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These chemicals or unchanged PCBs can be excreted in feces or may remain in a person's body for years, with half lives estimated at 10–15 years. [55] PCBs collect in body fat and milk fat. [56] PCBs biomagnify up the food web and are present in fish and overflow of contaminated aquifers. [57]
Pentachlorobenzene (PeCB), is a pesticide and unintentional byproduct. PeCB has also been used in PCB products, dyestuff carriers, as a fungicide, a flame retardant, and a chemical intermediate. This compound is moderately toxic to humans, whilst being highly toxic to aquatic organisms.
Bioremediation of PCBs is the use of microorganisms to degrade PCBs from contaminated sites, relying on multiple microorganisms' co-metabolism. Anaerobic microorganisms dechlorinate PCBs first, and other microorganisms that are capable of doing BH pathway can break down the dechlorinated PCBs to usable intermediates like acyl-CoA or carbon ...
Test results conducted in the fall showed the presence of PCBs, or polychlorinated biphenyls — toxic, man-made chemicals that were banned from being produced in the United States in 1979.
Ortho-PCBs may alter hormone regulation through disruption of the thyroid hormone transport by binding to transthyretin. [8] Coplanar PCBs are similar to dioxins and furans, both bind to the aryl hydrocarbon receptor (AhR) in organisms and may exert dioxin-like effects, in addition to the effects shared with non-coplanar PCBs.
A mixture of PCBs such as Aroclor may contain PCB compounds which are known estrogen agonists but are not classified as dioxin-like in terms of toxicity. Mutagenic effects have been established for some lower chlorinated chemicals such as 3-chlorodibenzofuran, which is neither persistent nor an AH receptor agonist. [23]
Co-signatories agree to outlaw nine of the dirty dozen chemicals, limit the use of DDT to malaria control, and curtail inadvertent production of dioxins and furans. Parties to the convention have agreed to a process by which persistent toxic compounds can be reviewed and added to the convention, if they meet certain criteria for persistence and ...
Polybrominated biphenyls (PBBs), also called brominated biphenyls or polybromobiphenyls, are a group of manufactured chemicals that consist of polyhalogenated derivatives of a biphenyl core. Their chlorine analogs are the PCBs.