If you are trying to get pregnant, get off your couch.

Odds are your furniture is covered with PBDEs, a type of flame retardant commonly found in household consumer products. According to a new University of California Berkeley study, women with higher blood levels of PBDEs took longer to become pregnant than women with lower PBDE levels.

PBDEs, or polybrominated diphenyl ethers, are a class of organobromine compounds that became commonplace after the 1970s when new fire safety standards were implemented in the United States. The flame retardants are used in foam furniture, electronics, fabrics, carpets, plastics and other common items in the home.

“There have been numerous animal studies that have found a range of health effects from exposure to PBDEs, but very little research has been done in humans,” the UC Berkeley researchers say.

This latest paper, published January 26 in the journal Environmental Health Perspectives, found that each 10-fold increase in the blood concentration of four PBDE chemicals was linked to a 30 percent decrease in the odds of becoming pregnant each month.

“It is the first paper to address the impact on human fertility, and the results are surprisingly strong,”said the study's lead author, Kim Harley, adjunct assistant professor of maternal and child health and associate director of the Center for Children's Environmental Health Research at UC Berkeley's School of Public Health. “These findings need to be replicated, but they have important implications for regulators.”

Studies have found widespread contamination of house dust by PBDEs, which are known to leach out into the environment and accumulate in human fat cells.

Previously studies also suggest that 97 percent of U.S. residents have detectable levels of PBDEs in their blood, and that the levels in Americans are 20 times higher than in their European counterparts.

According to the researchers, residents in California are among those experiencing the highest exposures, most likely due to the state's relatively stringent flammability laws.

Although researchers are not entirely clear how PBDEs might impact fertility. A number of animal studies have found that PBDEs can impair neurodevelopment, reduce thyroid hormones, and alter levels of sex hormones. Both high and low thyroid hormone levels can disrupt normal menstrual patterns in humans, but this study did not find a link between PBDE exposure and irregular menstrual cycles.

A 2007 University of Birmingham study found flame retardants containing bromine can harm humans by lowering sperm counts cells, and it was also linked to a wide range of diseases from cancer and diabetes to auto-immune syndromes to asthma and eczema.

“Brominated flame retardants are known endocrine disrupters, interfering with the body’s glands, and adversely affecting hormones such as estrogen and testosterone in humans,” said Dr. Francesco Michelangeli, University of Birmingham School of Biosciences, who authored the 2007 study.

There are some 209 different possible formulations of PBDEs, but only three mixtures – pentaBDE, octaBDE and decaBDE – have been developed for commercial use as flame retardants. Like many other studies, the most prevalent PBDEs in the blood of women participating in the UC Berkeley study were four components of the pentaBDE mixture.

Last month, three large chemical companies that produce and use the toxin, in cooperation with the Environmental Protection Agency (EPA), have arrived at a voluntary agreement to stop producing DecaBDE by December 2012 and eliminate its usage completely in 2013.

Consumer advocates say voluntary agreements seldom produce lasting effects. Unless a congressional act to reform the nation’s toxic chemical laws is passed, each state will have to legislatively ban the chemicals one by one.

In 2007, state assembly bill that would have banned all brominated and chlorinated chemical flame retardants from household furniture and bedding sold in California failed to pass.

The National Institute of Environmental Health Science, the U.S. EPA and the CDC helped support the UC Berkeley research.

Lynette Summerill, is an award-winning journalist who lives in Scottsdale, Arizona. In addition to writing about cancer-related issues, she writes a blog, Nonsmoking Nation, which follows global tobacco news and events.