Non-Dioxin-Like Polychlorinated Biphenyl Neurotoxic Equivalents Found in Environmental and Human Samples.

Non-Dioxin-Like Polychlorinated Biphenyl Neurotoxic Equivalents Found in Environmental and Human Samples. Regul Toxicol Pharmacol. 2020 Dec 17;:104842 Authors: Holland EB, Pessah IN Abstract Non-dioxin like polychlorinated biphenyls (NDL PCB) are recognized neurotoxicants with implications on altered neurodevelopment and neurodegeneration in exposed organisms. Two NDL PCB neurotoxic relative potency schemes have been developed for a single mechanism, namely activity toward the ryanodine receptor (RyR), or combined mechanisms including, but not limited to, alterations of RyR and dopaminergic pathways. We compared the applicability of the two neurotoxic equivalency (NEQ) schemes and applied each scheme to PCB mixtures found in environmental and human serum samples. A multiple mechanistic NEQ predicts higher exposure concentrations as compared to a scheme based on the RyR alone. Predictions based on PCB ortho categorization, versus homologue categorization, lead to a higher prediction of exposure concentrations. The application of the NEQ schemes to PCB concentration data suggests that PCBs found in fish from US lakes represents a considerable NEQ exposure to fish consuming individuals, that indoor air of schools contained high NEQ concentrations representing an exposure concern when inhaled by children, and that levels already detected in the serum of adults and children may contribute to neurotoxicity. With further validation and in v...
Source: Regulatory Toxicology and Pharmacology : RTP - Category: Toxicology Authors: Tags: Regul Toxicol Pharmacol Source Type: research