RESUMO
Clinical and epidemiologic study of chronic somatic discases in workers engaged into thorium production (main group) in short-term period revealed significantly higher prevalence of vegetative neurosis, asthenic state, chronic gastritis, arterial hypotension, chronic nasopharyngitis and higher risk of those conditions, if compared to reference group over the period since 1947 to 1959. These findings are caused by combined exposure to occupational hazards: outer and inner radiation due to long-lived thorium, thoron and their radioactive products, associated exposure to toxic chemicals. Chronic radiation sickness was diagnosed only in individuals who worked over the period since 1947 to 1959 and demonstrated hemopoietic disorders associated with functional neural system impairment. Better sanitary and hygienic work conditions and more efficient individual protective means ("Lepestok" respirator) resulted in reliably decreased risk of chronic somatic diseases among thorium production workers employed since 1960 to 1972.