News Coverage
Studies find mothers' milk carries industrial chemicals
Despite discovery, doctors urge continued breastfeeding
Published September 22, 2003
The breast milk of U.S. mothers is delivering something besides nutrition: the world's highest levels of a type of industrial chemical linked to serious health risks.
The chemicals are brominated flame retardants, widely used in foam furniture cushions and in electronic equipment such as televisions and computers. As their use in the United States has soared in recent years, levels have risen dramatically in soil, fish, marine mammals and people.
When University of Texas scientists recently tested breast milk samples from 47 women in Dallas and Austin, they found that all were contaminated.
Another study, to be released Tuesday by an environmental group, found nearly identical results from the breast milk of 20 first-time mothers from 14 states: Every woman was passing the chemicals on to her baby.
Despite the findings, doctors say that women should keep breastfeeding their babies, and do so as long as possible. Studies have found that breastfeeding isn't the biggest source of exposure, because babies have adult-size exposures before birth because contamination in the mother crosses the placenta into the fetus.
Research shows that breastfeeding actually reduces the chemicals' effects and delivers benefits from natural nutrients, said Sonya Lunder, co-author of the national study.
Both the Texas and national studies found higher levels than any previous studies. Scientists speculate that increased industrial use of the chemicals in the United States might be to blame.
Engineers have long documented the benefits of brominated flame retardants, which save thousands of lives and millions of dollars a year by slowing the spread of fire. But doctors are just now beginning to understand their effects on people's health. The Texas and national studies are the first to examine levels in individual American mothers' milk.
Almost no direct research on health effects among people has been done. Many animal studies have linked some types of the substances to thyroid disorders and disrupted brain development, especially in the crucial periods before birth and in early infancy.
The federal government's National Toxicology Program says the substances are "reasonably anticipated" to cause cancer in people.
"These are poisons," said one of the Texas study's authors, Dr. Arnold Schecter of the University of Texas School of Public Health's Dallas branch. "And breast milk is 100 percent of the baby's diet. It's got to be stopped."
A spokesman for the chemicals' makers said the health-risk claims are unproven.
"None of these fire retardants has ever been proven to have any health effects on people," said Peter O'Toole of the Bromine Science and Environmental Forum.
Whether the chemicals are harmful or not, the well-established benefits of breastfeeding still apply, Ms. Lunder said.
"We are not putting this burden on parents to decide how to feed their babies," Ms. Lunder said.
Instead, she said, the goal is to reduce contamination levels in the environment.
A Texas mother who took part in the national study agreed.
"My husband and I talked about it," said Leila Feldman, 30, an Austin attorney whose son, Max, is 5 months old. "It did give us some pause, but after doing the research, we feel that there are still significant health benefits in breastfeeding."
The Texas study, which has been accepted for publication in the federal research journal Environmental Health Perspectives, was a joint project of the University of Texas School of Public Health's Dallas branch and UT Southwestern Medical Center in Dallas.
The national study was done by the Environmental Working Group, an investigative and advocacy group based in Washington, D.C.
The national study was not published in a peer-reviewed journal but was reviewed in advance by Dr. Linda Birnbaum, chief toxicologist for the U.S. Environmental Protection Agency, and other scientists.
Some American health experts are calling for the United States to follow Europe's example and limit or ban the use of the most toxic forms of brominated flame retardants. They say manufacturers can use alternatives that guard against fire with fewer health risks.
Mr. O'Toole, the industry spokesman, said manufacturers were investing in alternatives but replacements weren't widely enough available yet.
Still unclear is how the chemicals are getting into people's bodies, either by food or other means.
Some studies suggest that eating higher-fat fish, such as salmon, might be a factor, because the chemicals build up in fatty tissues.
Dr. Schecter said more basic research and clinical advice for nursing mothers are needed, but funds are scarce.
Manufacturers use flame retardant chemicals in sofa cushions, upholstery fabrics and plastics, including the shells and printed circuit boards of home computers and the trim in cars.
The Texas study was the first to examine the breast milk of individual women. Previous investigations looked at pooled samples from several women.
Out of the 47 women tested, all had brominated flame retardants in the fat of their breast milk at an average level of 73.9 parts per billion.
The national study also tested individual women's milk. All the samples contained the chemicals, with an average level of 159 parts per billion.
The highest average level found previously was 40 parts per billion in a Canadian study. Levels in Europe and Asia are far lower, though researchers documented big increases in the 1990s as use of the chemicals jumped.
---------------------------------Brominated flame retardants
The chemicals are added to consumer products ranging from televisions to foam cushions. They save lives and property by slowing the spread of fire. Production of the chemicals has jumped in recent decades because of increased demand.
* That jump has been accompanied by sharp rises in levels of the chemicals found in people.
* Animal studies have linked some types of brominated flame retardants to cancer, nervous system disorders, endocrine system disruption and developmental problems in people.
* Europe has ordered a partial phaseout of the chemicals. California and Maine have taken limited action. There are no restrictions in Texas or nationwide.
Breastfeeding
Brominated flame retardants have been found in all samples of American mothers' breast milk tested so far. But experts say the known benefits of breastfeeding far outweigh any concerns over contamination.
* Breastfeeding reduces a baby's risk of serious diseases such as asthma, diabetes and cancer, as well as infectious diseases. It also benefits the mother, lowering rates of ovarian and breast cancer.
* Studies also show that breastfeeding offers extra protection against the health risks posed by environmental contaminants. Because exposure to brominated flame retardants has already occurred before birth, breastfeeding only benefits a baby.
For more information:
* University of Texas School of Public Health and UT Southwestern
Medical Center study: http://ehpnet1.niehs.nih.gov/docs/ 2003/6466/abstract.pdf* Environmental Working Group study: www.ewg.org
* American Academy of Pediatrics breastfeeding Web site: www.aap.org/family/brstguid.htm
* Bromine Science and Environmental Forum (industry site): www.bsef.com