Application of Geoinformation Technologies for minimization of thyroid gland diseases in the impact areas of the radioiodine fallout

Modern geoinformation technologies are widely used in spatial data analysis including medical geography locating spatial distribution of site-specific diseases. Following obviously essential problems the major part of such maps have been constructed for the most dangerous diseases. Although thyroid goiter has been known since ancient times, but it was not earlier than the middle of XIXth century when Chatain has related this disease to deficiency of the particular chemical element (iodine). And not earlier than 1938 Vinogradov has coined the notion of biogeochemical provinces to distinguish areas of specific endemic disease of geochemical origin and summarized natural factors causing iodine deficiency in local diets and contributing to goiter manifestation. The Chernobyl accident has highlighted the problem of a combined negative impact of radioiodine contamination and stable iodine deficiency. Technogenic and natural isotopes of iodine have specific spatial structure and this fact opened new prospects in identification of areas under different risk levels by using GIS technology. To study the geochemical factors responsible for distribution of the thyroid gland diseases in Chernobyl fallout area we have created and develop a specialized geographic information system basing on the idea of a two-layers spatial structure of modern noosphere (Korobova, 2017) according to which the natural geochemical background reflected in the soil cover structure is overlain by technogenic contamination fields. As a result an interferential imagery is produced. This image can be interpreted as a risk map which in turn may be verified by health effects. The study was performed for 4 regions subjected to the Chernobyl accident (Bryansk, Oryol, Kaluga and Tula oblast’s). An overlay of natural iodine deficiency and technogenic iodine fallout map layers classified by 6 zones from minimum to maximum risk allowed to identify 12 zones and to evaluate a combined risk for 93 rural districts. Comparison of the created combined risk map and radionuclide contamination map with regional medical data on standardized incidence of thyroid cancer (code C-73 ICD-10) had a higher correlation (r = 0.493, n = 93) compared to the map of the levels of radionuclide loss. All this, obviously, demonstrates that the proposed GIS technology will be useful to adequately minimize in any case thyroid diseases.

References
Korobova, E.M. Principles of spatial organization and evolution of the biosphere and the noosphere. Geochem. Int. 55, 1205–1282 (2017) doi:10.1134/S001670291713002X