Climate change and allergic diseases

Comprehensive Study on Key Pollen Allergens

Pollens are typically the primary reason for seasonal hypersensitivity caused in many people that are released by a hundred different species of plants for fertilization. Not all pollens are the same or have the same effect on human beings, there are those worse than others. The human body works out on a defence mechanism by creating certain reactions against those offensive pollens as a response by the immune system. The allergic reactions include sneezing, coughing, wheezing, itching, red-watery swelled eyes, runny nose, inflammation in the nasal passage frequently leading to rhinitis, asthma, skin irritation, and other respiratory disorders. This study is intended to acquire knowledge about a few plants with high allergenic properties along with their major allergens. It is evident that the pollination of the plants varies from season to season as it depends on various factors such as species, weather, and geographical location. Understanding these high allergenic plants with respect to their varying factors and cross-reacting properties is the purpose of this study. It is an effort to obtain deeper insights into these common pollen offenders.

Occupational risks and their implications for the health of poultry farmers

BACKGROUND

Poultry activity exposes workers to accidents and unhealthy conditions with physical, chemical, biological, ergonomic and psychological risks.

OBJECTIVE

The objective was to list risk factors in poultry farms in operational, behavioral, and environmental aspects.

METHODS

We evaluated poultry farm workers through quantitative and qualitative analysis applying a semi-structured online questionnaire containing 58 questions to identify risks in the workplace and health implications.

RESULTS

Most facilities were air-conditioned, workers performed their activities in a totally closed environment, with low light (1 to 10 lux), for more than 40 h/wk. Regarding accidents, 61%of workers claimed to have suffered some type of accident, 34%claimed to not use personal protection equipment, and 41%felt unable to perform their activities at some time due to health problems; handling animals and animal waste were the most significant biological risks; dust and ammonia corresponded to the most significant chemical risks; and electric shock, burns, and heat exposure were the most significant physical/accident risks.

CONCLUSIONS

Workers expose themselves daily to physical, chemical, biological, psychosocial, and ergonomic risks. These exposures often lead to symptoms such as stress, headache, eye and mucous membrane disorders, respiratory diseases, back and muscle pain, depression, and symptoms often associated with Sick Building Syndrome.

Disentangling the effects of feedback structure and climate on Poaceae annual airborne pollen fluctuations and the possible consequences of climate change

Pollen allergies are the most common form of respiratory allergic disease in Europe. Most studies have emphasized the role of environmental processes, as the drivers of airborne pollen fluctuations, implicitly considering pollen production as a random walk. This work shows that internal self-regulating processes of the plants (negative feedback) should be included in pollen dynamic systems in order to give a better explanation of the observed pollen temporal patterns. This article proposes a novel methodological approach based on dynamic systems to investigate the interaction between feedback structure of plant populations and climate in shaping long-term airborne Poaceae pollen fluctuations and to quantify the effects of climate change on future airborne pollen concentrations. Long-term historical airborne Poaceae pollen data (30 years) from Cordoba city (Southern Spain) were analyzed. A set of models, combining feedback structure, temperature and actual evapotranspiration effects on airborne Poaceae pollen were built and compared, using a model selection approach. Our results highlight the importance of first-order negative feedback and mean annual maximum temperature in driving airborne Poaceae pollen dynamics. The best model was used to predict the effects of climate change under two standardized scenarios representing contrasting temporal patterns of economic development and CO2 emissions. Our results predict an increase in pollen levels in southern Spain by 2070 ranging from 28.5% to 44.3%. The findings from this study provide a greater understanding of airborne pollen dynamics and how climate change might impact the future evolution of airborne Poaceae pollen concentrations and thus the future evolution of related pollen allergies.

Meteorological conditions, climate change, new emerging factors, and asthma and related allergic disorders. A statement of the World Allergy Organization

The prevalence of allergic airway diseases such as asthma and rhinitis has increased dramatically to epidemic proportions worldwide. Besides air pollution from industry derived emissions and motor vehicles, the rising trend can only be explained by gross changes in the environments where we live. The world economy has been transformed over the last 25 years with developing countries being at the core of these changes. Around the planet, in both developed and developing countries, environments are undergoing profound changes. Many of these changes are considered to have negative effects on respiratory health and to enhance the frequency and severity of respiratory diseases such as asthma in the general population.

