The incidence of unstable chromosome aberrations in peripheral blood lymphocytes from unirradiated and occupationally exposed people.

Peripheral blood lymphocytes from unirradiated control subjects and workers exposed within permitted limits to gamma-radiation, have been examined for the incidence of dicentric and acentric chromosome aberrations. The results are compared with a review of data published elsewhere. Background levels show inter-laboratory variation and possible reasons for this are discussed. By combining the present data with those from the literature the spontaneous incidence of dicentric aberrations in approx. 0.55 X 10(-3) and for acentrics is 3.7 X 10(-3). In occupationally exposed subjects a significantly higher incidence of aberrations was found. When allowance was made for the turnover of lymphocytes for the period over which each man had worked with radiation a linear dose--effect relationship was apparent. The incidence of dicentrics was 2.22 +/- 0.94 X 10(-4) rad-1 and for all unstable aberrations 8.24 +/- 2.8 X 10(-4) rad-1. These are in reasonable agreement with dose--response data obtained in vitro.