On Tuesday University of California-Berkeley researchers reported that fertility in women can get affected by flame-retardant chemicals. These chemicals are found in household consumer products like foam furniture, electronics, fabrics, carpets, plastics, and other items.

It was found that there is a 30 per cent decline in conceiving every month if there is a 10-fold increase in the blood concentration of four PBDE (polybrominated diphenyl ethers) chemicals.

In the United States these items became common when fire safety standards were adopted. Although they are being phased out some products made before 2004 contain these chemicals.

The research shows that in the U. S. 97 per cent people have detectable levels of this chemical in their blood.

Kim Harley, associate director of the Center for Children's Environmental Health Research at the University of California-Berkeley's School of Public Health, said, "This latest paper is the first to address the impact on human fertility, and the results are surprisingly strong. The chemical leaches into the environment and in California people have really high levels of PBDEs."

In the study, published Tuesday in the journal Environmental Health Perspectives, Harley and other researchers studied the blood samples of 223 pregnant women. They measured PBDE levels.

Researchers though said that it could not be clearly established how PBDEs impact fertility but the chemicals had an affect on neurodevelopment, reduce thyroid hormones, and alter levels of sex hormones.