Effects of Polybrominated Diphenyl Ethers on Hormonal and Reproductive Health in E-Waste-Exposed Population: A Systematic Review

Abstract

Electronic waste management is a global rising concern that is primarily being handled by informal recycling practices. These release a mix of potentially hazardous chemicals, which is an important public health concern. These chemicals include polybrominated diphenyl ethers (PBDEs), used as flame retardants in electronic parts, which are persistent in nature and show bioaccumulative characteristics. Although PBDEs are suspected endocrine disruptors, particularly targeting thyroid and reproductive hormone functions, the relationship of PBDEs with these health effects are not well established. We used the Navigation Guide methodology to conduct a systematic review of studies in populations exposed to e-waste to better understand the relationships of these persistent flame retardants with hormonal and reproductive health. We assessed nineteen studies that fit our pre-determined inclusion criteria for risk of bias, indirectness, inconsistency, imprecision, and other criteria that helped rate the overall evidence for its quality and strength of evidence. The studies suggest PBDEs may have an adverse effect on thyroid hormones, reproductive hormones, semen quality, and neonatal health. However, more research is required to establish a relationship of these effects in the e-waste-exposed population. We identified the limitations of the data available and made recommendations for future scientific work.

Flame Retardant Exposure in Vehicles Is Influenced by Use in Seat Foam and Temperature

“…Polybrominated diphenyl ethers (PBDEs) were extensively used in furniture, electronics, and vehicles until the early 2000s, when their use began being restricted due to negative health effects and persistence in the environment . PBDE exposure in humans has been associated with developmental neurotoxicity, thyroid hormone dysregulation, and reproductive toxicity . Although certain FR classes, including PBDEs, have been restricted for use in consumer products in the United States, the use of nonrestricted FRs is still the most affordable way to comply with flammability standards.…”

“… 9 PBDE exposure in humans has been associated with developmental neurotoxicity, 10 thyroid hormone dysregulation, 11 and reproductive toxicity. 12 Although certain FR classes, including PBDEs, have been restricted for use in consumer products in the United States, 13 the use of nonrestricted FRs is still the most affordable way to comply with flammability standards. Other FRs, such as alternative brominated flame retardants (BFRs) and organophosphate ester flame retardants (OPEs), are now commonly used to replace phased-out compounds.…”

Halogen Bonding Interactions of Haloaromatic Endocrine Disruptors and the Potential for Inhibition of Iodothyronine Deiodinases

“…[28,29] These persistent organic pollutants (POPs) have made their way into the food chain through chemical spills and leaching from waste including electronic waste and microplastics. [30][31][32][33] Although the primary pathway for PHAH endocrine disruption appears to be through inhibition of the aryl hydrocarbon receptor (AhR), [34] they may also affect TH activation by Dio proteins. Halogen bonding of PHAHs to the Dio active site selenocysteine (Sec) residue to prevent TH binding and activation is a potential mechanism for Dio inhibition, [35] which has been demonstrated for polychlorinated biphenyls (PCB) and polybrominated diphenyl ethers (PBDE).…”

“…PHAHs have primarily been used as flame retardants in a variety of industrial applications [28,29] . These persistent organic pollutants (POPs) have made their way into the food chain through chemical spills and leaching from waste including electronic waste and microplastics [30–33] . Although the primary pathway for PHAH endocrine disruption appears to be through inhibition of the aryl hydrocarbon receptor (AhR), [34] they may also affect TH activation by Dio proteins.…”