Lessons from the polybrominated diphenyl ethers (PBDEs): precautionary principle, primary prevention, and the value of community-based body-burden monitoring using breast milk.
Levels of chemicals in humans (body burdens) are useful indicators of environmental quality and of community health. Chemical body burdens are easily monitored using breast milk samples collected from first-time mothers (primiparae) with infants 2-8 weeks of age. Currently, there is no body-burden monitoring program using breast milk in the United States, although ad hoc systems operate successfully in several European countries. In this article we describe the value of such monitoring and important considerations of how it might be accomplished, drawing from our experiences with pilot monitoring projects. Breast milk has several advantages as a sampling matrix: It is simple and noninvasive, with samples collected by the mother. It monitors body burdens in reproductive-age women and it estimates in utero and nursing-infant exposures, all important to community health. Time-trend data from breast milk monitoring serve as a warning system that identifies chemicals whose body burdens and human exposures are increasing. Time trends also serve as a report card on how well past regulatory actions have reduced environmental chemical exposures. Body-burden monitoring using breast milk should include educational programs that encourage breast-feeding. Finally, and most important, clean breast milk matters to people and leads to primary prevention--the limiting of chemical exposures. We illustrate these advantages with polybrominated diphenyl ethers (PBDEs), a formerly obscure group of brominated flame retardants that rose to prominence and were regulated in Sweden when residue levels were found to be rapidly increasing in breast milk. A community-based body-burden monitoring program using breast milk could be set up in the United States in collaboration with the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). WIC has a large number of lactating first-time mothers: It has 6,000 clinics nationwide and serves almost half (47%) the infants born in the United States. Educational programs (e.g., those run by WIC) are needed that encourage breast-feeding, especially in lower-income communities where breast-feeding rates are low and where breast-feeding may help protect the infant from the effects of environmental chemical exposures. Education is also needed about reducing chemical body burdens. A body-burden monitoring program would provide valuable data on time trends, background levels, and community hot spots in need of mitigation and follow-up health studies; develop analytic methods for new chemicals of concern; and archive breast milk samples for future analyses of other agents.