Analysis of Some Pesticide Residues in Tomatoes in Ghana

ABSTRACT

Pesticide residues, both natural and synthetic, can be found in most of the things we eat, for example, fruits, vegetables, bread, meat, poultry, fish, and the processed foods made from them. Some of this pesticide contamination is legal, but does this mean it is safe? Much of it is illegal, with residues found in excess of regulatory safe levels. Identifying and determining the level of trace contaminants in our food and environment is critical in protecting and improving human health and the environment. This study evaluates the residue levels of select pesticides used on tomato crops in Ghana that are likely to have accumulated in the tomatoes during application. The results obtained confirm that pesticide residues were indeed present in the tomatoes and further analysis quantified the amount present. Analysis of some organochlorine and organophosphorus residue levels in the fruits indicated that chlorpyrifos, which is an active ingredient of pesticides registered in Ghana under the trade name dursban 4E or terminus 480 EC for use on vegetables, has the greatest residue level of 10.76 mg/kg. The lowest residue level observed was that of pirimiphos-methyl with 0.03 mg/kg. Human health risk assessment was performed on the results obtained from the analysis using Human Health Evaluation computerized software-RISC 4.02. The risk assessment showed cancer risk for adults and children due to the presence of endosulfan and chlopyrifos. Endosulfan is not registered in Ghana as a pesticide for use on vegetables, therefore the detection of endosulfan in several samples indicates misuse of agrochemicals among Ghanaian farmers.

Key Words:

• pirimiphos-methyl
• fenitrothion
• lambda-cyhalothrin
• chlorpyrifos
• folpet
• cypermethrin
• endosulfan

ACKNOWLEDGMENTS

The authors express their profound gratitude to Mr. Samuel Frimpong (Asst. Scientific Officer at the Pesticide Residue Laboratory of the Ghana Standards Board) for his assistance in carrying out the various analyses. Also we thank the government of Ghana for financial assistance.