Environmental conditions and childhood asthma in LISBON. An exploratory analysis for autumn thunderstorms

Abstract

Asthma attacks triggered by thunderstorms have been described in several countries. The rises in pollen concentrations, attributed to atmospheric electrical discharges, were considered the leading cause of these outbreaks. The presence of various pollutants as well as certain weather conditions may contribute synergistically to the onset of exacerbations in patients with a previous diagnosis of asthma. This study aims to investigate whether atmospheric electrical discharges exert any influence on the number of emergency admissions due to childhood asthma, in autumn, in Lisbon. The investigation will examine whether there are isolated or combined effects of meteorological variables, pollutant and pollen concentrations that favour an increase in the number of exacerbations of asthma symptoms. For this purpose we compared the number of asthma admissions in periods with and without thunderstorms in a Lisbon paediatric emergency service. Increasing pollen concentrations attributed to thunderstorms reported in the literature were not found in Lisbon in the days analysed. There was also an absence of relationship between admissions for asthma and air pollution. Associations between hospitalisations due to asthma crisis and atmospheric variables were documented. In Lisbon, no influence of atmospheric electrical discharges in the variation of the number of emergency admissions due to childhood asthma was verified in the studied period (autumn). On the contrary, it was verified that a decrease in minimum temperature positively reinforces these admissions.