Levels of specific polychlorinated biphenyl congeners in fatty foods from five Canadian cities between 1986 and 1988.

A total of 155 fatty food composites from five major Canadian cities were analysed for 36 selected polychlorinated biphenyl (PCB) congeners. Total PCB congener levels of more than 1 ng/g (wet weight) were found in fresh water fish, canned fish, butter, marine fish and cheese, with fresh water fish (18.7 ng/g) containing 5 to 10 times more total PCBs than the other four food commodities. Milk (2%), cooking oils/salads and canned meat soup contained less than 0.1 ng/g (wet weight). The observed total PCB residue levels in fatty foods were well within the Canadian guidelines for fish, dairy products, poultry, eggs and beef. The most predominant congeners found in fish, butter, cheese, meat and poultry were the 2,2',4,4',5-, 2,3',4,4', 5-pentachloro-, 2,2',3,4,4',5'-, 2,2',4,4',5,5'-hexachloro- and 2,2',3,4,4',5,5'-heptachlorobiphenyls. The predominant congener pattern was not always evident in other dairy products (e.g. ice cream) and processed foods (e.g. canned meat soup). An attempt was made to relate the intake of PCB congeners from fatty foods with congener levels found in adipose tissue of Canadians. The estimated daily intake of some specific PCB congeners from fatty foods, in most cases accounted for more than half the total deposit of these congeners in adipose tissue of Canadians.