EQA (Sep 2024)

DDT residue concentrations and distribution in fish from Sanyati and Munyati river, Zimbabwe

  • Wilson Mhlanga,
  • Reginald Dennis Gwisai

DOI
https://doi.org/10.6092/issn.2281-4485/18393
Journal volume & issue
Vol. 64
pp. 79 – 86

Abstract

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DDT residue concentrations and distribution were assessed in sixteen species of fish collected from the Sanyati River (B. lineomaculatus; H. vittatus; O. niloticus; O. mossambicus) and Munyati River (L. cylindricus; L. altivelis; M. longirostris; H. vittatus; T. rendalli; S. zambezensis; M. macrolepidotus; C. gariepinus; B. imberi; T. sparmanil; P. philander; M. salmoides) in Zimbabwe. The selected fish maybe economically important to the local people and have potential for consumption. DDT was used frequently in this region for tsetse control and malaria control. Eighteen fish samples were analysed for DDT, ∑DDE, and DDE/DDT ratio. Furthermore, they were identified/quantified using identified/quantified using Gas Chromatography (GC), (Hewlett Packard GC 5890 series 11 with electron capture detector) and standard methods through microwave-assisted extraction. The highest concentration of ∑DDT was 0.017 mg/kg in Sanyati River for B. lineomaculatus. While the highest concentration of ∑DDT was 1.0 mg/kg in Munyati River for T. sparmanii. The DDE/∑DDT ratio is still substantially high different species for both rivers indicating persistent and long – term exposure. The ∑DDT (ppb) appeared to decline from the 1980s up to the current study. The concentration of total DDT compounds varied markedly amongst the different fish species. The guideline value of 0.02 mg/kg fresh weight by WHO/FAO was almost reached and exceeded in some fish species (B. lineomaculatus for Sanyati River and T. sparmanii, L. cylindricus and L. altivelis for Munyati River), therefore implying potential harmful public health effects on humans. Since the pollution of the fish samples was an indication of contamination of the river, the quality of the water for public water supply maybe of concern because of the indication of application of banned pesticides and bioaccumulation. Therefore, further monitoring of residues in Sanyati and Munyati rivers is recommended.

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