Environmental conditions and childhood asthma in Lisbon. An exploratory analysis for autumn thunderstorm

Resumo

Asthma attacks triggered by thunderstorms have been described inseveralcountries. The rises in pollen concentrations, attributed to atmospheric electricaldischarges, were considered the leading cause of these outbreaks. The presence of variouspollutants as well as certain weather conditions may contribute synergistically to theonsetof exacerbations in patients with a previous diagnosis of asthma. This study aims toinvestigate whether atmospheric electrical discharges exert any influence on the numberof emergency admissions due to childhood asthma, in autumn, in Lisbon. The investigationwill examine whether there are isolated or combined effects of meteorological variables,pollutantand pollen concentrations that favour an increase in the number of exacerbationsof asthma symptoms. For this purpose we compared the number of asthmaadmissions in periodswith and without thunderstorms in a Lisbon paediatric emergencyservice. Increasingpollen concentrations attributed to thunderstorms reported in the literaturewere not found in Lisbon in the days analysed. There was also an absence of relationshipbetween admissions for asthma and air pollution. Associations between hospitalisationsdue to asthmacrisis and atmospheric variables were documented. In Lisbon, no influence of atmosphericelectrical discharges in the variation of the number of emergencyadmissions due to childhood asthma was verified in the studied period (autumn).On the contrary, it was verified that a decrease in minimum temperature positively reinforcesthese admissions.