Assessment of systemic and carcinogenic health risks of persistent organochlorine pesticide residues in four fruit vegetables in south-western Nigeria

Abstract

PurposeThe study assessed the levels of organochlorine pesticides (OCPs) and their potential non-carcinogenic and carcinogenic health risks in four regularly consumed fruit vegetables.Design/methodology/approachThe OCPs’ residues were quantified using a gas chromatograph coupled with an electron capture detector (GC-ECD) and the dietary exposure of children, and adult consumers to the detected OCPs was evaluated using carcinogenic and systemic health risk estimations.FindingsAldrin, endrin, endrin aldehyde, a-endosulfan, β-endosulfan, endosulfan sulphate, heptachlor, heptachlor epoxide and dieldrin were detected in the four fruit vegetables. The predominant OCP residue in carrot, cucumber, tomatoes and watermelon was endosulfan sulphate with mean concentrations of 2.532 mg kg−1, 1.729 mg kg−1, 2.363 mg kg−1 and 1.154 mg kg−1, respectively. The residues levels in some of the fruit vegetables were higher than their respective maximum residue levels (MRLs) of 0.01–0.05 mg kg−1 set by the European Commission with concentrations above MRLs ranging between 25.5% and 100%. The systemic health risk estimations showed that the hazard index (HI) values for carrot (3.20), cucumber (9.25), tomatoes (50.21) and watermelon (16.76) were >1 for children consumers and the respective HI values of 2.87, 15.57 and 5.20 for adult consumers of cucumber, tomatoes and watermelon were >1 which implies potential systemic health risks. Four carcinogens (aldrin, dieldrin, heptachlor and heptachlor epoxide) had cancer risk index values greater than the acceptable risk of 1 in 1 million for both adult and children consumers.Originality/valueThe paper shows that despite the ban on the use of OCPs in Nigeria, they are still being used for agricultural production especially on some locally produced and regularly consumed fruit vegetables as reported in the present study. The non-existence of surveillance programmes on pesticide usage and the lack of proper monitoring of pesticide residues in food products including fruit and vegetables must have contributed to the levels of the detected OCP in the samples analysed. The current daily intake of OCP via contaminated vegetables may pose potential health risks to both the children and adult consumers of the fruit vegetables.