Kate R. Weinberger

CLIMATE CHANGE, AEROALLERGENS AND PEDIATRIC ALLERGIC DISEASE

The degree to which aeroallergens are contributing to the global increase in pediatric allergic disease is incompletely understood. We review the evidence that links climate change to changes in aeroallergens such as pollen and outdoor mold concentrations and, subsequently, aeroallergen association with pediatric allergic disease. We specifically explore the evidence on both the exacerbation and the development of allergic disease in children related to outdoor pollen and mold concentrations. Pediatric allergic diseases include atopic dermatitis or eczema, allergic rhinitis or hay fever, and some types of asthma in children, typically defined as < 18 years of age. We discuss how the timing of aeroallergen exposure both in utero and in childhood could be associated with allergies. We conclude that the magnitude and type of health impacts due to climate change will depend on improved understanding of the relationship between climatic variables, multiple allergen factors, and allergic disease. Improved public-health strategies such as adequate humidity control, optimum air filtration and ventilation, and improved anticipatory public-health messaging will be critical to adaptation.

The associations between daily spring pollen counts, over-the-counter allergy medication sales, and asthma syndrome emergency department visits in New York City, 2002-2012.

BackgroundMany types of tree pollen trigger seasonal allergic illness, but their population-level impacts on allergy and asthma morbidity are not well established, likely due to the paucity of long records of daily pollen data that allow analysis of multi-day effects. Our objective in this study was therefore to determine the impacts of individual spring tree pollen types on over-the-counter allergy medication sales and asthma emergency department (ED) visits.MethodsNine clinically-relevant spring tree pollen genera (elm, poplar, maple, birch, beech, ash, sycamore/London planetree, oak, and hickory) measured in Armonk, NY, were analyzed for their associations with over-the-counter allergy medication sales and daily asthma syndrome ED visits from patients’ chief complaints or diagnosis codes in New York City during March 1st through June 10th, 2002-2012. Multi-day impacts of pollen on the outcomes (0-3 days and 0-7 days for the medication sales and ED visits, respectively) were estimated using a distributed lag Poisson time-series model adjusting for temporal trends, day-of-week, weather, and air pollution. For asthma syndrome ED visits, age groups were also analyzed. Year-to-year variation in the average peak dates and the 10th-to-90th percentile duration between pollen and the outcomes were also examined with Spearman’s rank correlation.ResultsMid-spring pollen types (maple, birch, beech, ash, oak, and sycamore/London planetree) showed the strongest significant associations with both outcomes, with cumulative rate ratios up to 2.0 per 0-to-98th percentile pollen increase (e.g., 1.9 [95 % CI: 1.7, 2.1] and 1.7 [95 % CI: 1.5, 1.9] for the medication sales and ED visits, respectively, for ash). Lagged associations were longer for asthma syndrome ED visits than for the medication sales. Associations were strongest in children (ages 5-17; e.g., a cumulative rate ratio of 2.6 [95 % CI: 2.1, 3.1] per 0-to-98th percentile increase in ash). The average peak dates and durations of some of these mid-spring pollen types were also associated with those of the outcomes.ConclusionsTree pollen peaking in mid-spring exhibit substantive impacts on allergy, and asthma exacerbations, particularly in children. Given the narrow time window of these pollen peak occurrences, public health and clinical approaches to anticipate and reduce allergy/asthma exacerbation should be developed.

The Association of Tree Pollen Concentration Peaks and Allergy Medication Sales in New York City: 2003–2008

The impact of pollen exposure on population allergic illness is poorly characterized. We explore the association of tree pollen and over-the-counter daily allergy medication sales in the New York City metropolitan area. Dates of peak tree pollen (maple, oak, and birch) concentrations were identified from 2003 to 2008. Daily allergy medication sales reported to the city health department were analyzed as a function of the same-day and lagged tree pollen peak indicators, adjusting for season, year, temperature, and day of week. Significant associations were found between tree pollen peaks and allergy medication sales, with the strongest association at 2-day lag (excess sales of 28.7% (95% CI: 17.4–41.2) over the average sales during the study period). The cumulative effect over the 7-day period on and after the tree pollen peak dates was estimated to be 141.1% (95% CI: 79.4–224.1). In conclusion, tree pollen concentration peaks were followed by large increases in over-the-counter allergy medication sales.

