Chemical in Air Fresheners Impairs Lung Function

RESEARCH TRIANGLE PARK, North Carolina, July 27, 2006 (ENS) - A chemical compound found in many air fresheners, toilet bowl cleaners, mothballs and other deodorizing products, may be harmful to the lungs, according to a new study by U.S. government researchers.

Human population studies at the National Institute of Environmental Health Sciences (NIEHS), a part of the National Institutes of Health, found that exposure to a volatile organic compound called 1,4 dichlorobenzene (1,4 DCB) may cause "modest reductions" in lung function.

"Even a small reduction in lung function may indicate some harm to the lungs," said NIEHS researcher Stephanie London, M.D., lead investigator on the study. "The best way to protect yourself, especially children who may have asthma or other respiratory illnesses, is to reduce the use of products and materials that contain these compounds."


NIEHS researcher Stephanie London, M.D., a specialist in genetic epidemiology, was lead investigator on the 1,4 DCB study. (Photo courtesy NIEHS)
Volatile organic compounds, VOCs, are compounds emitted as gases from thousands of commonly used products, including tobacco smoke, pesticides, paints, and cleaning products. VOCs are also released in automotive exhaust.

This particular VOC, 1,4 DCB, is a white solid compound with a distinctive aroma, similar to mothballs. It is typically used as a space deodorant in products such as room deodorizers, urinal and toilet bowl blocks, and as an insecticide fumigant for moth control.

The researchers examined the relationship between blood concentrations of 11 common volatile organic compounds and lung function measures in a representative sample of 953 adults 20 to 59 years old. Four measures of lung function were used in the analyses.

They found that of the common VOCs analyzed, including benzene, styrene, toluene, and acetone, only the compound 1,4 DCB was associated with reduced lung function.

This effect was seen even after careful adjustment for smoking.

The researchers found that 96 percent of the population sampled had detectable 1,4 DCB blood concentration levels. African Americans had the highest exposure levels and non-Hispanic whites the lowest.


Deodorant blocks such as these contain 1,4 DCB, a volatile organic compound that reduces lung function. (Photo credit unknown)
"Because people spend so much time indoors where these products are used, it's important that we understand the effects that even low levels might have on the respiratory system," said Leslie Elliott, Ph.D. a researcher on the NIEHS-funded study.

"There has been very little research on the health effects of this particular compound in non-occupational settings," Eilliott said.

The researchers used data from the third National Health and Nutrition Examination Survey, a nationally representative survey conducted by the Centers for Disease Control and Prevention between 1988-1994 to determine the health and nutritional status of the U.S. population.

They focused on a special component of the study designed to assess the level of common pesticides and VOCs in the U.S. population, and found that increasing blood concentrations of 1,4 DCB corresponded with reductions in pulmonary function.

The researchers also assessed the influence of other factors in an individual's environment that may be related to lung function and to 1,4-DCB exposure - type of heating, use of wood fires, age of house, presence of furred pets, occupation, socioeconomic status, environmental tobacco smoke, smoking history, and diagnosis of asthma or emphysema.

"This research suggests that 1,4-DCB may exacerbate respiratory diseases," said NIEHS Director David A. Schwartz, M.D, who is also a specialist in environmental lung disease. "As part of the new disease-focused approach at NIEHS, researchers will use this information to better understand the pathogenesis of respiratory diseases."

The NIEHS introduced a new strategic plan in May aimed at challenging and energizing the scientific community to use environmental health sciences to understand the causes of disease and to improve human health.

The plan, "New Frontiers in Environmental Sciences and Human Health," is online at:

The study, "Volatile Organic Compounds and Pulmonary Function in the Third National Health and Nutrition Examination Survey, 1988-1994," is published in the August issue of "Environmental Health Perspectives."

The National Institute of Environmental Health Sciences, a component of the National Institutes of Health, supports research to understand the effects of the environment on human health, online at: