Pollution Research Paper

EFFECT OF ORGANOCHLORINE PESTICIDES USAGE ON WATER QUALITY OF TANO RIVER IN THE ASUNAFO SOUTH DISTRICT OF BRONG AHAFO REGION OF GHANA

E.A. AGYAPONG , J.A. LUGUSHIE , B. FEI-BAFFOE AND A. ATABILA

Abstract

The use of pesticides in farming to control pests and maximize yields has increased over the years in Ghana. Overuse and misapplication of these chemicals can have negative environmental impacts, especially on water resources. This study investigated pesticides usage and their effects on the water quality of the Tano river. Water samples were collected from two farming communities in the Brong-Ahafo Region of Ghana for physico-chemical and pesticide residue analyses. The levels of pesticide residues were determined by gas chromatography with an electron capture detector. The results showed measurable levels of pesticde residues in most of the samples. These included HCH isomers, aldrin, deldrin, endrin, chlordane isomers, DDT and its metabolites, and heptaclor isomers. The results further showed that most of the residues occurred at levels that were within the WHO guideline values for drinking water. However, aldrin, dieldrin, endrin, heptachlor and cis-heptachlor epoxide with highest mean concentrations of 0.474, 0.147, 0.842, 0.814 and 0.658 µg/L, respectively, exceeded the limits. The highly measurable levels of these residues are worrying and could pose a threat to human and aquatic life within the watershed.