Health Risk Reduction of Organochlorine Pesticides (OCPs) Via Source Contamination Identification and Control in Water, Sediment and Fish in Ikot Ekpene River, Nigeria
Nsima Amos Akpan *
Department of Chemical Sciences, Ritman University, Nigeria.
Rosemary Boniface Udombeh
Department of Chemistry, University of Uyo, Nigeria.
Jonathan Okokon Ekanem
Department of Microbiology, Ritman University, Nigeria.
Mfon Bassey Ukpong
Department of Chemical Sciences, Ritman University, Nigeria.
Asuama Ignatius Ntukuyo
Department of Chemistry, Obong University, Obong Ntak, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The objective of the study was to determine the levels of organochlorine pesticides (OCPs) in the water, sediment and fish samples in Ikot Ekpene River, identify their sources of contamination and control for health risk reduction. Water, sediment and fish samples were collected from different sampling locations in wet and dry seasons and analysed using a Hewlett Packard 6890 series Gas Chromatography- Electron Capture Detection (GC-ECD). Concentration of the pesticides obtained varied across sampling locations and seasons. Principal Component Analyses (PCA) and factor loading plots for OCPs sources of contamination in water, sediment and fish showed both positive loadings in most cases and negative loadings in few, reflecting similarity and dissimilarity of sources of contamination respectively. PCA and factor loading plots in water samples during dry season, revealed that p,p’DDT (-.416) and endrine aldehyde (-.481) had same source of contamination. Alpha-BHC (.463) and heptachlor expoxide (.983) had similar source contamination while the source of p,p’DDE (-.077) contamination was different. In wet season, p’p’-DDE (.838), p’p’-DDT (.958) and Alpha-BHC (.744) were the only OCPs with similar source of contamination while the sources of others were different. In sediment samples, during dry season, heptachlor (.989) and beta-BHC (-.622) had different sources of contamination while the other OCPs had same source of contamination. In wet season, Delta-BHC (.867), Dieldrin (.858) and p’ p’-DDE (.865) had same source of contamination but different from sources of heptachlor (.867) and heptachlor-expoxide (.665). In fish during dry season, Alpha Chlordane (.983), Dieldrin (.990), Endosulfan 1 (.990) and Endosulfan 11(.990) had similar source of contamination while p’p’-DDE (-.932), p’p’-DDD (-.337) and Endrin-Ketone (-.340) had different source of contamination. In wet season, all the OCPs in fish had almost same source of contamination as they were in the same quadrant in the loading plot. With the identification of the sources of OCPs in the various matrix and routine monitoring to ensure total compliance to safe and regulated anthropogenic activities around the study area, levels of the OCPs in the samples and the corresponding health risk associated would be drastically reduced.
Keywords: Organochlorine pesticides, water, sediment and fish, Ikot Ekpene River, AAS, health eisk, statistical analysis