Mutagens in a river heavily polluted with paper recycling wastes: results of field and laboratory mutagen assays.
Paper recycling industries generate considerable quantities of waterborne wastes, and thus water pollution constitutes the greatest environmental problem associated with this industrial activity [Hunt and Franklin, 1973]. Generally the impact of this water pollution is considered in terms of aesthetic blight and deterioration of water quality. We present data that document another aspect of this pollution, the environmental contamination of an aquatic ecosystem with mutagenic materials. A natural population of the fern Osmunda regalis growing in a river heavily polluted with paper recycling wastes had a high incidence of chromosome mutations. This population was monitored for four years for the frequency of two-break chromosome mutations. These mutations were postzygotic in origin and suggested the presence of mutagens in the river water. The fern population is downstream from the outfalls of a paper recycling mill, which was discharging 13.3 X 10(6) liters of untreated paper recycling waste per day. In 1977 a waste-water-treatment facility was constructed to remove the solid waste previously discharged into the river. This facility generates 69,300 kg of solid waste daily, which is taken to a landfill. Periodic samples of this solid waste were collected from the waste-treatment facility in the summer of 1978, extracted with various solvents, and the extracts tested for mutagenic activity with the Salmonella/mammalian microsome mutagenicity test [Ames et al, 1975]. A majority of the solid waste samples contained mutagenic materials, but in all cases S-9 activation was required for mutagenic activity. The samples also were assayed with the soybean mitotic crossing-over assay [Vig, 1975]. Four out of six samples were positive. These results document the presence of mutagens in the solid waste generated by a paper recycling industry and the genetic impact of these mutagens on the local biota.