Increased concentrations of greenhouse gases, and especially carbon dioxide (CO₂), in the atmosphere have already warmed the planet substantially, causing more severe and prolonged heat waves, variability in temperature, increased air pollution, forest fires, droughts, and floods – all of which can put the respiratory health of the public at risk. These changes in climate and air quality have a measurable impact not only on the morbidity but also the mortality of patients with asthma and other respiratory diseases. The massive increase in emissions of air pollutants due to economic and industrial growth in the last century has made air quality an environmental problem of the first order in a large number of regions of the world. A body of evidence suggests that major changes to our world are occurring and involve the atmosphere and its associated climate. These changes, including global warming induced by human activity, have an impact on the biosphere, biodiversity, and the human environment. Mitigating this huge health impact and reversing the effects of these changes are major challenges.

This statement of the World Allergy Organization (WAO) raises the importance of this health hazard and highlights the facts on climate-related health impacts, including: deaths and acute morbidity due to heat waves and extreme meteorological events; increased frequency of acute cardio-respiratory events due to higher concentrations of ground level ozone; changes in the frequency of respiratory diseases due to trans-boundary particle pollution; altered spatial and temporal distribution of allergens (pollens, molds, and mites); and some infectious disease vectors. According to this report, these impacts will not only affect those with current asthma but also increase the incidence and prevalence of allergic respiratory conditions and of asthma. The effects of climate change on respiratory allergy are still not well defined, and more studies addressing this topic are needed. Global warming is expected to affect the start, duration, and intensity of the pollen season on the one hand, and the rate of asthma exacerbations due to air pollution, respiratory infections, and/or cold air inhalation, and other conditions on the other hand.

Allergenic pollen season variations in the past two decades under changing climate in the United States

Many diseases are linked with climate trends and variations. In particular, climate change is expected to alter the spatiotemporal dynamics of allergenic airborne pollen and potentially increase occurrence of allergic airway disease. Understanding the spatiotemporal patterns of changes in pollen season timing and levels is thus important in assessing climate impacts on aerobiology and allergy caused by allergenic airborne pollen. Here, we describe the spatiotemporal patterns of changes in the seasonal timing and levels of allergenic airborne pollen for multiple taxa in different climate regions at a continental scale. The allergenic pollen seasons of representative trees, weeds and grass during the past decade (2001-2010) across the contiguous United States have been observed to start 3.0 [95% Confidence Interval (CI), 1.1-4.9] days earlier on average than in the 1990s (1994-2000). The average peak value and annual total of daily counted airborne pollen have increased by 42.4% (95% CI, 21.9-62.9%) and 46.0% (95% CI, 21.5-70.5%), respectively. Changes of pollen season timing and airborne levels depend on latitude, and are associated with changes of growing degree days, frost free days, and precipitation. These changes are likely due to recent climate change and particularly the enhanced warming and precipitation at higher latitudes in the contiguous United States.

Paradoxical increase of IgE binding components during allergen-specific immunotherapy in pollinosis patients

Allergen-specific immunotherapy (SIT) reduces allergen specific IgE (sIgE) levels and achieves clinical and immunological tolerance by modulating innate and adaptive immunological responses. Increased temperature and CO2 concentrations caused by climate changes contribute to an increase of pollen count and allergenicity that influences clinical SIT outcomes. In this study, we investigated the changes of IgE binding components to tree and weed pollens in pollinosis patients who showed a paradoxical increase of serum sIgE level during pollen-SIT. We enrolled nine patients who showed an increasing pattern of serum sIgE level to alder, birch, ragweed and mugwort pollens by enzyme-linked immunosorbant assay. IgE immunoblot analysis confirmed the intensification or new generation of major IgE binding components that could be induced by climate change. The findings suggest that the regular monitoring of sIgE levels and symptom changes is required to improve the clinical outcomes of SIT in patients undergoing SIT for tree and weed pollens.

Associations between ozone, PM2.5, and four pollen types on emergency department pediatric asthma events during the warm season in New Jersey: a case-crossover study

BACKGROUND

Asthma is one of the most common chronic diseases among school-aged children in the United States. Environmental respiratory irritants exacerbate asthma among children. Understanding the impact of a variety of known and biologically plausible environmental irritants and triggers among children in New Jersey - ozone, fine particulate matter (PM2.5), tree pollen, weed pollen, grass pollen and ragweed - would allow for informed public health interventions.

