The impact of airborne dust on respiratory health in children living in the Aral Sea region

Background Anecdotally, people living in the Aral Sea region report an increase in the prevalence of respiratory illnesses, particularly in children, and there is widespread belief that this is due to dust from the Aral Sea bed. Methods We conducted a survey of respiratory symptoms and lung function in children aged 710 years living in 18 communities in 6 geographical regions in the Aral Sea area. We monitored dust deposition rates monthly for the duration of the study. Results The overall prevalence of recent wheeze was low at 4.2, but this figure varied with region and was higher in the more accessible urban and delta regions and lower in the more remote regions. We found no evidence of an association between local annual dust deposition and specific respiratory symptoms. Lung function results also showed variation between geographical regions not explained by annual dust deposition. After allowing for region of residence, however, there was some evidence of an inverse association between percentage predicted forced expiratory volume in 1 s(FEV1) and dust exposure during the summer months (change in percentage predicted FEV1 per 1000 kg/ha annual dust deposition 1.465) (95 confidence interval 2.519 to 0.412); however, in winter, the reverse was true. Conclusions The prevalence of asthma is low in the Aral Sea area and appears to be unrelated to dust exposure. Exposure to dust did not explain the main variations in lung function between geographical regions but high levels of dust exposure during the summer may have an adverse effect on lung function.