Genetic activity in Saccharomyces cerevisiae of compounds found in effluents of pulp and paper mills.

20 compounds identified in pulp mill effluents were screened for genetic activity in growing cells using Saccharomyces cerevisiae strains D7 and XV185-14C without and with S9. Nine compounds were positive in one or the other yeast strain (7 in D7; 2 in XV185-14C). One additional compound showed weak effects and two others showed elevated frequencies/survivor without absolute increases of mutants. The presence of S9 enabled detection of one positive and two weak effects, it enhanced the genetic activity of one compound in each strain, and it reduced the mutagenic effects of 4 others in strain D7. 7 of the 20 chemicals tested have been shown previously to be mutagenic in the Salmonella/mammalian-microsome assay. Of the 7 bacterial mutagens, 6 were positive and 1 had a weak effect in yeast.