DNA - PROTEIN CROSS-LINKS, A BIOMARKER OF EXPOSURE TO FORMALDEHYDE - IN-VITRO AND IN-VIVO STUDIES

Formaldehyde (FA) is a widely produced industrial chemical. Sufficient evidence exists to consider FA as an animal carcinogen, In humans the evidence is not conclusive. DNA-protein crosslinks (DPC) may be one o f the early lesions in the carcinogenesis process in cells following e xposures to carcinogens, It has been shown in in vitro tests that FA c an form DPC. We examined the amount of DPC formation in human white bl ood cells exposed to FA in vitro and in white blood cells taken from 1 2 workers exposed to FA and eight controls, We found a significant dif ference (P = 0.03) in the amount of DPC among exposed (mean +/- SD 28 +/- 5%, minimum 21%, maximum 38%) than among the unexposed controls (m ean +/- SD 22 +/- 6%, minimum 16%, maximum 32%), Of the 12 exposed wor kers, four (33%) showed crosslink values above the upper range of cont rols, We also found a linear relationship between years of exposure an d the amount of DPC, We conclude that our data indicate a possible mec hanism of FA carcinogenicity in humans and that DPC can be used as a m ethod for biological monitoring of exposure to FA.