Comparative studies on cytotoxicity of micropollutants in water: Principle of cytotoxicity matrix

Cytotoxicities were investigated with chemicals including pesticides, industrial materials, and chlorination by-products using colony formation inhibition of L-929 cells and membrane damage of “liposomes” to develop the simple bioassays for estimation of human hazardous micropollutants in water. Some chemicals including pesticides and chlorination by-products strongly inhibited colony formation of L-929 cells, and the inhibition was dose dependent. But most cytotoxic substances did not increase membrane permeability of liposomes, suggesting that Cytotoxicity of these chemicals does not arise from direct damage of cell membranes. The IC10 and IC50,10 and 50% inhibition concentrations, were obtained from the dose-response curve of colony formation. The IC10 showed good correlation (r = 0.75) to LD50 of rat by intraperitoneal administration but not to those by oral administration. The results were compared to those with viability of HL-60 cells, phagocytic activity of mice peritoneal macrophages, glycogenolysis, and LDH release of rat liver hepatocytes. The susceptibilities were largely different among these Cytotoxicity tests, and the colony formation inhibition test gave similar results to the viability of HL-60 cells. The principle of “cytotcxicity matrix” was developed from the comparison of cytotoxicities for each chemical. The characteristic relation was found between the chemical structure and the pattern of the Cytotoxicity matrix, indicating that the Cytotoxicity matrix may be useful for predicting the origin and nature of micropollutants. © 1994 by John Wiley & Sons, Inc..