Quantitative analysis of toxic halogenated contaminants in Oluyoro stream of Nigeria

Abstract

Analysis of organic contaminants is reported for the Oluyoro stream located in the South-Western Nigeria. Using gas chromatography methods with flame ionization, electron capture and mass spectrometer detectors, alarming levels of organic pollutants including alkanes, alkenes, alcohols and alkyl halides were detected. Remarkably, toxic halogenated organic substances such as 4,4′-dichlorodiphenyltrichloroethane (4,4′-DDT), 4,4′-dichlorodiphenyldichloroethane (4,4′-DDD), beta-benzenehexachloride (beta-BHC), heptachlor epoxide, endrin aldehyde and endrin ketone are found to be at 15,820, 6,176, 1,155, 336, 24 and 13 times, respectively, more than the permitted levels of the United States Environmental Protection Agency (US-EPA). Furthermore, 4,4′-DDD, a probable human carcinogen, and methoxychlor are detected for the first time when compared to the last report published in 1992. Activities such as high influx of domestic and industrial wastes to the stream have drastically increased the concentrations of these halogenated contaminants. Results presented in this article provide important information for potential future effects of these contaminants on human health and the integrated environment in the region.