Pesticide handling practices and residue levels in yam and cassava across Nasarawa South, Nigeria

The indiscriminate use of pesticides in agriculture poses serious health and environmental risks, especially in regions with weak regulatory enforcement. This study examines pesticide handling practices among farmers and assesses pesticide residues in yam (Dioscorea spp.) and cassava (Manihot esculenta) across Nasarawa South, Nigeria. Data were collected from 430 farmers using structured questionnaires and analysed with descriptive statistics and Chi-square tests. Additionally, yam and cassava samples were analyzed for pesticide residues using QuEChERS extraction and gas chromatography-mass spectrometry (GC-MS). Residue recovery ranged from 70% to 130%, confirming method reliability. Findings indicated poor adherence to safe storage and disposal practices, with household trash disposal being the most common method, posing environmental risks. Regional disparities were noted: Lafia exhibited better compliance in pesticide storage and disposal, while Awe lagged. Residue analysis revealed organochlorine, organophosphate, carbamate, and pyrethroid pesticides in food samples. Although no pesticide residues were detected in yam from Awe and cassava from Lafia, banned pesticides like Benzene Hexa Chloride (BHC) (0.000066 mg/kg) and Dichloro Diphenyl Trichloro Ethane (DDT) (0.00013 mg/kg) were found at varying concentrations in the cassava sample. However, mean residue levels remained below maximum residue limits. These findings underscore the urgent need for improved farmer education, stricter regulations, and sustainable pest management to mitigate health risks associated with pesticide exposure.