If you suffer from thyroid, beware of products containing flame retardant chemicals. For, these could adversely impact the functioning of the thyroid gland and make them overly active, results of a new research have indicated. 

Flame retardant chemicals like poly-brominated di-phenyl ethers or PBDE are found in television sets and computer screens, besides in polyurethane foam used for furnishing and carpeting. The research carried out on 270 pregnant women showed that higher PBDE levels in the blood stream caused a fall in the levels of the TSH, a hormone linked to thyroid functioning.

So, women with a higher level of PBDE exposure tended to have more active thyroid glands, says the study published in Environmental Health Perspectives  journal. In fact, patients having low TSH and high levels of the T4 hormone were diagnosed as hyperthyroid, an ailment that often results in miscarriage, birth defects and fetal growth problems amongst pregnant women.

Brenda Eskenazi, who co-authored the study, says that though TSH levels were not low enough to warrant a calamity, the findings prove beyond doubt that PBDE levels in women coming in contact with flame retardant chemicals were comparatively higher than than the overall levels in the United States.

Health concerns over PBDE are not new to the United States as last December the Environmental Protection Agency had announced a phased plan to remove these chemicals. Two of the largest manufacturers of the chemical - Albemarle and Chemtura have signed letters promising to end its use in new electronics products by end of 2010 and in all products by January 1, 2013.

Eskenazi is concerned that the risk of hyperthyroidism could be higher in certain areas with high exposure to the chemicals like in the case of long-time residents of California where flame retardants are ubiquitous with the passage of the state laws in the 1970s.

Critics of the latest study claim that most of the chemicals detected in the research are an older variant known as the pentaBDE that got phased out many years ago. However, Eskenazi believes that PBDEs linger on in human fat tissue and even older products could disintegrate and cause exposure to the chemicals that aggravate the thyroid glands.