Polybrominated Diphenyl Ethers (PBDEs)

Polybrominated diphenyl ethers (PBDEs) are flame retardants used in a variety of consumer products, which have become ubiquitous environmental contaminants. Concentrations of PBDEs are particularly high in breast milk, resulting in high exposure of infants; for toddlers, dust has been estimated to account for a large percentage of exposure. PBDEs can also cross the placenta, as they have been detected in fetal blood and liver. Tetra-, penta-, and hexa-BDEs are most commonly present in human tissues. The current greatest concern for potential adverse effects of PBDEs relates to their developmental neurotoxicity, particularly in the domains of locomotor activity and cognition. Alterations in circulating thyroid hormone homeostasis and direct effects of PBDEs on the developing brain may represent underlying mechanisms.