Risk Assessment of Residual Pesticides of Phaseolus vulgaris L. Consumed in Port Harcourt, Rivers State, Nigeria

Pesticides are important and necessary in reducing the loss caused by insect infestation on grains. However, its toxicity and persistence in the environment is of health concern. Beans (Phaseolus vulgaris L.) preserved with insecticide are considered to be good for consumption if its content of insecticide is not higher than the maximum residue limits (MRLs). The aim of this research was to quantify the residue of pesticide in four beans samples and determine the health risk associated with consuming these foods by residents of Port Harcourt, Rivers State, Nigeria. Pesticides content of beans samples were analyzed using Gas Chromatography (GC). The results of the study showed the presence of 17 different pesticide residues in all samples of beans. 2,4-Dichlorophenoxyacetic acid (2,4-D) and 2,2-dichlorovinyl dimethyl phosphate (DDVP) were detected in all samples of beans and at levels above European Union’s (EU's) MRL except in iron beans samples. Glyphosate was detected in all the samples at concentration above EU’s MRL. However, pesticides in Raw iron beans such as carbofuran (0.43±0.03 mg/kg), Endosulphan (0.18±0.01 mg/kg), HCB (0.62±0.10 mg/kg) Profenos (0.55±0.04 mg/kg) and t-nonachlor (0.32±0.00 mg/kg) decreased significantly to 0.23±0.10 mg/kg, 0.09±0.01 mg/kg, 0.31±0.01 mg/kg, 0.38±0.01 mg/kg, and 0.22±0.00 mg/kg respectively in Parboiled iron beans. This indicates reduced Health Risk Index (HRI) to pesticides of parboiled beans samples. Similar results were also recorded in other raw and parboiled beans varieties studied. This calls for the attention of regulatory agencies in foods and food products to effectively monitor the use and application of pesticides on foodstuff and also encourage parboiling before cooking to eat.