Halogenated Flame Retardants(HFRs) are added in to materials to improve their resistance to heat and flames. This family of chemicals includes Polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), Tetrabromobisphenol A (TBBPA), chlorinated tris, and many others. Unfortunately, many of these chemicals can enter the human body and may also cause health problems.
People are exposed to HFRs in many ways, but house dust, food and air seem to be the major sources of exposure. Many HFRs are very stable chemicals and can remain in your body for months or years, so frequent small exposures can build up into higher levels in your body over time.
The Center for Disease Control and Prevention(CDC) has published several studies on the levels of flame retardants in the U.S. population. Flame retardants have been found in more than 90 percent of the U.S. population, with PBDEs generally having the highest concentrations. In general, flame retardant levels are about 20 times higher in the U.S. population than other countries.
Children are more vulnerable to HFR exposure. Unfortunately, there is evidence that HFRs can be transferred from mothers to their children through the placenta and also through breast milk. HFRs also hitch a ride on dust into small children's bodies during normal hand to mouth behavior. In the US, levels of flame retardant PBDEs are higher in children than in adults.
Once inside of your body, there is potential for halogenated flame retardants to cause health problems. Some halogenated flame retardants can change how young brains develop during pregnancy and childhood. These changes can cause problems with learning and cognitive processes later in life. Exposure to PBDEs in the womb has been associated with decreased IQ, attention deficits, and poor motor development in children.
Flame retardants such as PBDEs and chlorinated tris may also cause reproductive problems. In some studies, men who live in homes with high HFR concentrations have had lower sperm counts. High levels of PBDEs in breast milk have been associated with undescended testicles in male infants. One study found that women with more PBDEs in their bodies took longer to get pregnant, suggesting these chemicals may impact a woman's ability to conceive a child.
Some HFRs are known to interfere with hormones in the body, these chemicals are called endocrine disruptors. People living in homes with high HFR levels in dust have been found to have lower thyroid hormone levels and lower levels of prolactin (a hormone that helps regulate dopamine). High levels of PBDES in house dust are also associated with lower concentrations of testosterone and other male hormones. Some studies have found that children born to mothers with high PBDEs levels in their bodies had lower thyroid hormone levels.
Some HFRs increase the risk of cancer. Chlorinated Tris, one of the most highly used flame retardants in the U.S, causes mutations in DNA which may lead to cancer. HFRs may also promote the growth of existing cancers by mimicking hormones that stimulate the growth of cancer cells.