A fraction of beech wood mutagenic in the Salmonella/mammalian microsome assay.

Base-pair substitution mutagens were isolated from the dusts of several untreated samples of beech wood and tested for mutagenicity in the Salmonella/mammalian microsome assay. These compounds reverted Salmonella typhimurium his- TA 100 in the presence of Aroclor-induced rat S9. These mutagens were found to be toxic to the cells when tested in a histidine-rich medium (complete medium). Mutagenicity of the non-fractionated wood-dust extracts due to the presence of some inhibitory compounds of wood could not be confirmed significantly. These inhibitors counteracted the reversion of bacteria when the known mutagens, such as benzo(a)pyrene, aflatoxin B1 and ethyl methanesulfonate, were tested. The results indicate that beech wood-dust contains mutagenic constituent(s) which may contribute to their assumed tumor bearing effects among wood-workers.