Assessment of Dietary Exposure to Organochlorine Insecticide in Cabbage (Brassica oleracea) from Selected Markets and Stores in South-western Nigeria

Abstract

Cabbage (Brassica oleracea), a ready-to-eat vegetable obtained from open markets and stores was analysed for its organochlorine insecticide (OCI) contamination and potential health risks associated with its regular consumption. The OCI residue levels in the extract from the vegetable were determined using a Gas Chromatograph coupled with Electron Capture Detector (GC-ECD). Health risk estimates were analysed using Estimated Average Daily Intake (EADI) and Hazard Index (HI) for children (16.7 kg) and adults (60 kg) weight categories. The residue analysis showed that the predominant OCI detected in cabbage samples from stores were dieldrin (6.607 ± 4.232 mg kg^-1), endrin aldehyde (3.774 ± 0.363 mg kg^-1) and methoxychlor (1.404 ± 0.519 mg kg^-1), while endrin aldehyde (4.098 ± 0.770 mg kg^-1), aldrin (1.583 ± 1.024 mg kg^-1) and methoxychlor (1.543 ± 0.460 mg kg^-1) recorded the highest concentrations in samples from open markets. However, there was no significant difference in residues detected in cabbage from stores and open markets at p > 0.05. The percentage of detected residues above the United Kingdom/European Commission Maximum Residue Limits (MRL) ranged from 13 to 100%. The analysis of health risk estimates revealed that aldrin, dieldrin, endrin aldehyde and heptachlor concentrations were above the reference dose for children, while the quantities of aldrin, dieldrin and endrin aldehyde exceeded the reference dose for adult category. The results revealed that the detected residues exceeded acceptable standard and may present potential systemic risk to the vegetable consumers. Thus, a regular training of farmers on pesticide safety practices, especially on the need to adhere to recommended pre-harvest intervals and routine monitoring of pesticide residues in cabbage and other salad vegetables by regulatory agencies are recommended.