recognise and mitigate as far as possible the effects of adverse air quality. Recognising the impact of poor air quality should also urge physicians to advocate for clean air as a necessity for good health.

How Do Storms Affect Asthma?

PURPOSE OF REVIEW: There are observations in various geographical areas that thunderstorms occurring during pollen seasons can induce severe asthma attacks in pollinosis patients. RECENT FINDINGS: An accredited hypothesis explaining the association between thunderstorms and asthma suggests that storms can concentrate pollen grains at ground level, which may then release allergenic particles of respirable size in the atmosphere after their imbibition of water and rupture by osmotic shock. During the first 20-30 min of a thunderstorm, patients affected by pollen allergy may inhale a high quantity of the allergenic material that is dispersed into the atmosphere as a bioaerosol of allergenic particles, which can induce asthmatic reactions, often severe. Subjects without asthma symptoms, but affected by seasonal rhinitis can also experience an asthma attack. A key message is that all subjects affected by pollen allergy should be alerted to the danger of being outdoors during a thunderstorm in the pollen season, as such events may be an important cause of severe asthma exacerbations. In light of these observations, it is useful to predict thunderstorms and thus minimize thunderstorm-related events. Patients with respiratory allergy induced by pollens and molds need to be informed about a correct therapeutic approach of bronchial asthma by inhalation, including the use of bronchodilators and inhaled corticosteroids. The purpose of this review is to focalize epidemiological, etiopathogenetic, and clinical aspects of thunderstorm-related asthma.

News on Climate Change, Air Pollution, and Allergic Triggers of Asthma.

The rising frequency of obstructive respiratory diseases during recent years, in particular allergic asthma, can be partially explained by changes in the environment, with the increasing presence in the atmosphere of chemical triggers (particulate matter and gaseous components such as nitrogen dioxide and ozone) and biologic triggers (aeroallergens). In allergic individuals, aeroallergens stimulate airway sensitization and thus induce symptoms of bronchial asthma. Over the last 50 years, the earth's temperature has risen markedly, likely because of growing concentrations of anthropogenic greenhouse gas. Major atmospheric and climatic changes, including global warming induced by human activity, have a considerable impact on the biosphere and on the human environment. Urbanization and high levels of vehicle emissions induce symptoms of bronchial obstruction (in particular bronchial asthma), more so in people living in urban areas compared than in those who live in rural areas. Measures need to be taken to mitigate the future impact of climate change and global warming. However, while global emissions continue to rise, we must learn to adapt to climate variability.

A proposed explanation for thunderstorm asthma and leukemia risk near high-voltage power lines: a supported hypothesis.

Thunderstorm asthma and increased childhood leukemia risk near high-voltage power lines (HVPL) are occurrences whose mechanism of effect is not fully understood. This paper proposes and discusses a key similarity: both thunderstorms and HVPL generate a high enough electrical field in the environment to ionize nearby air and air-borne particles. I argue that the repeatedly demonstrated acute asthma response to pollen-laden air during thunderstorms is largely due to ionization of air-borne allergens, which adhere more readily and in greater quantity in the lungs than non-ionized particles. If these bind to mucous or phagocytic cells, it would enhance immune response. A rapid temperature drop and high ozone also seem to be drivers of thunderstorm asthma. This causal nexus provides strong support for the parallel situation of prolonged exposure to ionized particles near HVPL and an increased rate of childhood leukemia. Here, it is proposed that upwind carcinogens are ionized when passing HVPL and then residential and business areas. Published evidence for most steps are presented, but have not previously been published as a coherent whole, nor has it been suggested that the inhaled ionized micro-particle explanation for acute asthma may also explain development of childhood leukemia over time. The demonstrated series of events leading to increased deposition and retention of ionized particles in airways provides support for explaining both adverse health outcomes: acute thunderstorm asthma and increased risk of childhood leukemia near HVPL. Further support for this explanation of both outcomes is provided by effects of on-going proximity to highways.

Pollen and sub-pollen particles: External interactions shaping the allergic potential of pollen.

