TOXICOLOGICAL ASSESSMENT OF PESTICIDE RESIDUES IN LOCALLY GROWN RICE (Oryza sativa) FROM SOUTHEASTERN NIGERIA

This study investigated the levels of pesticide residues in locally grown rice (Oryza sativa) in South-East, Nigeria. Three varieties of rice were purchased from different locations (Abakiliki, Adani, and Omor rice mill), and were collected in 2 different batches (batch 1 and batch 2) and analysed. The pesticide residue levels were determined using gas chromatography coupled with an electron capture detector (GC/ECD). Organophosphate and Organochlorine pesticides were detected. The data obtained were compared to European standard limits. The samples from the different rice mills revealed the presence of pesticide residue levels (batch 1 and batch 2) above their European standards’ lower limits. Abakiliki (mass) had glyphosate (0.50 and 1.64), α-HCH (0.40 and 0.09) and HCB (0.02 and 0.25) in both batch 1 and 2, exceeding their EU standards of 0.1 ug/g, 0.01 ug/g, and 0.01ug/g respectively. The concentrations of glyphosate (0.70 and 0.10), g-chlordane (0.10 and 0.10), α-HCH (0.30 and 0.40), γ-HCH (0.03 and 0.10), HCB (0.20 and 0.30), P-P-DDD (0.30 and 0.19) and P-P-DDT (0.10 and 0.11) were above the EU standard of 0.1, 0.02, 0.01, 0.01, 0.01, 0.05 and 0.05ug/g respectively, in Adani rice (Farrow 44). Omor rice (Farrow 60) had concentrations of glyphosate (0.12 and 0.40), HCB (0.05 and 0.10), P-P-DDT (0.06 and 0.20), P-P-DDD (0.30 and 0.20) and P-P-DDE (0.01 and 0.10) that were above the EU standards of 0.1, 0.01, 0.05, 0.05, and 0.05ug/g. The results of this research reveal elevated pesticide levels in the locally processed rice when compared to European standards. This elevation, which may be a result of the varying (or inadequate) methods employed during processing, potentially poses a health risk to consumers.