Tuesday, October 6, 2009

Chemical solvent in Cape Cod drinking water may be causing birth defects

From the Cape Cod Times:

A new study published in an environmental health journal says babies born to Cape women exposed in pregnancy to a chemical solvent in drinking water had an increased risk of birth defects.

A mother's exposure to PCE, also known as perchlorethylene, increased by threefold the risk a baby would have cleft palate or a neural tube defect, said lead researcher Ann Aschengrau, an epidemiologist at the Boston University School of Public Health.

She worked with a team of researchers to study women from eight Cape towns who had been exposed to PCE in the vinyl lining of water pipes from 1969 to 1983.

Evidence is mounting that PCE, a solvent often used in dry cleaning, has an impact on fetal development, Aschengrau said. "Pregnant women are a vulnerable population. We really need to find out the effects of these chemicals among them."

Water contamination typically results from industrial disposal, but in the 1960s water pipes in several towns on the Cape and elsewhere in Massachusetts were purposely sprayed with vinyl plastic and PCE to improve the taste of drinking water, Aschengrau said.

Manufacturers wrongly assumed the PCE would disappear during the drying process, but large amounts remained and slowly leached into drinking water in Barnstable, Bourne, Falmouth, Mashpee, Sandwich, Provincetown, Brewster and Chatham, she said.

Aschengrau's study is important because it is able to single out PCE exposure as a risk factor, said Julia Brody, executive director of the Silent Spring Institute in Newton, which researches environmental links to breast cancer.

Since people are exposed to a variety of chemicals throughout their lives, it's hard to link health conditions to specific contaminants, Brody said. "It's very difficult to measure how much different people are exposed to at different points in life," she said.

But the PCE in the water pipes created "a much more clear exposure than you typically get in a health study," Brody said.

Once the PCE contamination was detected, authorities cleared the pipes through a flushing process, saying replacing hundreds of miles of vinyl-coated pipe would be too expensive, Aschengrau said.

For her five-year study, researchers got records of where the coated pipe had been installed and used birth certificate records to track down women who'd used those water supplies during their pregnancies in a 15-year time period.

"We spend a lot of time looking for everybody," Aschengrau said. She said 70 percent of the women contacted, or 2,046, responded to the researchers' questionnaires.

Cleft palate and neural tube defects were the only birth defects that stood out among the babies who had been exposed in the womb to PCE.

Cleft palate occurs when the palate doesn't close completely. Neural tube defects affect the brain and spinal cord. The two most common neural tube defects are spina bifida, which ranges from mild to severe, and anencephaly, which occurs when part of the brain is missing; it is always lethal.

The number of children with these defects was small — 17, including those exposed and unexposed to PCE. Aschengrau said she'd like to do a follow-up study of PCE water pipe exposure across Massachusetts in order to obtain a bigger sample size.

Her research was funded by the National Institute of Environmental Health Sciences.