[Trace elements and endemic goiter]

The effects of xenobiotics on morphological structure and function of the thyroid gland (TG) were analysed. Salts of heavy metals (zink, lead, copper, cadmium, surma etc.) were measured in TG of 152 citizens of Kama region who had died of trauma in the 1960s (n = 73), 1990s (n = 20) and 2000s (n = 52). TG is shown to accumulate xenobiotics. As the examinees had no occupational contact with heavy metal salts (HMS), their deposits in TG is explained by anthropogenic pollution of the environment. HMS in the thyroid tissue was much lower than in later decades indicating aggravation of environmental pollution in the Urals. Being protoplasmic poisons, HMS bind proteins and provoke immune reaction. All the examinees who died after 2000 had histologically proved deposits of immunocompetent cells in TG tissue--lymphoid and plasmic TG infiltration. In the 1960s these TG alterations were absent. Goiter endemia can be stopped by improvement of environmental protection in each ecopolluted region and mass iodine prophylaxis.