Organochlorine pesticides and polychlorinated biphenyls in cod from the southern Baltic, 1981.

98 samples of muscle tissue of cod ranging form 51 to 60 cm in total length and netted in 1981 in the southern part of the Baltic Sea were analysed for polychlorinated biphenyls (PCBs), DDT and its metabolites (DDE and DDD), hexachlorobenzene (HCB), and isomers of benzenehexachloride (alpha-, beta-, gamma- and delta-BHC). Mean values obtained related to wet weight for cod muscle tissue were: 0.77 micrograms kg/HCB, 0.71 micrograms kg/alpha-BHC, 3.8 micrograms kg/gamma-BHC, 5.2 micrograms kg/p,p'-DDe, 2.6 micrograms kg/p,p'-DDD, 2.6 micrograms kg/p,p'-DDT, 10 micrograms kg/sigma DDT and 180 micrograms kg/PCB; beta-BHC was detectable in trace amounts and delta-BHC was undetected. Generally residue levels of organochlorine pesticides and PCBs found in the muscles were low, and substantial decrease of sigma DDT and less of PCB levels in recent years when compared with data noted in 1969-1970 and 1972-1974 is noticeable.