News Coverage
Researchers find breast milk contaminated
Published February 24, 2005
A toxic chemical linked to birth defects and developmental disorders was found in breast milk samples in Texas and 17 other states, according to a new study by Texas Tech University.
Some of the highest concentrations of perchlorate -- which is normally found in rocket fuels, fireworks and explosives -- were measured in breast milk samples in Texas, according to the study.
Researchers declined to specify in what cities the samples were taken.
The study, billed by researchers as the first survey of perchlorate levels in breast milk, comes less than a week after the federal Environmental Protection Agency unveiled a controversial new safety dose for the contaminant that has been sharply criticized by environmentalists and health advocates as too lenient.
Those criticisms are echoed by the Texas Tech researchers, who concluded "it is obvious" that the new EPA level "will be exceeded for the majority of infants."
The concern is that perchlorate reduces the amount of iodide in the breast milk. That's critical, researchers say, because the thyroid uses iodide to produce hormones essential for normal brain development.
Researchers suggest that the federal government increase the recommended daily dose of iodide for pregnant and lactating women to compensate for perchlorate exposure.
"I think that's a good preventive approach," said Ernest Smith, a toxicologist at Texas Tech and one of the study's authors. "We normally leave those recommendations for medical doctors. But if you ask me my opinion, that's my opinion."
Samples were collected in the fall of 2003 from volunteers nationwide. A second set of samples was collected in early 2004. The researchers tested 36 samples, and all contained at least trace amounts of perchlorate, according to the study.
The highest concentration was nearly 20 times the federally recommended level, and was measured in a breast milk sample in New Jersey.
Most of the regulatory focus on perchlorate has centered on drinking-water contamination near military sites. But the new study indicates that perchlorate has traveled thousands of miles from the original sources of contamination.
Researchers point to the Colorado River, which runs through Texas, as an example of how the contamination can spread.
The river has perchlorate pollution from a plant that manufactured components of missile and rocket propellants. It irrigates nearly 2 million acres that produce 15 percent of the nation's crops and almost as much of its livestock, according to the study.
The Texas Tech researchers said one likely source of perchlorate in breast milk is food, such as lettuce that has been saturated with contaminated water or citrus fruits that have been sprayed with fertilizers containing the contaminant.
Another likely source is dairy milk. The Texas Tech study included 50 samples from grocery stores across the country, and it found traces in all but one, according to the study.
No dairy milk from Texas was tested as part of the latest study. However, Texas Tech researchers in September 2003 tested seven samples of milk from grocery stores in Lubbock and found perchlorate in all seven.
"It's clear that women across the country have perchlorate in their breast milk," said Renee Sharp, a senior analyst with the Environmental Working Group in Oakland, Calif. "I have to say that even as a person who's been working on this issue now for four and a half years, who knows this issue inside and out, I was surprised."