Pollen allergies, such as allergic rhinitis, are triggered by exposure to airborne pollen. They are a considerable global health burden, with their numbers expected to rise in the coming decades due to the advent of climate change and air pollution. The relationships that exist between pollens, meteorological, and environmental conditions are complex due to a lack of clarity on the nature and conditions associated with these interactions; therefore, it is challenging to describe their direct impacts on allergenic potential clearly. This article attempts to review evidence pertaining to the possible influence of meteorological factors and air pollutants on the allergic potential of pollen by studying the interactions that pollen undergoes, from its inception to atmospheric traversal to human exposure. This study classifies the evidence based on the nature of these interactions as physical, chemical, source, and biological, thereby simplifying the complexities in describing these interactions. Physical conditions facilitating pollen rupturing for tree, grass, and weed pollen, along with their mechanisms, are studied. The effects of pollen exposure to air pollutants and their impact on pollen allergenic potential are presented along with the possible outcomes following these interactions, such as pollen fragmentation (SPP generation), deposition of particulate matter on pollen exine, and modification of protein levels in-situ of pollen. This study also delves into evidence on plant-based (source and biological) interactions, which could indirectly influence the allergic potential of pollen. The current state of knowledge, open questions, and a brief overview of future research directions are outlined and discussed. We suggest that future studies should utilise a multi-disciplinary approach to better understand this complex system of pollen interactions that occur in nature.

Risk factors for the development of Thunderstorm-associated asthma among indigenous Ghanaians: A matched case-control study.

Objectives: Epidemic Thunderstorm asthma (TA) is a serious public health threat with a potential to overwhelm health systems. Being the first documented incidence in Ghana, we sought to determine whether the chronic respiratory risk factors for the development of TA as identified in other countries were similar or different from that in Ghana. Study design: A matched case-control study involving 41 cases and 82 controls was conducted in two conveniently selected health facilities in the Ashanti Region of Ghana. Methods: Data were collected from pre-existing patient records and included general demography, a history of allergies and a history of asthma. A chi-square and multiple logistic regression analysis were conducted to identify risk factors for the development of TA. Results: Overall, 53.7 % of the TA cases and 7.3 % of controls had a previous history of asthma (AOR = 4.53 p = 0.064, 95 % CI = 0.918-22.365). Also, 29.3 % of the cases and 1.2 % of the controls had a previous history of allergies (AOR = 12.48 p = 0.05, 95 % CI = 0.919-169.305). Conclusions: A previous history of allergy was a significant risk factor for TA. A previous history of asthma though associated with TA, was not a significant risk factor for its development. The recognition and awareness of risk factors for TA, by clinicians and health managers, is essential for health education, case management and preparation for the surge capacity occasioned by the event.

Extreme Weather Events and Asthma.

The objective of this article is to review recent literature on the implications of extreme weather events such as thunderstorms, wildfires, tropical cyclones, freshwater flooding, and temperature extremes in relationship to asthma symptoms. Several studies have shown worsening of asthma symptoms with thunderstorms, wildfires, tropical cyclones, freshwater flooding, and temperature extremes. In particular, thunderstorm asthma can be exacerbated by certain factors such as temperature, precipitation, and allergen sensitization. Therefore, it is imperative that the allergy and immunology community be aware of the health effects associated with these extreme weather events in order to educate patients and engage in mitigation strategies.

The perfect storm: temporal analysis of air during the world's most deadly epidemic thunderstorm asthma (ETSA) event in Melbourne.

BACKGROUND: There have been 26 epidemic thunderstorm asthma (ETSA) events worldwide, with Melbourne at the epicentre of ETSA with 7 recorded events, and in 2016 experienced the deadliest ETSA event ever recorded. Health services and emergency departments were overwhelmed with thousands requiring medical care for acute asthma and 10 people died. OBJECTIVES: This multidisciplinary study was conducted across various health and science departments with the aim of improving our collective understanding of the mechanism behind ETSA. DESIGN: This study involved time-resolved analysis of atmospheric sampling of the air for pollen and fungal spores, and intact and ruptured pollen compared with different weather parameters, pollution levels and clinical asthma presentations. METHODS: Time-resolved pollen and fungal spore data collected by Deakin AirWATCH Burwood, underwent 3-h analysis, to better reflect the 'before', 'during' and 'after' ETSA time points, on the days leading up to and following the Melbourne 2016 event. Linear correlations were conducted with atmospheric pollution data provided by the Environment Protection Authority (EPA) of Victoria, weather data sourced from Bureau of Meteorology (BOM) and clinical asthma presentation data from the Victorian Agency for Health Information (VAHI) of Department of Health. RESULTS: Counts of ruptured grass pollen grains increased 250% when the thunderstorm outflow reached Burwood. Increased PM10, high relative humidity, decreased temperature and low ozone concentrations observed in the storm outflow were correlated with increased levels of ruptured grass pollen. In particular, high ozone levels observed 6 h prior to this ETSA event may be a critical early indicator of impending ETSA event, since high ozone levels have been linked to increasing pollen allergen content and reducing pollen integrity, which may in turn contribute to enhanced pollen rupture. CONCLUSION: The findings presented in this article highlight the importance of including ruptured pollen and time-resolved analysis to forecast ETSA events and thus save lives.

