The effect of background variables on human peripheral lymphocyte micronuclei.

Application of biological methods for assessment of occupational and environmental exposure to single agents or complex mixtures is optimized by determination of the possible influence of background factors on the biological endpoint of interest. Analysis of micronuclei in peripheral blood lymphocytes using the cytokinesis-block method was performed on healthy volunteers up to three times for each individual at intervals of approximately four months. Questionnaires were administered to ascertain recent health history and lifestyle factors such as smoking and drinking habits. Results to date indicate that age (r = 0.45, p = 0.001) and estimated number of diagnostic X-rays during the past year (r = 0.35, p = 0.01) contribute significantly to increased frequency of micronuclei. Information on the potential influence of background factors is critical for appropriate statistical analysis of data from occupational and population monitoring studies that utilize the cytokinesis block lymphocyte micronucleus assay to assess exposure to genotoxic agents.