Polychlorinated biphenyls, organochlorine pesticides and chlorobenzenes content of livers from Atlantic cod (Gadus morhua) caught off Halifax Nova Scotia.

The mean levels ± s.d., (ranges) of organochlorines, pesticides, chlorobenzenes and polychlorinated biphenyl were determined in the livers of 100 Atlantic cod (Gadus morhua) caught off the east coast of Canada in 1980 and were as follows: PCB 1.71±0.90 (0.24-4.33); p,p'-DDE 0.28±0.15 (0.01-0.84); p,p'-DDD 0.10±0.09 (trace-0.84); p,p'-DDT 0.15±0.09 (ND-0.58); α-HCH 0.06±0.02 (trace-0.10); α-HCH (ND-trace); heptachlor 0.02±0.01 (ND-0.04); heptachlor epoxide 0.15±0.37 (ND-2.16); dieldrin 0.06±0.11 (ND-0.71); hexachlorobenzene 0.02±0.01 (trace-0.05) mg kg(-1) (wet wt.). The levels of these compounds in 1980 have not changed over the previous eight years with the exception of PCB and the DDT group where there appears to be a general decline between 1972 and 1975 with no significant change thereafter.