Epidemiological investigation has shown that organic contamination of the Songhua River is a risk
factor for tumor development among residents who live nearby. A mutagenesis is induced by organic
contamination using short-term genotoxic bio-assays. To further investigate the risk of carcinogenic
potential to human health, the NIH3T3 cell line was used to examine the induction of transformation by
diethyl ether extracts of water samples taken from the Songhua River in the summer of 1994 and the
winter of 1995. The results indicated that the malignant transformed foci were induced by diethyl ether
extracts. Cellular transformation frequencies showed a dose response. Malignant cells possessed
typical characteristics in cell growth and in the cellular anchorage dependent test while the control cells
did not. Thus, this study demonstrates diethyl ether extracts of water samples could induce cell
transformation of NIH3T3 cells. Evidence was provided the possible relationship between organic
pollution and carcinogenic potential.
Key words: Diethyl ether extracts, NIH3T3 cells, cell transformation, malignant cells, the Songhua River.