FRIDAY, Aug. 4, 2006 (HealthDay News) -- Air fresheners, toilet bowl cleaners, moth balls and other deodorizing products may be easy on the nose but tough on the lungs.
The reason: Exposure to a chemical compound commonly found in such products may cause reduced lung function and have a long-term adverse effect on respiratory health, researchers report.
This finding could be especially important for people with breathing problems, such as asthma, they add.
The study was based on a review of data for 953 adults from the 1988-1994 National Health and Nutrition Examination Survey (NHANES III), which included 200 non-Hispanic whites, 157 blacks and 122 Hispanics. The researchers investigated the relationship between lung function and blood levels of 11 volatile organic compounds (VOCs), which are released as gases by tobacco smoke, cleaning products, paints and thousands of other household products. Examples of these compounds include benzene, styrene, toluene and acetone.
After compensating for smoking habits, the researchers found that one of the compounds -- 1, 4 dicholorobenzene (1, 4 DCB) -- was associated with reduced lung function. Study participants with the highest 1, 4 DCB exposure levels had a 4 percent lower score on a test called FEV1 that measures the amount of air people can exhale in one second.
"Our initial hypothesis was that VOCs in general may be related to reduced lung function, but we were not looking for this one [1, 4 DCB] in particular," said Leslie Elliott, one of the study's co-authors from the National Institute of Environmental Health Sciences.
Although 1, 4 DCB isn't a commonly recognized name, it has a commonly recognized smell because it's the primary ingredient in mothballs, Elliott said. The compound is also found in room deodorizers, urinal and toilet-bowl blocks, and insecticide sprays for moth control.
In the study, blacks had the highest 1, 4 DCB levels, non-Hispanic whites had the lowest levels, and Hispanics were in the middle range. "All of the African-Americans had detectable levels," Elliott said. "It could be that African-Americans and Hispanics use more products that contain 1, 4 DCB, so this is something that needs to be explored."
Although a 4 percent decline in lung function is considered modest, any chronic reduction in lung function is medically significant, Elliott said. "People with asthma and other respiratory illnesses are more affected by any sort of lung irritant," she said. "So until more is known about 1, 4 DCB, people who have respiratory illnesses probably should not use products that contain it."
A previous study showed an association between 1, 4 DCB levels and increased asthma in children. "If people are concerned about 1, 4 DCB products, the safest course would be to reduce their use," Elliott said. "These are not necessary products." Another alternative would be to use air filters instead of air fresheners to remove offensive household odors, she added.
Unfortunately for consumers, 1, 4 DCB may not be listed on product labels. "If you go to a grocery store and look at air fresheners or to an auto-parts store and look at the fresheners that hang from rear-view mirrors, which I've done since this finding, there are no ingredients listed," Elliott said. "In some of my inquiries, I've found that they're proprietary formulas, so they don't actually give out that information."
The study findings are in the August issue of the journal Environmental Health Perspectives.
Attempts were unsuccessful by HealthDay to reach the Research Institute for Fragrance Materials, an industry group that evaluates and distributes scientific data on the fragrant raw materials found in products such as perfumes, cosmetics, shampoos, creams, detergents and air fresheners.
Morton Lippmann is a professor of environmental medicine at New York University School of Medicine. He said, "Since the NHANES population is a representative sample of the U.S. population, it has relevance to the public health risks created by consumer products containing 1, 4 DCB. The blood samples are influenced by chronic exposure, and the persistent reductions in lung function seen in this study, while small, are considered to be indicative of increased risks of chronic respiratory disease later in life."
"Most of the literature on the risks of exposures to VOCs in indoor and/or ambient air is based on hypothetical cancer risks generated by highly conservative risk models," Lippmann added. "This study is noteworthy in that the risk potential is associated with real measurements made using state-of-the-art analyses of VOCs in blood and pulmonary function in the same representative population. The Consumer Product Safety Commission should take note of these findings and consider an action that would reduce exposure to 1, 4 DCB."
Although 1, 4 DCB is associated with reduced lung function, the study researchers said they don't know the compound actually causes the problem. To help answer that question, Elliott hopes to perform a study in which subjects are exposed to normal levels of 1, 4 DCB and then assessed for markers of lung inflammation.
To learn more about volatile organic compounds, visit the U.S. Environmental Protection Agency.