Assessment of organochlorine pesticides (OCPs) contamination in relation to physico-chemical parameters in the Upper River Kuja Catchment, Kenya (East Africa)

Abstract

Concentrations of 17 organochlorine pesticides residues (alpha-HCH, beta-HCH, gamma-HCH, deltaHCH, Heptachlor, Aldrin, Endrin, Endosulfan I, Dieldrin, p,p’-DDT, Endosulfan II, p,p’-DDD, Endrin aldehyde, p,p’-DDE, Endosulfan sulfate, Heptachlor epoxide and Methoxychlor) were analysed in water and sediment from Upper River Kuja catchment, Kenya, between January-October 2015, using GasChromatography (GC) with (GC-ECD) equipment. Nutrient levels and water quality parameters: pH (7.57±0.354), secchi disk (0.05±0.019), dissolved oxygen (DO) (6.96±0.897), temperature (25.39±2.201), conductivity (62.03±23.123) and hardness (26.39±6.063) contributed to significant variations in organochlorine pesticide residue levels observed. Statistical significance differences (p<0.05) between water quality parameters in the sampling stations occurred. Pesticide concentrations ranged within BDL – 0.263µg