Effect of air pollution on respiratory symptoms of junior high school students in Indonesia

In 1994, 16,187 junior high school students were surveyed in Jakarta and surrounding cities, Indonesia, to study the effect of air pollution on respiratory illnesses. Nitrogen dioxide (NO2) was measured by the filter badge developed by Yanagisawa and Nishimura as a measure of air pollution. The average concentration of NO2 is the highest in central Jakarta and Tangerang (22-30 ppb), the lowest in rural areas (5-11 ppb), and in other cities, 11-20 ppb. Self-administered questionnaires were given to the students in 29 schools to obtain respiratory symptoms of cough, phlegm and wheeze. A significant relationship was found in this study between NO2 exposure levels and prevalence rates of cough, phlegm, and wheezing without cold, which were 27.7 to 38.7%, 15.0 to 21.9%, and 1.4 to 2.9%, respectively. Prevalence rates of persistent cough and persistent phlegm were 7.3 to 10.8% and 4.5 to 5.0% respectively. These rates were higher than those found by other researchers. This difference may be partly due to the survey methods. The more polluted, the higher the prevalence rate of respiratory symptoms.