Prevalence of asthma and other respiratory symptoms in children living near and away from opencast coal mining sites.

BACKGROUND: Public concern about respiratory conditions prompted the investigation of asthma and other respiratory diseases in children living near and away from opencast coal mining sites. METHODS: We selected all 4860 children aged 1--11 years from five socioeconomically matched pairs of communities close to (OC) and away from (CC) active opencast sites. A postal questionnaire collected data on health and lifestyle. Outcomes were the cumulative and period prevalence (2 and 12 months) of wheeze, asthma, bronchitis and other respiratory symptoms. RESULTS: The cumulative prevalence of wheeze varied from 30% to 40% across the ten communities, it was 36% in OC and 37% in CC. The cumulative prevalence of asthma was 22% in both OC and CC, varying between 12% and 24%. We found little evidence for associations between living near an opencast site and an increased prevalence of respiratory illnesses, or asthma severity. Some outcomes such as allergies, hayfever, or cough varied little across the study communities. Others, such as the use of asthma medication, the number of severe wheezing attacks in the past year or tonsillitis showed large variation. These similarities and variations were not explained by differences in lifestyle factors or differences in health services delivery and remain unexplained. CONCLUSIONS: There was little evidence of an association between residential proximity to opencast mining sites and cumulative or period prevalence of respiratory illness, or asthma severity. Some variations in health outcomes between communities remained unexplained.