Quantification of CVesium-137 Infernal Equivalent Dose in a Cohort of Children from Narodichi, Ukraine Utilizing a Mechanistic Ecological Model

摘要

Impoverished children living in Narodichi, Ukraine have been chronically exposed to low-doses of cesium-137 derived from the Chernobyl Nuclear Power Plant accident in 1986. Narodichi's children represent an important cohort for determining the presence or absence of deterministic health effects from chronic internal low-dose beta and gamma radiation. Epidemiological studies have already discovered associations between internal cesium-137 annual dose in children and adverse immunological and pulmonary consequences. However, more adequate dose data, in conjunction with epidemiological and toxicological study, are needed to further determine causality. We conducted a multivariate linear regression of whole body dose estimations (utilizing whole body count (WBC) method) and associated risk factors for the Narodichi cohort. The predictive model identified proximal residential soil activity as the most significant predictor of dose (t=4.92, p＜0.001). Based on this finding and the fact that citizens of Narodichi use residential soil for subsistence agriculture, we utilized a validated agricultural-soil based mechanistic model to further estimate dose for the cohort. The geometric mean whole body dose from the mechanistic model was 0.112 mSv/y, which was significantly lower than the geometric mean dose estimated by the WBC method (t=-57.57, p＜0.001). However, both dose estimation models were significantly correlated (r=0.416, p＜0.001). The mechanistic model does not include the consumption of highly contaminated non-agricultural food products and could explain the significantly lower dose estimates when compared to the WBC method.