METHODS

Time-stratified case-crossover design was used to study the transient impact of ozone, PM2.5 and pollen on the acute onset of pediatric asthma. Daily emergency department visits were obtained for children aged 3-17 years with a primary diagnosis of asthma during the warm season (April through September), 2004-2007 (inclusive). Bi-directional control sampling was used to select two control periods for each case for a total of 65,562 inclusion days. Since the period of exposure prior to emergency department visit may be the most clinically relevant, lag exposures were investigated (same day (lag0), 1, 2, 3, 4, and 5 as well as 3-day and 5-day moving averages). Multivariable conditional logistic regression controlling for holiday, school-in-session indicator, and 3-day moving average for temperature and relative humidity was used to examine the associations. Odds ratios are based on interquartile range (IQR) increases or 10 unit increases when IQR ranges were narrow. Single-pollutant models as well as multipollutant models were examined. Stratification on gender, race, ethnicity and socioeconomic status was explored.

RESULTS

The associations with ozone and PM2.5 were strongest on the same day (lag0) of the emergency department visit (RR IQR=1.05, 95% CI 1.04-1.06) and (RR IQR=1.03, 95% CI 1.02-1.04), respectively, with a decreasing lag effect. Tree and weed pollen were associated with pediatric ED visits; the largest magnitudes of association was with the 5-day average (RR IQR=1.23, 95% CI 1.21-1.25) and (RR 10=1.13, 95% CI 1.12-1.14), respectively. Grass pollen was only minimally associated with the outcome while ragweed had a negative association.

CONCLUSIONS

The ambient air pollutant ozone is associated with increases in pediatric emergency department asthma visits during the warm weather season. The different pollen types showed different associations with the outcome. High levels of tree pollen appear to be an important risk factor in asthma exacerbations.

Heterogeneity in ragweed pollen exposure is determined by plant composition at small spatial scales

Pollen allergies are one of the most common health problems in the United States and over 20% of Americans are sensitized to the pollen produced by common ragweed (Ambrosia artemisiifolia L.). Despite the importance of allergenic pollen to public health, no research has linked land use and plant populations to spatial heterogeneity in airborne pollen concentrations. In order to quantify these relationships and elucidate the processes which lead to pollen exposure, we surveyed ragweed stem density in Detroit (Michigan, USA) as a function of land use. We then deployed 34 pollen collectors throughout the city and recorded ragweed cover in the immediate vicinity of each pollen collector. We found that ragweed populations were highest in vacant lots, a common land cover type in Detroit. Because ragweed population density was so strongly correlated to vacant lots, for which spatially explicit data were available, we were able to investigate whether observed ragweed pollen concentrations were a function of land use at the spatial scales of 10 m and 1 km. Both relationships were significant, and the combination of these two variables predicts a large portion of airborne ragweed pollen concentrations (R(2)=0.48). These results emphasize the important role of pollen production within the urban environment and show that management of allergenic pollen producing plants must be considered at multiple spatial scales. Our findings also demonstrate that there is too much spatial heterogeneity for a pollen collector at any given site to portray the allergenic pollen load experienced by different individuals within the same city. Finally, we discuss how spatial correlations between socio-economic status, vacant lots, and ragweed could help to explain the disproportionate amount of allergies and ragweed sensitization experienced by low income and minority populations in Detroit.

Impact of ambient humidity on child health: a systematic review

BACKGROUND AND OBJECTIVES

Changes in relative humidity, along with other meteorological factors, accompany ongoing climate change and play a significant role in weather-related health outcomes, particularly among children. The purpose of this review is to improve our understanding of the relationship between ambient humidity and child health, and to propose directions for future research.

METHODS

A comprehensive search of electronic databases (PubMed, Medline, Web of Science, ScienceDirect, OvidSP and EBSCO host) and review of reference lists, to supplement relevant studies, were conducted in March 2013. All identified records were selected based on explicit inclusion criteria. We extracted data from the included studies using a pre-designed data extraction form, and then performed a quality assessment. Various heterogeneities precluded a formal quantitative meta-analysis, therefore, evidence was compiled using descriptive summaries.

