Levels of organochlorine pesticide residues in fresh tomatoes from selected farming communities in Navrongo, Ghana

Abstract

The levels of organochlorine pesticide (OCP) residues in tomatoes sourced from three agricultural communities in Navrongo (Bonia, Korania, and Nangalkenia) were analyzed using gas chromatography. A comprehensive analysis revealed the presence of nineteen (19) distinct organochlorine pesticides, with a minimum of five different residues detected in each tomato sample. The OCPs were detected within a range of 0.04 to 15.90 μg/kg. Remarkably, beta-hexachlorocylohexane (β-HCH) exhibited the highest concentration (15.90 μg/kg), while both cis-chlordane and trans-heptachlor epoxide displayed the lowest concentration (0.04 μg/kg) in Korania. In the Nangalkenia community, gamma-hexachlorocylohexane (δ-HCH) demonstrated the highest concentration (10.21 μg/kg), while trans-chlordane and o,p'‑Dichlorodiphenyltrichloroethane (o, p-DDT) exhibited the lowest concentration (0.04 μg/kg). Furthermore, within the Bonia community, p, p-Dichlorodiphenyltrichloroethane (p, p-DDT) displayed the highest concentration (8.25 μg/kg), whereas o, p-DDT and trans-heptachlor epoxide exhibited the lowest concentration (0.13 μg/kg). Notably, the analysis indicated that two (2) of the organochlorine pesticides, specifically β-HCH and δ-HCH, surpassed the Maximum Residue Limits (MRLs) established by the United Kingdom/European Commission (UK/EC). The results of the questionnaire survey unveiled a substantial proportion of illiterate farmers (54%), which potentially plays a significant role in the farmers' misuse or indiscriminate use of pesticides. Additionally, both the questionnaire responses and field visits provided insight into the specific types of pesticides employed by the farmers. These include karate, lambda, carbofuran, mancozeb, ridomil, sunpyrifos, kocide, cypermethrin, and dimethoate.