Changing prevalence of asthma among schoolchildren in Israel.

This survey was part of a health monitoring system operated in the vicinity of a new power plant in Israel. The aim of this analysis was to determine whether a temporal trend of increased prevalence of asthma can be observed among cohorts of same-aged children, between 1980 and 1989. Schoolchildren were followed up between 1980 and 1989. They performed pulmonary function tests (PFTs), and their parents filled out American Thoracic Society-National Heart and Lung Institute (ATS-NHLI) health questionnaires. This report deals with the changes in the prevalence of asthma, related respiratory conditions and PFT in four cross-sectional data sets gathered among eighth-grade schoolchildren (aged 13-14 yrs). A highly significant (p=0.0005) increase in the prevalence of asthma (from 5.6% in 1980 to 11.2% in 1989), and of wheezing accompanied by shortness of breath (p=0.0009) could be observed. A similar trend could not be found for the prevalence of bronchitis among these children. PFTs of children suffering from asthma or from wheeze accompanied by shortness of breath were lower than those of healthy children. Changes in prevalence of background variables over time could not explain these findings. The significant rise in the prevalence of asthma coupled with reduced pulmonary function test results among asthmatic children, seems to reflect a true increase in morbidity. Temporal changes in the prevalence of background variables as well as proximity to the power plant could not explain this trend.