Abstract

Cooking oils belong to a large group of substances consumed on a daily basis. Heavy metals introduced during processing pose a threat to human health. Levels of Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni), and Copper (Cu) in four varieties of edible cooking oils (Vegetable, Palm, Coconut and Soy oils) collected in Apata and Bodija markets in Ibadan were digested and heavy metal levels were determined using AAS. The results were compared with WHO/FAO standards. A Health Risk Assessment study was carried out. The concentration of Pb, Cd, Ni and Cu were observed in the range of 4.45-9.15, 0.03-1.5, 0.73-4.78, 5.25-7.5, 0.005-0.025 mg/kg respectively. Heavy metal levels in all cooking oils were higher than WHO/FAO limit except in Cu. The concentrations (mg/L) of Ni, Pb, Cr, Cu and Cd (5.250-10.000, 1.325-9.150, 0.725-4.775, 0.005-0.025 and 0.025-1.875 respectively) were observed to be higher than JECFA recommended limits  except Cu. Estimated Dietary Intake (mg/kg/day) of  Cd, Pb and Ni (0.246-0.402, 1.384-2.152 and 2.277-2.525 mg/kg/day respectively) were higher than the Oral Reference Dose (RfD) (mg/kg/day) values (0.001, 0.004 and 0.020 mg/kg/day respectively) while Cr, Mn and Cu 0.281-1.091, 0.023-1.859 and 0.002-0.015 mg/kg/day respectively and were within the RfD values (1.500, 11.000 and 2.500 mg/kg/day respectively). Health Risk Index (HRI) values were less than 1 indicating that consumption of the cooking oils does not pose toxicological risk to the human health, however continuous intake may put consumer’s health at risk.


KEYWORDS: Atomic Absorption Spectrometry, Cooking oils, Health Risk Assessment, Estimated Dietary Intake.