Collection and Use of Exposure Data from Human Milk Biomonitoring in the United States

Abstract

Human milk is a unique biological matrix that can be used to estimate exposures in both the mother and the breastfed infant. In addition, the presence of environmental chemicals in human milk may act as a sentinel for exposures to a broader population. Several factors play a role in determining the quantity of chemicals transferred to milk and, subsequently, to the breastfeeding infant, including maternal, infant, and chemical characteristics. Exposure to certain environmental chemicals during critical periods can disrupt normal infant development, yet few data exist to quantify the hazards posed by environmental chemicals in human milk. Chemicals measured in human milk may also provide insights to agents suspect in altering breast development and breast-related disease risk. Carefully designed exposure assessment and toxicokinetic studies are needed to elucidate mechanisms and establish relationships between human milk and other biologic matrices. Data from human milk biomonitoring studies can be used to inform and validate models that integrate information about chemical properties, human metabolism, and biomarker concentrations. Additional research is needed to determine the degree to which environmental chemicals enter, are present in, and are excreted from human milk, their impact on the host (mother), and the extent of their bioavailability to breastfeeding infants. This article describes how the collection and use of exposure data from human milk biomonitoring in the United States can be designed to inform future research and policy. We thank the following organizations for generously providing support for the Workshop: the American Chemistry Council; the Centers for Disease Control and Prevention (C13/CCU323635-01); the Department of Health and Human Services, Health Resources and Services Administration (HHSH240200415021P); Health Canada (H405-03-ExSD079/4500078209); 3M; Pennsylvania State University College of Medicine; the Research Foundation for Health and Environmental Effects; and the U.S. Environmental Protection Agency, Office of Children’s Health (CH-83213101-0). The views expressed in this report are those of the authors and do not necessarily reflect the opinions and/or policies of the U.S. Environmental Protection Agency.