Distribution of polychlorinated biphenyl along the course of the Buffalo River, Eastern Cape Province, South Africa, and possible health risks

Authors

  • A Yahaya 1. SAMRC Microbial Water Quality Monitoring Center, University of Fort Hare, Alice, South Africa; 2. Department of Chemistry, University of Fort Hare, Alice 5700, South Africa
  • OA Adeniji 1. SAMRC Microbial Water Quality Monitoring Center, University of Fort Hare, Alice, South Africa; 2. Department of Chemistry, University of Fort Hare, Alice 5700, South Africa
  • OO Okoh 1. SAMRC Microbial Water Quality Monitoring Center, University of Fort Hare, Alice, South Africa; 2. Department of Chemistry, University of Fort Hare, Alice 5700, South Africa
  • SP Songca Department of Chemistry, University of Zululand, Private Bag X1001 Kwadlangezwa 3886, South Africa
  • AI Okoh 1. SAMRC Microbial Water Quality Monitoring Center, University of Fort Hare, Alice, South Africa; 2. Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, South Africa

DOI:

https://doi.org/10.4314/wsa.v44i4.09

Keywords:

organic pollutants, polychlorinated biphenyls, pollution, water, solvent extraction

Abstract

Humans and wildlife are vulnerable to the toxicity of semi-volatile and persistent organic pollutants such as polychlorinated biphenyls (PCBs). Neither the distribution of these pollutants nor their seasonal variation has ever been determined in the Buffalo River. Thus, the occurrence and concentration of 19 PCBs was assessed in King William’s Town (KWT), Izele (IZ), Zwelitsha (ZW), Maden (MD), Mdantsane (MSN) and Buffalo River estuary (BRE), all on the Buffalo River in the Eastern Cape Province of South Africa. Water samples were subjected to liquid-liquid extraction for PCBs, after which the compounds were separated and quantified on gas chromatography with electron capture detection. The PCBs differ in concentration from below detection limit (BDL) to 482 ng·L−1 in summer and BDL to 2 383 ng·L−1 in autumn. While the order of congeners increases during the summer from KWT > IZ > ZW > MD > MSN > BRE, the distribution in autumn followed the order BRE > IZ > ZW > KWT > MSN > MD. The total levels of PCBs at all the sites during summer were below the World Health Organization (WHO) permissible level of 500 ng·L−1 recommended for humans, but were exceeded at all the sampling sites in autumn except at MD. The evaluated risk with respect to cancer was lower than the acceptable threshold (10-6), whereas hazard quotients were slightly higher than the maximum threshold (of 1) stated by the United States Environmental Protection Agency (USEPA). The compounds are known to be toxic to humans and animals. The results appear to show that the exposure levels of the compounds were safe for humans and animals. Further studies are recommended in order to make a definitive conclusion.

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Published

2018-10-31

Issue

Section

Research paper

How to Cite

Distribution of polychlorinated biphenyl along the course of the Buffalo River, Eastern Cape Province, South Africa, and possible health risks. (2018). Water SA, 44(4 October). https://doi.org/10.4314/wsa.v44i4.09