Pesticides are chemicals used by farmers to kill insects and organisms that destroy cultivated plants or reared animals. The use of pesticides by cocoa farmers in Ghana has increased over the years. Pests and diseases are some of the major factors that reduce cocoa yield in the country. Cocoa farmers regularly apply pesticides to boost productivity, but this can have adverse effects on the environment and lead to some health problems.
A recent study in some selected cocoa farming areas in the Dormaa West District, Brong Ahafo Region, has detected organophosphorus pesticide residues above recommended maximum residue levels (MRLs) in the soil and sources of drinking water.
The study, published in the Environmental Systems Research journal, used a high resolution Varian CP-3800 Gas Chromatograph equipped with pulse flame photometric detector (PFPD) to determine the pesticide residues in 32 soils and 64 drinking water samples from 16 cocoa farms.
The study found that soil samples from Nkrankwanta, one of the study sites, contained pesticide residues above the recommended US MRLs for agricultural soils. Water samples from two of the study sites, Diabaa and Kwakuanya, were also found to contain pesticide residues above the recommended WHO MRLs for drinking water.
High levels of pesticide residues in the soil can be harmful to soil organisms and cause plant toxicity. Crops, including cocoa beans, containing pesticide residues and contaminated drinking water can also cause health problems to consumers. Health problems associated with exposure to pesticides include low sperm count, birth defects and cancer.
Authors of the study were Benedicta Y. Fosu‑Mensah, Elvis D. Okoffo, and Christopher Gordon of the Institute for Environment and Sanitation Studies (IESS), University of Ghana; and Godfred Darko of the Department of Chemistry, KNUST, Kumasi, Ghana.
Digital reporter: Aaron Amankwaa, Editor