RESULTS

Out of a total of 3797 identified records, 37 papers were selected for inclusion in this review. Among the 37 studies, 35% were focused on allergic diseases and 32% on respiratory system diseases. Quality assessment revealed 78% of the studies had reporting quality scores above 70%, and all findings demonstrated that ambient humidity generally plays an important role in the incidence and prevalence of climate-sensitive diseases among children.

CONCLUSIONS

With climate change, there is a significant impact of ambient humidity on child health, especially for climate-sensitive infectious diseases, diarrhoeal diseases, respiratory system diseases, and pediatric allergic diseases. However, some inconsistencies in the direction and magnitude of the effects are observed.

Rupatadine inhibits inflammatory mediator release from human laboratory of allergic diseases 2 cultured mast cells stimulated by platelet-activating factor

BACKGROUND

Mast cells are involved in allergy and inflammation by the secretion of multiple mediators, including histamine, cytokines, and platelet-activating factor (PAF), in response to different triggers, including emotional stress. PAF has been associated with allergic inflammation, but there are no clinically available PAF inhibitors.

OBJECTIVE

To investigate whether PAF could stimulate human mast cell mediator release and whether rupatadine (RUP), a dual histamine-1 and PAF receptor antagonist, could inhibit the effect of PAF on human mast cells.

METHODS

Laboratory of allergic diseases 2 cultured mast cells were stimulated with PAF (0.001, 0.01, and 0.1 μmol/L) and substance P (1 μmol/L) with or without pretreatment with RUP (2.5 and 25 μmol/L), which was added 10 minutes before stimulation. Release of β-hexosaminidase was measured in supernatant fluid by spectrophotoscopy, and histamine, interleukin-8, and tumor necrosis factor were measured by enzyme-linked immunosorbent assay.

RESULTS

PAF stimulated a statistically significant release of histamine, interleukin-8, and tumor necrosis factor (0.001-0.1 μmol/L) that was comparable to that stimulated by substance P. Pretreatment with RUP (25 μmol/L) for 10 minutes inhibited this effect. In contrast, pretreatment of laboratory of allergic diseases 2 cells with diphenhydramine (25 μmol/L) did not inhibit mediator release, suggesting that the effect of RUP was not due to its antihistaminic effect.

CONCLUSION

PAF stimulates human mast cell release of proinflammatory mediators that is inhibited by RUP. This action endows RUP with additional properties in treating allergic inflammation.

The mountain cedar model in clinical trials of seasonal allergic rhinoconjunctivitis

BACKGROUND

Clinical trials of seasonal allergic rhinoconjunctivitis use the mountain cedar (Juniperus ashei) season as the predominate model.

OBJECTIVE

To evaluate clinical trials of rhinoconjunctivitis using mountain cedar, to present analysis of pollen counts during 18 seasons, and to discuss the model.

METHODS

The medical literature was searched for clinical trials performed using mountain cedar either in or out of season. Pollen counts were recorded and analyzed for the duration of 18 seasons.

RESULTS

Thirty-eight trials were identified. Of these, 1 evaluated onset of allergy, 8 were immunotherapy trials, 28 were pharmaceutical clinical trials, and 1 studied symptoms elicited in a pollen challenge chamber trial. Many generic equivalency trials are unreported. In the 18 years of counts in the Texas Hill Country, a dependable and intense pollen density was present in every season. The combination of dependable seasons without confounding pollens, the large number of allergic patients, and the ability to concentrate resources in one geographic area has made mountain cedar allergy a mainstay for therapeutic trials for allergic rhinoconjunctivitis.

CONCLUSION

Mountain cedar allergy presents a dependable and durable model of allergic rhinoconjunctivitis.

Climate change and allergic disease

Allergies are prevalent throughout the United States and impose a substantial quality of life and economic burden. The potential effect of climate change has an impact on allergic disorders through variability of aeroallergens, food allergens and insect-based allergic venoms. Data suggest allergies (ocular and nasal allergies, allergic asthma and sinusitis) have increased in the United States and that there are changes in allergies to stinging insect populations (vespids, apids and fire ants). The cause of this upward trend is unknown, but any climate change may induce augmentation of this trend; the subspecialty of allergy and immunology needs to be keenly aware of potential issues that are projected for the near and not so distant future.