Investigating Airborne Pollen Grains and Fungal Spores that Might be Related to Thunderstorm Asthma Attacks

Pollen and fungi cause acute respiratory attacks every year around the world. Thunderstorm asthma attacks hospitalized thousands of people in Ahvaz during the first rain meanwhile pollen grains and fungal spores are the strongest reasons for this phenomenon. Therefore, in the current study different types of pollen grains and fungal spores were collected by Burkard pump during autumn and winter of 2016–2017 and 2017–2018. The analysis characterized pollen grains and fungal spores with homogeneous distributions during the sampling periods. A fungal spore called Curvularia genous showed the most significant correlation with daily rainfall. Daily rainfall and Curvularia genous spores reached their peak, simultaneously. During the first rain, it was considerably higher than other days of the study period, especially in contrast with the second and third rainy days. Also, reverse wind direction—blowing from south—during the respiratory outbreaks may reveal the synergistic effect with air pollutants from heavy industries. We concluded that the autumnal respiratory outbreak in Ahvaz might be triggered by a mixture of fungal spores (especially Curvularia genous), industrial air pollutants, and pollen grains of the predominant tree of Ahvaz urban green infrastructure which is Conocarpus erectus. Highlights A homogeneous distribution for weekly fungal spores integrals during autumn was observed. Reverse wind direction during the event showed the synergistic effects of heavy industries. Simultaneously peak of daily rainfall and fungal spores was observed. Juliflora , Corovularia , and Conocarpus could be posed as bioallergens.