Assessment of Lindane and Atrazine Residues in Maize Produced in Ghana Using Gas Chromatography-Electron Capture Detector (GC-ECD) and Gas Chromatography-Mass Spectrometry (GC-MS)

Abstract

Maize is consumed by over 95% of the Ghanaian populace and the practice of using Atrazine and Lindane (an Organochlorine) pesticides in its production has raised concerns about potential adverse effects on human health and the environment. A field survey was conducted in this study to assess farmers’ knowledge of safe handling and use of these chemicals as well as toxicity awareness and symptoms among farmers and traders. Residues of these pesticides in maize samples as well as the potential health risk associated with exposure to them were also evaluated. Composite maize samples were collected for nine of ten regions in Ghana and analyzed. Data obtained from the field survey indicate that a large proportion of farmers are at risk of pesticide poisoning through occupational exposure. Over 80% of applicators do not apply safety precautions during pesticide mixing and application; resulting in considerable prevalence of pesticide related illnesses in the study area. Residues of Lindane and atrazine were below detection limits of 0.005 mg/kg and 0.010 mg/kg respectively; except in the Ashanti region where atrazine was 0.05 mg/kg which was within the EU-MRL of 0.1 mg/kg. However, minute concentrations of other Organochlorines (endrin—0.007 mg/kg; heptachlor—0.023 mg/kg; alpha-endosulfan—0.013 mg/kg) were found in maize samples from Brong Ahafo, eastern, central and upper west regions. Though endrin and alpha-endosulfan were below the EU-MRL of 0.01 mg/kg and 0.10 mg/kg respectively, heptachlor was slightly above the EU-MRL of 0.01 mg/kg. The estimated dose for all these pesticides however does not pose direct hazard to human health although present in the maize samples since the values were lower than toxic thresholds and reference doses. However, due to the unsafe application practices by applicators, there exists a potential risk for systemic and carcinogenic health effects by these chemicals in the study area.