Asthma admissions and thunderstorms: a study of pollen, fungal spores, rainfall, and ozone

Abstract

Asthma admissions have been reported to increase during thunderstorms. In some cases, this has been attributed to rises in pollen or fungal spore counts occurring alone or in combination with rainfall. We tested the hypothesis that thunderstorms in general are associated with asthma admissions, and investigated the possible roles of pollen, fungal spores, ozone, and other meteorological factors. We obtained data on multiple pollen and fungal spore counts, rainfall, temperature, ambient ozone concentrations, and asthma admissions for 32 dates when lightning strikes were recorded in the Cardiff/Newport area, and 64 matched dates in previous and subsequent years. Poisson regression models were used to investigate associations between admissions and proposed causative environmental factors. The number of asthma admissions was greater on days with thunderstorms than on control days (p<0.001). There were no associations or interactions between admissions and any pollen or fungal spore counts or rainfall. After adjusting for thunderstorms, there was an independent association between increasing ozone concentration, when temperature was included in the model, and increasing admissions (p=0.02). Asthma admissions are increased during thunderstorms. The effect is more marked in warmer weather, and is not explained by increases in grass pollen, total pollen or fungal spore counts, nor by an interaction between these and rainfall. There was an independent, positive association between ozone concentrations and asthma admissions.

Epidemic asthma and the role of the fungal mold Alternaria alternata

“…In neither study were there adequate data on environmental levels of grass pollen or fungal spores at the time of the asthma outbreak. Ozone causes bronchial hyperresponsiveness, 27 and levels of ozone were very high before the thunderstorm on July 29. Taylor and Jonsson 28 have proposed a mechanism by which updraughts entrain pollen grains into the high humidity of a cloud base, where the grains rupture, and downdraughts transport the fragments to ground level in dry cold outflows extending about 5 km ahead of the rainfall.…”

Health effects of air pollution

“…68,69 The interesting observation that increased asthma admissions were associated with thunderstorms was originally attributed to peak fungal spore counts preceding or during the weather front but not to concomitant increases in air pollutants. [70][71][72][73][74] Several more recent studies failed to show an association with thunderstorms but instead found a positive association between asthma admissions and higher levels of ozone at these times. As previously discussed, controlled challenge studies all have demonstrated that inhaled ozone, NO 2 , and SO 2 , individually or in combination, might enhance the airway response to inhaled allergens, thereby inducing asthma exacerbations.…”

The spatiotemporal distributions and determinants of ambient fungal spores in the Greater Taipei area

“…Bioaerosols are abundant in nature, especially fungi and pollen (Macher, 1999;Monn and Koren, 1999;Jones and Harrison, 2004). The associations between exposure to ambient bioaerosols and adverse health effects, such as exacerbation of asthma, allergies, and respiratory diseases, have been reported (Anderson et al, 2001;Burge, 2001;Burge and Rogers, 2000;Cakmak et al, 2002;Peden and Reed, 2010).…”