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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 ...
The hydrosphere is the main reservoir. The immense volume of water in the oceans is still capable of dissolving a significant quantity of PCBs. [35] As the pressure of ocean water increases with depth, PCBs become heavier than water and sink to the deepest ocean trenches where they are concentrated. [36]
The inclusion of PCBs as a PBT may be attributed to their low water solubility, high stability, and semi-volatility facilitating their long range transport and accumulation in organisms. [5] The persistence of these compounds is due to the high resistance to oxidation, reduction, addition, elimination and electrophilic substitution. [ 6 ]
PCB-compounds, always containing low concentrations of dioxin-like PCBs and PCDFs, were synthesized for various technical purposes (see Polychlorinated biphenyls). They have entered the environment through accidents such as fires or leaks from transformers or heat exchangers, or from PCB-containing products in landfills or during incineration.
PCB contamination in humans may come from drinking the contaminated water, absorption through the skin, eating contaminated aquatic life, and/or inhaling volatilized PCBs. PCB contamination is especially dangerous for pregnant and nursing women. The contamination can reach the fetus and potentially cause birth defects.
PCB is suspected of having certain effects on liver and skin of humans. They are also suspected of causing cancer as well. EPA "estimates that 150 million pounds of PCBs are dispersed throughout the environment, including air and water supplies; an additional 290 million pounds are located in landfills in this country."
The certified humane label on your carton means that a third party has verified that the hens have continuous access to food, water, and free movement. "When this seal is combined with free-range ...
Conformal coating is a protective, breathable coating of thin polymeric film applied to printed circuit boards (PCBs). Conformal coatings are typically applied with 25–250 μm [ 1 ] thickness on electronic circuitry to protect against moisture and other substances.