FATE OF HEPTACHLOR AND ITS PRIMARY METABOLITE IN NANUMBA NORTH MUNICIPALITY, GHANA
The aim of this study was to assess the levels of contamination of heptachlor and heptachlor-epoxide in the Nanumba-North Municipality of the Northern Region of Ghana. Gas Chromatography equipped with electron capture detector (GC-ECD) was used to analyse the samples. In all, 148 samples were analysed, consisting ten (10) soil samples, 108 water samples and 30 food crop items. The study revealed the presence of heptachlor and heptachlor-epoxide at varying mean concentrations, with heptachlor-epoxide recording significant concentrations in the samples. The parent compound occupied 40% with a mean value of 0.008 ± 0.005 µg/L whilst heptachlor-epoxide occupied 60% with a mean value of 0.012 ± 0.008 µg/L. The trends of heptachlor and heptachlor-epoxide residues distribution in water samples from the various depths was of the order 30 cm and below > 15-30 cm >0-15 cm. The presence of heptachlor and heptachlor-epoxide in the water samples could be traced to wind drift or atmospheric transport of volatilized pesticides, direct overspray, direct spillage, pesticide misuse by farmers, run-off and leaching from application fields and surrounding areas during and after their applications. The concentrations of heptachlor and heptachlor-epoxide residues in the samples analysed were generally low and below the WHO (2017) MRLs. Therefore, the samples (soils, water and food crops) analysed in the study area at the moment will not pose any significant threat. Besides, heptachlor and heptachlor-epoxide detected showed significant differences at p < 0.05. However, just because there are low levels does not mean that consumers will not be exposed to its health risks. Since continuous availability can lead to bioaccumulation and biomagnification through the food chain. The findings therefore, emphasize the need for profound continuous environmental monitoring, enforcement of pesticide regulations, and the promotion of integrated pest management strategies to reduce reliance on persistent organochlorine pesticides and protect soil quality and public health in the Nanumba North Municipality.
Keywords: Heptachlor; heptachlor-epoxide; Nanumba-North Municipality; GC-ECD
