FOR IMMEDIATE RELEASE
March 1, 2006

CONTACT: Jim Tobin
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Study Identifies Potential Residential Mercury Threat
Report in Environmental Health Perspectives details exposure from replacement of older gas regulators in the home

Careless replacement of older gas regulators can result in household mercury contamination, according to a study recently accepted for publication in Environmental Health Perspectives. Residents in Chicago were exposed to mercury in 2000 when a gas company removed and replaced their gas regulators and meters. Urine analysis later revealed the presence of mercury in some of these individuals.

Gas regulators reduce pressure from main gas feeder lines to household pipes. Although newer gas regulators do not contain mercury, units made before 1961 contained an average of 2 teaspoons of elemental mercury and were often installed in basements. When these older units are replaced, the mercury can spill onto the floor, and residents can inhale the mercury vapor. In a 2001 inspection of 361,000 Chicago homes where old gas regulators had been replaced, a total of 1,363 homes were found to be contaminated.

In the current study, the researchers studied urine samples of 625 residents of the contaminated Chicago homes who elected to undergo mercury screenings. Nine of the residents (1.4%) had a 24-hour urine mercury concentration equal to or higher than 10 µg/L. None of the individuals overt symptoms of mercury poisoning, but the screenings were not designed to detect subclinical effects of mercury exposure.

Even though air mercury concentrations were considerably higher in basements, where the spills typically occurred, positive urine mercury in residents was most strongly associated with air mercury concentrations on the first floor of the homes examined. The authors attribute this finding to people generally spending less time in their basements.

The authors note that gas companies and their contractors, clinicians, public health and environmental officials, and residents all need to be aware of the potential for contamination in older homes or other buildings where mercury-containing gas regulators have been replaced in the past, or where they may still exist. They also write that "guidelines and protocols developed for this Chicago-area response may be helpful tools for public health officials who may be faced with developing future public health responses to large-scale residential mercury exposures."

The lead author of the study was Daniel Hryhorczuk of the Great Lakes Center for Children's Environmental Health. The other authors were Victoria Persky, Julie Piorkowski, Jennifer Davis, C. Michael Moomey, Anne Krantz, Ken D. Runkle, Tiffanie Saxer, Thomas Baughman, and Ken McCann. Funding for the study was provided by the Association of Occupational and Environmental Clinics, the Agency for Toxic Substances and Disease Registry, and the U.S. Environmental Protection Agency. The article is available free of charge at http://www.ehponline.org/docs/2006/8401/abstract.html

EHP is published by the National Institute of Environmental Health Sciences (NIEHS), part of the U.S. Department of Health and Human Services. EHP EHP is an Open Access journal. More information is available online at http://www.ehponline.org/. Brogan & Partners Convergence Marketinghandles marketing and public relations for EHP, and is responsible for the distribution of this press release.

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