DNA damage and repair in white blood cells at occupational exposure

Abstract

:The present work was aimed at finding appropriate biomarkers applicable in molecular epidemiological surveys of occupationally exposed individuals and/or population in order to prove low dose effects. Blood samples were taken from NPP workers, in the ‘strict regimen’ area (exposed group) and from the administration staff (control group). The spontaneous and induced (exposed to a challenge dose of 2,0 Gy gamma irradiation) DNA repair synthesis in leucocytes, the level of DNA damage by single cell gel-electrophoresis in lymphocytes and the concentration of malonedialdehyde in blood serum, were analyzed. A significant decrease of potentially lethal damage in leucocytes as well as reduction of DNA double strand breaks level in lymphocytes of persons with ‘mean annual dose’ lower or equal to 5 mSv/a was found, compared to the control group. A higher repair capacity corresponding to elevated protein synthesis after a challenging dose of 2,0 Gy gamma rays and a significant decrease in the level of oxidative stress in the blood plasma were established in persons from the same group. The present investigation showed that annual doses not higher than twice the natural radiation background exert positive effects on DNA damage and repair, increase cellular resistance and decrease oxidative stress.