Presence of environmental chemicals in human milk does not necessarily indicate health risks for infants

Sep 22 2005

The presence of environmental chemicals in human milk does not necessarily indicate health risks for infants, according to researchers.

"We strongly emphasize that the mere presence of an environmental chemical in human milk does not indicate that a health risk exists for breast-fed infants," said Cheston M. Berlin, Jr., M.D., Penn State University professor of pediatrics and pharmacology. "All information gathered to date supports the positive health value of breast-feeding for infants."

Few, if any, adverse effects have been documented as being associated with consumption of human milk containing background levels of environmental chemicals, and none have been clinically or epidemiologically demonstrated, adds Judy S. LaKind, Ph.D., adjunct associate professor of pediatrics, Penn State College of Medicine, Penn State Children's Hospital at Penn State Milton S. Hershey Medical Center. LaKind, Berlin and Michael Bates, University of California at Berkeley, published an overview article of findings from The Second Workshop on Human Milk Surveillance and Biomonitoring for Environmental Chemicals in the United States in the September issue (volume 68, number 20) of Journal of Toxicology and Environmental Health-Part A.

At the workshop, experts from academia, industry, nonprofit organizations and the federal government explored issues related to the use of human milk biomonitoring for environmental chemicals (including a wide range of chemicals to which women may be exposed - industrial chemicals, chemicals in personal care and home/yard products, pharmaceuticals, and recreational and illicit drugs) for understanding human exposure and health, and evaluating and communicating possible human health risk.

Four areas were explored: human milk research designed to answer questions about health; exposure assessment issues; human health risk assessment; and methods for facilitating human milk research.

"Breast-feeding is widely accepted internationally as the gold standard for infant feeding and has unparalleled advantages for both infants and mothers," said Berlin, chair of the workshop and co-author of the journal article. "Advantages for infants include protection from infectious disease, optimal growth including neurodevelopment, and possible protection from certain diseases later in life. It is important to preserve breast-feeding as the best nutrition for infants."

LaKind, guest editor and president of LaKind Associates, LLC, said, "Because human milk provides information on exposures of both the mother and infant, studies on associations with health outcomes for both the mother and infant are possible. One of the points we've tried to make clear is that you cannot present risk-benefit information in a vacuum. That's why we also recommend looking at infant formulas and the chemicals in the water used to make the formulas. An example of this is the potential effects on infants from phytoestrogens - plant compounds with estrogenic activity - in soy-based formulas. In addition, the focus of most human milk biomonitoring studies has been on persistent, bioaccumulative compounds such as PCBs. Little work has been done on shorter-lived chemicals such as volatile chemicals or on chemicals in personal care products."

The panel identified a number of recommendations for future surveillance and research, including:

Determining levels of environmental chemicals found in human milk and infant formula (including water used to prepare formulas and chemicals from synthetic nipples and bottles), with special attention given to those women who may have greater than background exposure;

• Identifying human biomarkers of exposure, susceptibility, and effects to predict potential human health risks associated with specific environmental chemicals in human milk and infant formula;
• Developing methods to analyze the risks and benefits to infants and children exposed to environmental chemicals and endogenous chemicals via breast-feeding and/or formula-feeding;
• Evaluating the usefulness of human milk biomonitoring in identifying agents most likely to be associated with breast disease;
• Researching levels of environmental chemicals in human milk that may occur through occupational exposures;
• Creating an Internet-based database for recording levels of environmental chemicals reported in human milk and infant formula in a standardized manner, with interpretation.

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