To identify temporal relationships between changes in air pollution and health, a case control respiratory related health study was carried out among 12-16 year old students at schools situated in and around the Kandy city, and its relation to traffic related air pollution was investigated into in this study. Two study populations of about 380 students each were selected. One study population is from the city schools situated by the roads with high traffic intensity, and the other from village schools situated by the roads with insignificant traffic intensity. Average traffic intensity by the city schools was 21 vehicles/min and it was less than 1 vehicle/min by the village schools. Average PM10 count taken as the measure of the air quality was 121 ug/m3 in the city and 84 ug/m3 in the village.
Data were collected using answers given to a questionnaire by students and analysis of the results show that there is a considerable difference in health pattern between children attending city schools and village schools. Some confounding factors such as exposure to black smoke at home environment, cigarette smoke, mosquito-coil smoke and firewood smoke and the family’s socio-economic status were also covered in the questionnaire. None of these factors, however, is found to have any significant influence on the difference in health pattern.
It is therefore highly probable that the traffic related air pollution has caused the observed difference in the respiratory related health of the students attending schools in the Kandy city and outside the Kandy city where the traffic intensity insignificant.