Correlation Between Aeroallergen Levels and New Diagnosis of Eosinophilic Esophagitis in New York City.

Objective: The relation between food allergies and eosinophilic esophagitis (EoE) is well established. Aeroallergens may also contribute to the development of EoE; however, there are limited data to support or refute this hypothesis. The objectives of this pilot study were to determine whether there is a seasonal variation in the onset of symptoms and/or diagnosis of EoE and whether these variations correlate with a specific pollen concentration within New York City. Methods: We performed a retrospective chart review to identify all pediatric patients at New York Presbyterian Weill Cornell Medical Center diagnosed with EoE between 2002 and 2012. Sixty-six patients were identified and 28 were excluded. Cases were classified by both date of initial symptoms and date of histologic diagnosis. Pollen counts from a certified New York City counting station and the percentage of EoE cases were collated monthly and seasonally and compared. Results: There was a seasonal variation in onset of symptoms and diagnosis of EoE, with the highest number of patients reporting onset of symptoms of EoE in July to September, and those being diagnosed with EoE in October to December. There was a seasonal correlation between peak levels of grass pollen and peak onset of EoE symptoms, which were both highest in July to September. The diagnosis of EoE peaked one season later. Conclusions: The study findings suggest that there is a correlation between specific aeroallergens and both the onset of symptoms and time of diagnosis of patients with EoE.

New York City Panel on Climate Change 2015 ReportChapter 5: Public Health Impacts and Resiliency

Recent experience from Hurricane Sandy and high-temperature episodes has clearly demonstrated that the health of New Yorkers can be compromised by extreme coastal storms and heat events. Health impacts that can result from exposure to extreme weather events include direct loss of life, increases in respiratory and cardiovascular diseases, and compromised mental health. Other related health stressors—such as air pollution, pollen, and vector-borne, water-borne, and food-borne diseases—can also be influenced by weather and climate. Figure 5.1 illustrates the complex pathways linking extreme weather events to adverse health outcomes in New York City. New York City and the surrounding metropolitan region face potential health risks related to two principal climate hazards: (1) increasing temperatures and heat waves, and (2) coastal storms and flooding. The health impacts of these hazards depend in turn on myriad pathways, the most important of which are illustrated in the figure. Figure 5.1 Pathways linking climate hazards to health impacts in New York City. Although New York City is one of the best-prepared and most climate-resilient cities in the world, there remain significant potential vulnerabilities related to climate variability and change. As part of the NPCC2 process, a team of local climate and health specialists was mobilized to assess current vulnerabilities and to identify strategies that could enhance the resilience of New York City to adverse health impacts from climate events. The goal was to highlight some of the important climate-related health challenges that New York City is currently facing or may face in the future due to climate variability and change, based on emerging scientific understanding. As indicated in Figure 5.1, health vulnerabilities can be magnified when critical infrastructure is compromised. Critical infrastructure is a highly complex, heterogeneous, and interdependent mix of facilities, systems, and functions that are vulnerable to a wide variety of threats, including extreme weather events. For example, delivery of electricity to households depends on a multi-faceted electrical grid system that is susceptible to blackouts that can occur during heat waves. These, in turn, can expose people to greater risk of contact with exposed wires or to greater heat stress due to failure of air conditioning. Understanding and predicting the impacts that extreme weather events may have on health in New York City require careful analysis of these interactions. Two recent plans to enhance climate resiliency in New York City have been released. A Stronger, More Resilient New York (City of New York, 2013) was developed in the aftermath of Hurricane Sandy by a task force of representatives from City agencies and consultants. This plan was informed by a detailed analysis of the impacts of Hurricane Sandy on infrastructure and the built environment and by the NPCC’s updated 2013 climate projections for the New York metropolitan region. It includes more than 250 initiatives and actionable recommendations addressing 14 domains of the built environment and infrastructure including the healthcare system and several other domains relevant to protecting public health. In addition, the 2014 New York City Hazard Mitigation Plan (HMP) (City of New York, 2014), developed by the NYC Office of Emergency Management in collaboration with the Department of City Planning, updated the 2009 HMP and assesses risks from multiple hazards that threaten New York City. These include but are not limited to several climate-related hazards such as coastal storms and heat waves, and it lays out comprehensive strategies and plans to address these hazards. Many of the measures recommended by A Stronger, More Resilient New York and the HMP have already been implemented, are in progress, or are planned (City of New York, 2013; 2014). This chapter does not include a detailed review of these plans, which would be beyond the expertise and charge of the contributors. Nonetheless, the recommendations in this chapter do broadly support the plans laid out in A Stronger, More Resilient New York and the 2014 HMP, and these are referenced at several points where they are especially relevant. Here we focus on summarizing and synthesizing the emerging scientific knowledge on climate-related health hazards, knowledge that can inform ongoing preparedness planning. Key terms related to climate variability and change as they are applied in the health sector are defined in Box 5.1. This is followed by sections describing health risks, vulnerabilities, and resilience strategies for coastal storms and extreme heat events. We then briefly discuss the interactions of climate change with air pollution, pollen, vector-borne diseases, and water- and food-borne diseases. We conclude with recommendations for research and resiliency planning. Box 5.1 Definitions of key cross-cutting terms in the health context Adaptation Initiatives and measures to reduce the vulnerability of natural and human systems against actual or expected climate change effects. Various types of adaptation exist, such as anticipatory and reactive, private and public, and autonomous and planned. For health, physiological adaptation is also relevant.

