Polychlorinated Biphenyls Contamination in Aquatic Organisms of Nigerian Inland Waters
Davies O.A., Anwuri P.A.
Polychlorinated biphenyls (PCBs) are mixtures of up to 209 individual chlorinated compounds called congeners with no natural sources in the aquatic organisms (Plants and Animals), only anthropogenic sources exist. This research reviewed the sources, effects, control, preventive, mitigation and remediation methods of PCBs as well as some cases studies of contamination of PCBs of Aquatic Lives in Nigerian Inland waters. Literatures of relevant and previous studies on Polychlorinated Biphenyls in Nigerian Inland waters within and outside Nigeria were reviewed. Anthropogenic sources are usually by industrial and shipping activities which may be direct or indirect. PCBs have major routes which are through accidental spills and leaks during the transport of the chemicals, from leaks or fires in transformers capacitors and other products containing PCBs. They tend to influence the patterns of survival, reproduction, growth, endocrine, hormonal function, enzyme activities and accumulation in representative aquatic organisms. Polychlorinated Biphenyls can also cause mortality or lethality in aquatic organisms when exceeded the normal body dosage. The Environmental Protection Agency standard for PCBs in the aquatic ecosystem is 0.0005 ppm. PCBs have been reported for some aquatic organisms in Nigerian Inland waters which are C. gariepinus inOgun River and Ona River. Mitigation and preventive methods are traditional, advanced technology and multi technology methods. Polychlorinated biphenyls are toxic, persistent and bio-accumulate in and biota as well as affect the physiology of biota and biological integrity of the aquatic environment. Government agencies should regulate the use of PCBs in the manufacture of various substances due to its harmful effects and industries should adhere to proper waste treatment before disposal into the aquatic environment.