In September 2003, the Environmental Working Group (EWG), a non-profit environmental health research and advocacy organization, released study findings that detected the highest levels of flame retardants in breast milk
ever recorded. EWG collected breast milk samples from women around the country—from Seattle, Washington to
Gainesville, Florida—and sent them to an independent testing lab for analysis. The results yielded an alarming but not entirely unexpected outcome: Every mother tested had detectable levels of a class of flame retardants in their breast milk, most at levels that cause fetal damage in animal experiments.
Flame retardants known as polybrominated diphenyl ethers, or PBDEs, have become ubiquitous in the environment,
wildlife, and humans since the 1970s when production began on a large scale. They persist in the environment
and are known to bioaccumulate in the human body. PBDEs replaced polybrominated biphenyls after an incident
that exposed 9 million people to tainted meat and dairy products after cattle feed became contaminated. The U.S. is the largest consumer of PBDEs, using 73 million pounds in 2001 alone.
PBDEs are neurotoxic and interfere with thyroid function in laboratory experiments. The chemicals depress T3
and T4 hormones, which help regulate normal metabolism. Maternal suppression of these hormones has been associated with lower IQ scores. Exposure during critical periods of development has been linked to motor and other neurological deficits.
Importantly, researchers agree that exposure in-utero is more harmful than exposure during breastfeeding. In fact,
several studies show that breast milk can mitigate the effects of in-utero exposure to harmful substances. A longitudinal study of Michigan mothers who were exposed to PCBs while pregnant (the chemical cousins of PBDEs) demonstrated that breastfed infants were less likely to exhibit effects of PCB exposure than their formula-fed counterparts
The message pregnant and breastfeeding women should take home is that breastfeeding is always preferable to formula feeding. The problem lies in a flawed regulatory system that does not adequately test chemicals for a full range of health effects before they are allowed on the market. The EWG study results should encourage women of childbearing age to advocate for reformation of chemical policy and regulation, as chemicals such as PBDEs should not be allowed to trespass in the human body. This year California chose to phase out two types of PBDEs. The entire nation should follow suit.
Biomonitoring breast milk is an important research tool and indicator of fetal exposure. Since breast milk is high
in lipids, it is also the least invasive way to measure chemicals known to bioaccumulate in fat, as opposed to extracting tissue samples from people. Biomonitoring programs supported by the Centers for Disease Control and
California Department of Health Services should be expanded, as they give valuable, scientific proof that chemicals are showing up where they should not be—in our blood, urine, and breast milk.
If you would like to read the EWG report, Mother’s