NO INCREASED DNA-DAMAGE IN PERIPHERAL LYMPHOCYTES OF SEWAGE WORKERS AS EVALUATED BY ALKALINE SINGLE-CELL GEL-ELECTROPHORESIS

Objectives-To study whether sewage workers are exposed to genotoxic su bstances. An increased risk of cancers among sewage workers has been n oted. If this increased risk is due to an exposure to genotoxic agents , primary DNA damage could be used as a biological marker of exposure. Methods-In a cross sectional study, DNA damage in peripheral lymphocy tes from 35 sewage workers and 30 controls was compared with alkaline single cell gel electrophoresis, a technique for detecting single stra nd breaks and alkali labile sites in DNA. The controls were selected f rom among municipal workers matched for age and smoking habit. Informa tion about occupational exposures and possible confounders was collect ed by means of a questionnaire. Results-No increase in DNA damage was found among the sewage workers when compared with the unexposed contro ls. Conclusion-The failure to detect increased damage to DNA in periph eral lymphocytes by alkaline single cell gel electrophoresis suggests that the sewage workers studied here were not exposed to genotoxic age nts to a greater extent than other municipal workers, It may be, howev er, that the lymphocyte is not the appropriate target cell to study, o r that sewage workers are exposed to carcinogens which do not damage t he genetic material.