DOUGLAS-FIR - A 3RD WOOD-DRYING CONDENSATE FOUND TO EXHIBIT IN-VITRO CYTOTOXICITY AND GENOTOXICITY

The present study applies the approach described in Mark et al.(1) for the testing of toxic chemicals produced during the drying of Douglas- fir. The genotoxic potential of Douglas-fir condensate has been previo usly unexplored and is thus an area of appropriate concern to the fore st products industry, regulatory agencies, and the general public. Pre vious research conducted in this laboratory has identified two wood-dr ying condensates that yield positive cytotoxic and genotoxic effects. The results of testing Southern yellow pine and Eastern white pine con densates have been reported elsewhere. Douglas-fir condensate, a third wood-drying condensate, was added in vitro in concentrations ranging from 0.1 to 100 mu l/ml to cultures of Chinese Hamster Ovary (CHO-WBL) cells. A dose response curve was observed with this condensate for bo th cytotoxicity and genotoxicity. The number of viable cells as well a s the mitotic index (MI) and proliferative rate index (PRI) varied inv ersely with dosage. The result of chromosome aberration (Abs) analysis and sister chromatid exchange (SCE) analysis, both cytogenetic measur es of genotoxicity, also gave statistically significant results.