Effects of brominated and organophosphate ester flame retardants on male reproduction

Background Environmental chemicals that interfere with the production and/or action of hormones may have adverse effects on male reproduction. This review focuses on the possible impact of exposure to flame retardant chemicals on male reproduction. Flame retardants are added to a wide variety of combustible materials to prevent fires from starting, slow their spread, and provide time to escape. However, these chemicals are often additive so they leach out into the environment. Governments have restricted the use of polybrominated diphenyl ether flame retardants based on evidence that they are persistent and bioaccumulate and have adverse effects on health. The phasing out of these "legacy" flame retardants has resulted in their replacement with alternatives, such as tetrabromobisphenol A and the organophosphate esters. Objective To review the literature on the effects of brominated and organophosphate ester flame retardant chemicals on male reproduction. Methods PubMed database was searched for studies reporting the effects of brominated and organophosphate ester flame retardants on male reproduction. Results Cell-based, animal model, and human studies provide evidence that the polybrominated diphenyl ethers act as endocrine-disrupting chemicals; further, exposure during critical windows of development may be associated with a permanent impact on male reproduction. In vitro and animal model data are accumulating with respect to the effects of tetrabromobisphenol A and organophosphate esters, but few studies have evaluated their impact on human health. Conclusions More research on human exposure to replacement flame retardants and the possibility that they may be associated with adverse reproductive health outcomes is a high priority.