RECEIVING WATER ENVIRONMENTAL-EFFECTS ASSOCIATED WITH DISCHARGES FROMONTARIO PULP-MILLS

White sucker collected near chlorinated bleached kraft mills exhibited the highest induction of liver detoxification enzymes (measured as et hoxyresorufin-o-deethylase activity EROD) and the highest measured lev els of chlorinated dioxins and furans. However, elevated enzyme activi ty was observed in fish from sites which did not use chlorine. Further more, decreased circulating levels of sex steroids, decreased gonadal size and increased liver size were observed in fish collected at sites with and without chlorine bleaching and at sites with secondary treat ment of effluent.