Investigations of chlorinated thiophenes: a group of bioaccumulable compounds identified in the effluents from kraft bleaching

Several chlorinated thiophenes were identified in spent kraft bleach liquors by comparison with synthesized standard compounds. The synthesized compounds were isomers of the thiophenes in the wastewaters, and had octanol/water partition coefficients in the range 3.8-5.6. These compounds were accumulated by bleak (Alburnus alburnus), and about one-third of the total accumulated remained in the fish after an elimination period of 14 days. These compounds were also moderately toxic towards the crustacean, Nitocra spinipes, and three compounds showed mutagenic activity in the Ames bioassay. It was suggested that chlorinated thiophenes could be used as tracers to investigate the distribution of pulp mill wastewaters in the environment.