[Environmental factors and asthma in the child population of Vizcaya].

Authors have studied relationship of several environmental factors (climatic changes and atmospheric pollution) and occurrence of asthma in childhood population of Vizcaya. Sample studied was composed of 290 asthmatic children and the same normal controls as counterpart exposed to equal risk. They also consider data obtained of the children's Hospital of Cruces emergency room. Follow-up was for one year. They do not find any relationship between acute asthma and levels of several air contaminants (SO2, OxN, fumes) neither with wind's direction and velocity and ambient humidity. A significant relation was found between autumn epidemic days and increase in environmental temperature. No relation of asthma and viral epidemiology or respiratory infections was found. The fact that "asthma epidemics" in Vizcaya happen yearly at the end of summer and that children affected are atopic, make authors think that the determinant factors are several: September is for many children the end of summer holidays, changing their habitat and climatic conditions.