Thunderstorms, Pollen, and Severe Asthma in a Midwestern, USA, Urban Environment, 2007-2018

Sex and age characteristics of thunderstorm asthma emergency department visits

Severe asthma has been shown to occur in the combined presence of high pollen and thunderstorm conditions, also known as 'thunderstorm asthma.' First studied as severe epidemic events, recent longitudinal work studied less dramatic but more frequent occurrences. We explore thunderstorm asthma-related emergency department visits in the Minneapolis-St. Paul metropolitan area and evaluated risk differences by sex and age. We define a thunderstorm asthma exposure event as the daily occurrence of 2 or more lightning strikes during high pollen periods, and use daily counts of asthma-related emergency department visits to estimate relative and absolute risk of severe asthma during thunderstorm asthma events for the full population and for sex and age subgroups. The overall population had a 1.06 (95 % CI: 1.02, 1.09) times higher risk of asthma-related ED visits during thunderstorm asthma events compared to days without thunderstorm asthma events. Children under 18 show no higher risk (RR 1.02; 95 % CI: 0.97 1.08), but adults 18-44 years (RR 1.08; 95 % CI: 1.02, 1.13) and 45 and up (RR 1.08; 95 % CI 1.02, 1.15) show higher relative risk. Absolute risk measures show similar patterns to the age and sex results, but age-sex subgroups show more variation in absolute vs relative risk. Our results support an association between ED visits and thunderstorm asthma and provide evidence of varying risks by sex across the life course. These differences in risk have implications for clinical treatment of this allergic type of asthma and for future research into this poorly recognized environmental exposure. Plain Language Summary: Recent research has highlighted the existence of Thunderstorm asthma events, a phenomenon in which pollen grains rupture in the conditions that occur with a thunderstorm, releasing subpollen particles that are capable of triggering severe asthma in susceptible populations. Where severe asthma is a disease that usually impacts children, we find in this study that asthma ED visits associated with thunderstorm asthma events more frequently impact adults, particularly males 18-44 and females 45 and up.

The Joint Effects of Thunderstorms and Power Outages on Respiratory-Related Emergency Visits and Modifying and Mediating Factors of This Relationship

BACKGROUND

While limited studies have evaluated the health impacts of thunderstorms and power outages (POs) separately, few have assessed their joint effects. We aimed to investigate the individual and joint effects of both thunderstorms and POs on respiratory diseases, to identify disparities by demographics, and to examine the modifications and mediations by meteorological factors and air pollution.

METHODS

Distributed lag nonlinear models were used to examine exposures during three periods (i.e., days with both thunderstorms and POs, thunderstorms only, and POs only) in relation to emergency department visits for respiratory diseases (2005-2018) compared to controls (no thunderstorm/no PO) in New York State (NYS) while controlling for confounders. Interactions between thunderstorms and weather factors or air pollutants on health were assessed. The disparities by demographics and seasons and the mediative effects by particulate matter with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ) and relative humidity (RH) were also evaluated.

RESULTS

Thunderstorms and POs were independently associated with total and six subtypes of respiratory diseases in NYS [highest risk ratio (RR) = 1.12; 95% confidence interval (CI): 1.08, 1.17], but the impact was stronger when they co-occurred (highest RR = 1.44; 95% CI: 1.22, 1.70), especially during grass weed, ragweed, and tree pollen seasons. The stronger thunderstorm/PO joint effects were observed on chronic obstructive pulmonary diseases, bronchitis, and asthma (lasted 0-10 d) and were higher among residents who lived in rural areas, were uninsured, were of Hispanic ethnicity, were 6-17 or over 65 years old, and during spring and summer. The number of comorbidities was significantly higher by 0.299-0.782/case. Extreme cold/heat, high RH, PM 2.5 , and ozone concentrations significantly modified the thunderstorm-health effect on both multiplicative and additive scales. Over 35% of the thunderstorm effects were mediated by PM 2.5 and RH.

CONCLUSION

Thunderstorms accompanied by POs showed the strongest respiratory effects. There were large disparities in thunderstorm-health associations by demographics. Meteorological factors and air pollution levels modified and mediated the thunderstorm-health effects. https://doi.org/10.1289/EHP13237.

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.

Pulmonary Function Tests in Thunderstorm-associated Respiratory Symptoms: A Cross-sectional Study

Background

Epidemic thunderstorm asthma is an observed increase in cases of acute bronchospasm following thunderstorms. This study aimed to compare the frequency of obstructive airway disease or bronchial hyperresponsiveness in subjects with thunderstorm-associated respiratory symptoms with subjects with similar symptoms presented at other times.

Methods

A cross-sectional study from June to November of 2013 was conducted on subjects with thunderstorm-associated respiratory symptoms living in Ahvaz City, Iran. Thunderstorm-associated subjects were presented with asthmatic symptoms in thunderstorms, and other patients presented with similar symptoms at other times. Baseline spirometry was performed on patients to examine the presence of obstructive airway disease. In all patients with normal spirometry, a provocation test was applied. A comparison of qualitative and quantitative variables was made using the Chi-square and independent t test, respectively. All analyses were carried out using SPSS Statistics Version 22. A P value less than 0.05 was considered statistically significant.

