Environmental chemicals have been found in human milk since the 1950s, and periodically there are reports of polychlorinated biphenyls (PCBs) in breast milk. Polychlorinated biphenyls are stored in body fat and are not readily excreted except in the fat of breast milk. PCB manufacture ceased in the US in the 1970s.
The routes of PCB exposure for the general population are not known in detail, but low-level contamination of food is a likely source. Persons who consume fish from contaminated waters, such as the Hudson River and Lake Michigan, may have greater exposure to PCBs. Opportunity still exists for skin to come in contact with and absorb PCBs from old electrical or laboratory equipment.
Studies in the US
In the US there are no known clinical effects of exposure to PCBs through breast milk. Two cohorts of US children—one in Michigan with about 250 children and the other in North Carolina with about 750 children—whose development was followed from birth had their exposure to PCBs measured. In the North Carolina study, prenatal exposure to PCBs but not exposure through breast milk was associated with poorer performance on the Psychomotor Index from the Bayley Scales of Infant Development from 6 months through 24 months of age.1,2 In the Michigan study, poorer visual recognition memory performance in 7-month-old infants was associated with cord serum PCB level and maternal contaminated fish consumption.3 There was no relation with breast milk exposure.
Studies in Asia
"Yusho" and "yucheng" both mean oil disease in Japanese and Chinese, respectively.
- Copyright © 1994 by the American Academy of Pediatrics