Levels and determinants of tree pollen in New York City

Exposure to allergenic tree pollen is a risk factor for multiple allergic disease outcomes. Little is known about how tree pollen levels vary within cities and whether such variation affects the development or exacerbation of allergic disease. Accordingly, we collected integrated pollen samples at uniform height at 45 sites across New York City during the 2013 pollen season. We used these monitoring results in combination with adjacent land use data to develop a land use regression model for tree pollen. We evaluated four types of land use variables for inclusion in the model: tree canopy, distributed building height (a measure of building volume density), elevation, and distance to water. When included alone in the model, percent tree canopy cover within a 0.5 km radial buffer explained 39% of the variance in tree pollen (1.9% increase in tree pollen per one-percentage point increase in tree canopy cover, P<0.0001). The inclusion of additional variables did not improve model fit. We conclude that intra-urban variation in tree canopy is an important driver of tree pollen exposure. Land use regression models can be used to incorporate spatial variation in tree pollen exposure in studies of allergic disease outcomes.

Climate, Air Quality, and Allergy: Emerging Methods for Detecting Linkages

Both anthropogenic and naturally occurring air contaminants can be influenced by climate variability and change and in turn may have important implications for human health. Anthropogenic ozone (O3) is a pollutant that poses serious health concerns and whose formation in the lower atmosphere depends on temperature and sunlight as well as other meteorologic parameters. Airborne pollens released by trees, grasses, and weeds are responsible for considerable respiratory morbidity and are also influenced by climate factors, as well as by changing carbon dioxide concentrations. Here we report recent findings from a research team in New York City (NYC) that has been investigating interactions between climate, air quality, and human health. The first case study we cover made projections of future O3 and temperature levels at the county level in the NYC metro area under alternative climate change scenarios, and then translation of these changes into mortality impacts using exposure–response equations derived from historical data in NYC. Findings suggested that heat-related mortality could grow in importance over future decades as compared with O3-related mortality, and that health effects could be reduced by policies that limit greenhouse gas emissions. In the second case study, we analyzed the effects of spring tree pollen peaks on sales of over-the-counter allergy medications in NYC over a 6-year period. We found a significant effect which had a maximum at lag 2, indicating that tree pollen peaks precede spikes in medication sales by approximately 2 days. Both sets of findings highlight the value of climate and health research as a tool for policy makers concerned with anticipating and preventing adverse health impacts related to climate change.