The Michigan polybrominated-biphenyl (59536651) (PBB) incident was presented to illustrate community health problems relating to contamination from industrial chemicals. The incident referred to the accidental incorporation of PBB from the Michigan Chemical Company into feed for dairy cattle occurring in 1973. The accidental mixup of PBB and the magnesium-oxide intended for the feed was not discovered for approximately 1 year, resulting in considerable contamination of food products. PBB was determined in beef, milk and milk products, and in swine, sheep, chickens and eggs. The effects of PBB on cows included refusal of feed, decreased milk production, anorexia, shrinking of the udders, reproductive problems, lameness, swollen joints, abnormal hoof growth, and hyperkeratosis. Experimental studies showed comparable effects from feeding cattle 25 grams PBB per day for a period of 60 days. Studies of 110 individuals on farms where cattle were quarantined because of high PBB levels indicated that approximately 44 percent of the adults and 71 percent of the children had PBB blood levels greater than or equal to 0.02 parts per million, relative to 1.4 percent of the adults and 3.3 percent of the children on nonquarantined farms. Fat biopsies indicated adipose levels of PBB as much as 300 times greater than blood levels. No disease or symptom complex was consistently related to the exposed individuals although complaints of headaches, fatigue, balance problems, rashes, and increased anxiety were reported.
Occupational Safety and Health Symposia, 1977, Division of Technical Services, NIOSH, U.S. Department of Health, Education and Welfare, Cincinnati, Ohio, DHEW (NIOSH) Publication No. 78-169