Mutagenicity and transformation by recycled water.

Increased use of contaminated water and long-range plans for the direct use of recycled water necessitate a careful assessment of the potential health effect on the population. Selected in vitro assays were used to evaluate the mutagenic and carcinogenic potential of a concentrated, recycled water sample. It was found that the concentrated water induced mutagenicity in hamster lung cells and cellular transformation in human embryonic lung fibroblasts. The use of in vitro analyses in conjunction with epidemiologic studies in determining the human risks of environmental carcinogens is discussed.