Results

Out of 584 subjects, 300 and 284 participants were in thunderstorm-associated and non-thunderstorm-associated groups, respectively. After the final analysis, 87 (30.6%) and 89 (33.3%) of the thunderstorm-associated subjects and non-thunderstorm-associated group, respectively, had pieces of evidence of airflow limitation (P=0.27). Among the patients with normal spirometry, 161 (81.72%) of the thunderstorm-associated patients and 100 (56.17%) patients of the non-thunderstorm-associated symptoms group had a positive methacholine challenge test result (P<0.001).

Conclusion

Most of the patients with thunderstorm-associated respiratory symptoms had no obvious evidence of airflow limitation in spirometry.

Thunder storm mortality: Issues of medicolegal concern

Thunderstorms refer to atmospheric disturbances that are associated with electrical discharges in the form of lightning, with acoustic effects from thunder. They involve the rapid upward movement of warm, moist air which then cools and condenses creating typical cumulonimbus clouds with precipitation. Thunderstorms range in severity but are usually associated with heavy rains, winds and sometimes sleet, hail and snow. If the intensity of a storm increases there may be tornadoes or cyclones. In cases with lightning strikes and minimal or no rain there is an associated risk for the development of quite devastating wild (bush) fires. Lightning strikes may also be associated with the development, or an exacerbation, of potentially lethal natural cardiac or respiratory diseases.

Extreme weather and asthma: a systematic review and meta-analysis

BACKGROUND

Climate change's influence on extreme weather events poses a significant threat to the morbidity and mortality of asthma patients. The aim of this study was to examine associations between extreme weather events and asthma-related outcomes.

METHODS

A systematic literature search for relevant studies was performed using the PubMed, EMBASE, Web of Science and ProQuest databases. Fixed-effects and random-effects models were applied to estimate the effects of extreme weather events on asthma-related outcomes.

RESULTS

We observed that extreme weather events were associated with increasing risks of general asthma outcomes with relative risks of 1.18-fold for asthma events (95% CI 1.13-1.24), 1.10-fold for asthma symptoms (95% CI 1.03-1.18) and 1.09-fold for asthma diagnoses (95% CI 1.00-1.19). Extreme weather events were associated with increased risks of acute asthma exacerbation with risk ratios of asthma emergency department visits of 1.25-fold (95% CI 1.14-1.37), of asthma hospital admissions of 1.10-fold (95% CI 1.04-1.17), of asthma outpatient visits of 1.19-fold (95% CI 1.06-1.34) and of asthma mortality of 2.10-fold (95% CI 1.35-3.27). Additionally, an increase in extreme weather events increased risk ratios of asthma events by 1.19-fold in children and 1.29-fold in females (95% CI 1.08-1.32 and 95% CI 0.98-1.69, respectively). Thunderstorms increased the risk ratio of asthma events by 1.24-fold (95% CI 1.13-1.36).

CONCLUSIONS

Our study showed that extreme weather events more prominently increased the risk of asthma morbidity and mortality in children and females. Climate change is a critical concern for asthma control.

Precipitation and Adolescent Respiratory Health in the Northeast United States

Rationale: With more frequent and intense precipitation events across the globe due to a changing climate, there is a need to understand the relationship between precipitation and respiratory health. Precipitation may trigger asthma exacerbations, but little is known about how precipitation affects lung function and airway inflammation in early adolescents. Objectives: To determine if short-term precipitation exposure is associated with lung function and airway inflammation in early adolescents and if ever having a diagnosis of asthma modifies associations of precipitation with lung function and airway inflammation. Methods: In a prospective prebirth cohort, Project Viva, that included 1,019 early adolescents born in the northeastern United States, we evaluated associations of 1-, 2-, 3-, and 7-day moving averages of precipitation in the preceding week and forced expiratory volume in 1 second, forced vital capacity, and fractional exhaled nitric oxide (FeNO) using linear regression. We used log-transformed FeNO with effect estimates presented as percentage change. We adjusted for maternal education and household income at enrollment; any smoking in the home in early adolescence; child sex, race/ethnicity, and ever asthma diagnosis; and age, height, weight, date, and season (as sine and cosine functions of visit date) at the early adolescent visit and moving averages for mean daily temperature (same time window as exposure). Results: In fully adjusted linear models, 3- and 7-day moving averages for precipitation were positively associated with FeNO but not lung function. Every 2-mm increase in the 7-day moving average for precipitation was associated with a 4.0% (95% confidence interval, 1.1, 6.9) higher FeNO. There was evidence of effect modification by asthma status: Precipitation was associated with lower forced vital capacity and higher FeNO among adolescents with asthma. We also found that outdoor aeroallergen sensitization (immunoglobulin E against common ragweed, oak, ryegrass, or silver birch) modified associations of precipitation with FeNO, with higher FeNO in sensitized adolescents compared with nonsensitized adolescents. The associations of precipitation with FeNO were not explained by relative humidity or air pollution exposure. Conclusions: We found that greater short-term precipitation may trigger airway inflammation in adolescents, particularly among those with asthma.