Determination of Organochlorine Pesticide Residues and Trace Metal Concentration in Well and Stream Waters from Agricultural Farm Settlement in Ile-Oluji, Ondo State

Abstract

Pollutants is constantly introduced into the aquatic environment primarily due to amplified industrial activity, technical development, growing human population and mistreatment of natural resources, agriculture and domestic wastes run-off. Among these pollutants, Organochlorine Pesticides and some trace metals such as Lead (Pb)Mercury(Hg)and Cadmium (Cd) are found as one of the most hazardous because of their toxicity to organisms This study investigate the levels of organochlorine pesticide (OCP) residues and Trace Metal concentration in Well and Stream waters from Agricultural Farm Settlement in Ile-Oluji Ondo State. Ten (10) samples each of 1 Liter Well and Stream waters were collected randomly for trace metal analysis and another Ten (10) samples each of 2.5 Liter Well and Stream waters were collected for Organochlorine Pesticide analysis within the Farm Settlement and its vicinity. Quantitative determination of the OCPs was determined using Gas Chromatography-Mass Spectrometer after liquid-liquid extraction with (v/v) ethyl acetate/dichloromethane mixture and the Trace Metal was determined using Atomic Absorption Spectrophotometer. The results show that organochlorine pesticide residues were not detected in all the well water samples except for AKN where Heptachlor was detected in the concentration of 0.11 mg/L while all samples from the stream were contaminated with the Organochrorine pesticides at appreciably higher concentration than WHO standards. The results also shows that all the trace metals analyzed for are present except for some well samples where Lead concentration is below the detection limit. The mean concentration of some of the sampling sites were below the permissible limit for WHO while some are higher than the permissible limit.