Dietary supplementation with radionuclide free food improves children's health following community exposure to 137Cesium: a prospective study

Background Following the Chernobyl nuclear disaster of 1986, vast areas of Ukraine became contaminated with radionuclides. We examined health effects of school-based food intervention for children in a rural region Narodichi, Ukraine, exposed to low-level radiation through diet of locally produced foods. Until 1995, children received three daily meals with low content of artificial radionuclides which were subsequently reduced to two. Methods Annual health screening data (1993-1998) were examined using a quasi-experimental regression discontinuity analysis (n = 947 children; 3,573 repeated measurements). Generalized Estimating Equation models evaluated effect of the food supplementation reduction on hematologic measures and prevalence of anemia, acute respiratory illnesses and diseases of immune system. Results Prior improvement of several hematologic parameters diminished after food supplementation was reduced. From 1995 to 1996, levels of hemoglobin and erythrocytes decreased from 12.63 (95 % CI: 12.56-12.71) to 12.46 g/dL (% CI: 12.39-12.52) and from 4.10 (95 % CI: 4.07-4.12) to 4.02 (95 % CI: 4.00-4.04) x 10.sup.12/L, respectively. In agreement, the prevalence ratio (PR) of previously declining anemia increased from 0.57 to 1.31 per year (p.sub.interaction < .0001). The relation between food supplementation and hemoglobin levels was modified by residential .sup.137Cs soil levels. After food supply reduction, PR of common cold and bronchitis increased from 1.27 to 2.32 per year (p.sub.interaction = 0.01) and from 1.09 to 1.24 per year (p.sub.interaction = 0.43), respectively. Conclusions Food supplementation provided by the Ukrainian government likely prevented development of anemia in many of the children residing in the contaminated district. Food supplementation after the community exposure to radioactivity through a diet of locally grown foods should be considered as an effective approach to reduce adverse health effects of radiation. Keywords: Ionizing radiation, Chernobyl, Blood indices, Regression discontinuity