Researchers Find EDC Levels Are Higher Indoors Than Outdoors
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Aug. 5, 2010 -- Concentrations of endocrine-disrupting chemicals (EDCs) -- found in many everyday products and of concern due to potential health hazards -- are higher indoors than outdoors, according to a new study.
But they are equally present, the researchers found, in an urban, low-income community near an oil refinery and in a rural, affluent coastal community without much industry.
"The higher your exposure to consumer products, the higher your exposure to endocrine-disrupting chemicals," researcher Ruthann Rudel, director of research at the Silent Spring Institute, Newton, Mass., tells WebMD.
"The indoor consumer product exposure [to these chemicals] is more pervasive and consistent than we thought," she says of the study findings. "It cuts across geography and demography, based on this somewhat limited sample."
The study is published online in Environmental Science & Technology.
Taking Samples of EDCs
Rudel and her colleagues sampled indoor and outdoor air in two communities in the San Francisco Bay area. They looked for 104 compounds, including 70 suspected EDCs.
EDCs can mimic or disrupt the body's natural hormone system, Rudel says. As a result, they can hamper cell growth and development.
Rudel's team conducted the samplings in 2006 in Richmond, Calif., a low-income, urban industrial community and in Bolinas, Calif., a coastal community that is affluent and without much industry. They took samples from 40 Richmond homes and 10 Bolinas homes.
The researchers found 39 chemicals outdoors and 63 indoors, including phthalates, parabens, PBDE flame retardants, PCBs, and pesticides.
The chemicals are found in such products as detergents, furniture, carpets, electronic equipment, pesticides, cosmetics, and building materials.
Higher indoor concentrations compared to outdoor were found for 32 of the EDCs, Rudel found, and only two of the EDCs were more common outdoors.
Indoor levels of EDCs were more similar than outdoor for the two communities.
The new findings, Rudel tells WebMD, "build on a study we did in Cape Cod in 2003." But that East Coast study was entirely conducted indoors.
"This study demonstrates that chemicals from consumer products affect indoor air quality and exposures are ubiquitous," Rudel says in a written statement.
And some research has shown adverse health effects from typical exposure levels to such EDCs as phthalates, and flame retardants, she says. But, she says, more study is needed.
The sampling, she tells WebMD, may not reflect true exposure to a specific person. "These results reflect what is in the air, not what is on your body," she says.
Using a soap with EDCs, for instance, could result in higher levels on your skin than what is in the air, she says, as could skin contact with a fabric with stain-resistant coating.
It's important to collect exposure information, Rudel says, so regulatory agencies can focus their priorities on EDCs with high or common exposure and decide if control is needed.
Manufacturers can also use the information to make decisions about product formulations, she says, and consumers armed with this information can decide what to buy.
The new findings add evidence to what some scientists have long suspected, says Charles J. Weschler, PhD, adjunct professor of environmental and occupational medicine at the University of Medicine and Dentistry of New Jersey and continuing visiting professor at the Technical University of Denmark in Copenhagen.
"It drives home the fact that a lot of these compounds that are potentially endocrine-disrupting are entering our bodies in part as a consequent of indoor exposures," he tells WebMD, although he says that some do come from food and drink as well.
"When you look at the indoor concentrations of some of these compounds," he says of the study findings, "it doesn't matter whether you live next to a refinery or in the woods."
In a study he conducted in 1984, Weschler says he measured some of the same compounds. "In 1984, we didn't realize these compounds were potential EDCs," he says. Back then, they regarded the compounds as additives that were used in a host of products.
"I think this paper is alerting those who really were not aware of the fact that indoor exposures really matter for a lot of these compounds," he says.
"When you buy that new shower curtain with the strong smell [from plasticizers], some of those chemicals are going to end up in you," he says.
How to Avoid EDCs
Research is ongoing, and until more is known, Rudel says concerned people can take a few measures to reduce potential exposure to the compounds.
- Use fewer products overall, such as cleaning products and cosmetics, that contain EDCs.
- Avoid fabrics coated with anti-stain chemical.
- Avoid use of antibacterial soaps, which contain triclosan, an EDC.
SOURCES: Ruthann Rudel, director of research, Silent Spring Institute, Newton, Mass.
Rudel, R. Environmental Science & Technology, published online Aug. 3, 2010.
Charles Weschler, PhD, adjunct professor of environmental and occupational medicine, University of Medicine and Dentistry of New Jersey; continuing visiting professor, Technical University of Denmark, Copenhagen.
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