137Cesium Exposure and Spirometry Measures in Ukrainian Children Affected by the Chernobyl Nuclear Incident

BACKGROUND After the Chernobyl accident in 1986, children of the contaminated Narodichesky region of Ukraine were obliged to participate in a yearly medical screening. They have been exposed to 137cesium (137Cs; half-life = 30 years) in contaminated soils, air, and food. OBJECTIVE Using a "natural experiment" approach and a longitudinal prospective cohort study design, we investigated the association of soil 137Cs and spirometry measures for 415 children using 1,888 repeated measurements from 1993 to 1998. METHODS Mean baseline village soil 137Cs measurements, which varied from 29.0 to 879 kBq/m2, were used as exposure indicators. A standardized spirometry protocol and prediction equations specific to Ukrainian children were used by the same pulmonologist in all screenings. RESULTS Children living in villages with the highest quintile of soil 137Cs were 2.60 times more likely to have forced vital capacity (FVC) < 80% of predicted [95% confidence interval (CI), 1.07-6.34] and 5.08 times more likely to have a ratio of forced expiratory volume in 1 sec (FEV1) to FVC% < 80% (95% CI, 1.02-25.19). We found statistically significant evidence of both airway obstruction (FEV1/FVC%, peak expiratory flow, and maximum expiratory flow at 25%, 50%, and 75% of FVC) and restriction (FVC) with increasing soil 137Cs. CONCLUSIONS These findings are unique and suggest significant airway obstruction and restriction consequences for children chronically exposed to low-dose radioactive contaminants such as those found downwind of the Chernobyl Nuclear Power Plant.