Indoor air is becoming polluted by powerful household chemicals


From Pittsburgh Post-Gazette

Tuesday, December 23, 2003

By Don Hopey, Post-Gazette Staff Writer

A recent study has found the dust and air trapped inside homes is likely to contain a wide variety of human reproduction-disrupting and cancer-causing chemicals. These chemicals are found in common consumer products and exposure to them could affect the health of every family member, especially those who are female.

The study of air and dust samples taken from 120 homes on Massachusetts’ Cape Cod found chemicals in window cleaners, laundry detergents, cleaners, spot removers, hair dyes, nail polishes, plastics, electronics, and flame retardant carpeting and furniture turned up in potentially harmful levels.

“It appears that high-income women might be exposed to more chemicals through their personal health-care products and household cleaning products,” said John Spengler, professor of environmental health in the Harvard Schoolof Public Health, and a co-author of the study.

He said he expects studies of indoor air in lower-income housing would show higher exposures to chemicals contained in pesticides.

In-home contaminants are significant contributors to people’s overall exposure and can have a big impact on health because people in the United States and most industrialized countries spend 65 percent of their time in their residences, studies show.

Women are more likely to be affected because they typically spend more time inside the home and work more closely with potentially toxic cleaners and personal care products like hair dyes and nail polish, Spengler said.

Women’s bodies also contain as much as 10 percent more body fat than men’s and so are able to store more fat-soluble toxins and synthetic chemicals. These then can be transferred to children in utero and through breast milk.

Overall, the study detected 66 chemical compounds in the dust and measured 52 in the air. On average, the dust in the tested homes contained 26 compounds and the air contained 19. Spengler said the levels measured in Cape Cod are not significantly higher than elsewhere in the country.

The study, published in the September issue of Environmental Science & Technology, is the most comprehensive indoor air analysis to date. It is part of the Silent Spring Institute’s ongoing Cape Cod Breast Cancer and Environment Study.

“The surprising finding was how many chemicals we found in every house,” Spengler said. “They all had more than 20 compounds and some of the compounds are banned substances. In addition we measured 30 compounds never reported in residential settings before.”

One of those unreported chemical compounds is 4-nonylphenol, an alkylphenol found at significant levels in every home sampled. Laundry detergents, disinfecting cleaners, all-purpose cleaners, hair-coloring and other hair careproducts and spermicides contain this product.

The chemical can mimic female estrogen hormones, and can interact and disrupt the endocrine systems of humans and wildlife, interfering with reproduction and causing increased risk of birth defects and breast, prostate and testicular cancers.

Although the European Union restricts 4-nonylphenol use, there are no U.S. Environmental Protection Agency guidelines for human exposure to it or any other chemicals based on their endocrine activity. The EPA and the chemicals’ manufacturers have indicated that it would not become airborne.

Barbara Losey, deputy director of the Alkylphenols & Ethoxylates Research Council, an industry-funded organization, said the levels of alkylphenols found by the study in the dust and air are too low to disrupt reproductive processes.

“It’s interesting to look at indoor air because its an area that hasn’t been looked at much and respiratory exposure to nonylphenol hasn’t been looked at as much compared to other routes,” Losey said. “But our research still leads us to conclude that human exposure is very low.”

But Spengler said not enough is known about the residential risks posed by such exotic compounds.

“We’ve made measurements of chemical compounds that are possible endocrine disrupters,” Spengler said. “When we see these levels it should be a wake-up call to get more research going.”

There are no federal regulatory standards for contaminants in indoor air and house dust. The EPA has issued exposure guidelines for about half the compounds detected in the Cape Cod study and most of those were measured in concentrations below those standards.

But 15 compounds were measured in levels that exceeded the standards, including one given off as a vapor from plastics and some pesticides and polychlorinated biphenyls, or PCBs, that are banned from current use.

Spengler said carpeting and newer, air-tight houses accentuate the risk because they hold the contaminants in the home for a longer time.

When outdoor air pollution was much worse it overshadowed indoor air problems, he said. As outdoor air quality has improved, problems with indoor air pollutants, which have gotten more chemically complex over the years, have emerged.

“We’ve eliminated or reduced many combustion based pollutants outside,” Spengler said, “but things like plastics, flame retardants, cosmetics, pesticides and cleaning chemicals no one’s looked at,”

But there is no doubt that Americans are exposed to thousands of chemicals every day in their homes and workplaces.

The Centers for Disease Control and Prevention this year released its second annual report on human exposure to environmental chemicals, cataloging chemicals found in the blood and urine of folks in a national sample.

“We measured 116 and there are others likely in the body,” said Dr. John Osterloh, chief medical officer of the CDC’s Environmental Health laboratory and a co-author of the exposure report. “For the most part their magnitude and concentrations are not that high, but we really don’t have standards for many of the chemicals we tested.”

Osterloh said the report will help direct researchers to the chemicals that are present in humans and, based on their concentrations, the ones that they need to assess for health effects.

The chemicals identified in the CDC report are emitted from carpeting on floors, paint on walls, building materials in ceilings, even the desk chairs people sit in. They seep imperceptibly into the air and are breathed into the lungs.