Climate advocacy among Italian pediatric pulmonologists: A national survey on the effects of climate change on respiratory allergies.

Climate change (CC) is expected to negatively impact respiratory health due to air pollution and increased aeroallergen exposure. Children are among the most vulnerable populations due to high ventilation rates, small peripheral airways, and developing respiratory and immunological systems. To assess the current knowledge among Italian pediatric pulmonologists on the potential effects of CC on pediatric respiratory allergic diseases, a national survey was launched online from February 2020 to February 2021. The members of the Italian Pediatric Respiratory Society (SIMRI) were contacted by email and 117 questionnaires were returned (response rate 16.4%). 72.6% of respondents were females, 53.8% were academic pediatricians, 42.7% had been working >10 years. Most of the participants were aware of the potential health effects of CC and stated that they had noticed an increase in the incidence (90.6%) and severity (67.5%) of allergic respiratory diseases among their patients. About 61% and 41% of participants respectively felt that there had been an increase in the number of children sensitized to pollen and molds. When applying latent class analysis to identify the features characterizing participants with greater awareness and knowledge of CC-related health effects, two classes were identified: almost 60% of the participants were labeled as "poor knowledge" and those with greater awareness were older, had longer work experience, and were those using the Internet to gather information about CC. There is urgent need to increase pediatricians' awareness of the detrimental effects of CC on children's respiratory health and integrate them in the educational programs of healthcare professionals.

Prediction of airborne pollen concentrations by artificial neural network and their relationship with meteorological parameters and air pollutants.

After the early rainfall in the autumn of 2013, respiratory syndromes spread in the Khuzestan province of Iran with the most severity in Ahvaz. There have been recurring outbreaks in recent years. Considering that pollen-derived airborne allergens are regarded as key aeroallergens and the main cause of allergic rhinitis and asthma, this work aimed to forecast total pollen concentration in Ahvaz through an artificial neural network (ANN), followed by evaluating the pollen spatial distribution across the city and the association between pollen concentrations and environmental parameters. The utilized ANN in this work included an input layer with 13 parameters, a hidden layer of five neurons, and an output layer. Data were classified into training, validation, and testing sets. The ANN was implemented with 70% and 80% of data for training. The value of the correlation coefficient for the data validation of these two networks was 0.89 and 0.92, respectively. The results also indicated that despite the difference in the mean concentration of the pollens in various areas of Ahvaz, this difference was not statistically significant (P > 0.05). Furthermore, there was a negative correlation between the concentration of total pollen and relative humidity, precipitation, and air pressure. However, it had a positive correlation with temperature. Consequently, considering the logistical challenges of monitoring bioaerosols in the air, the ANN approach could predict total pollen concentrations. Therefore, in addition to measurements, the ANN technique can be a good tool to enable authorities to mitigate the impact of airborne pollen on people.

Climate change and allergies.

The climate crisis poses a major challenge to human health as well as the healthcare system and threatens to jeopardize the medical progress made in recent decades. However, addressing climate change may also be the greatest opportunity for global health in the 21st century. The climate crisis and its consequences, such as rising temperatures, forest fires, floods, droughts, and changes in the quality and quantity of food and water, directly and indirectly affect human physical and mental health. More intense and frequent heat waves and declining air quality have been shown to increase all-cause mortality, especially among the most vulnerable. Climate warming alters existing ecosystems and favors biological invasions by species that better tolerate heat and drought. Pathogen profiles are changing, and the transmission and spread of vector-borne diseases are increasing. The spread of neophytes in Europe, such as ragweed, is creating new pollen sources that increase allergen exposure for allergy sufferers. In addition, the overall milder weather, especially in combination with air pollution and increased CO2 levels, is changing the production and allergenicity of pollen. The phenomenon of thunderstorm asthma is also occurring more frequently. In view of the increasing prevalence of allergic diseases due to climate change, early causal immunomodulatory therapy is therefore all the more important. During a climate consultation, patients can receive individual advice on climate adaptation and resilience and the benefits of CO2 reduction-for their own and the planet's health. Almost 5% of all greenhouse gas emissions in Europe come from the healthcare sector. It thus has a central responsibility for a climate-neutral and sustainable transformation.

Climate Change Factors and the Aerobiology Effect.

There is clear evidence that climate change is occurring as there has been an acceleration of global temperatures since the mid-nineteenth century along with rising atmospheric carbon dioxide levels. It has been proposed that one of the most significant consequences of climate change on human health could be the impact on aeroallergens. Evidence from around globe has pointed to longer and more abundant pollen season associated with global warming. Additional studies have also suggested increased pollen allergenicity due to air pollution.