Dada A. O^1,, Makanjuola B. C¹, Adewumi M. O¹

Background Heavy metal contamination of vegetables compromises the quality and safety of vegetables consumed in Nigeria. Information on the level of heavy metal in commonly consumed vegetables is critical to promoting food safety, hence this study was carried out to determine the level of heavy metals in commonly consumed vegetables on sales in selected markets in Ibadan metropolis, Nigeria.Methodology The study design was laboratory based experimental study where five (5) different leafy vegetables namely; Celosia argentea (soko), Corchorus olitorius (ewedu), Amaranthus viridis (tete), Talinum triangulaire (water leaf) and Telfaria occidentalis (ugwu) commonly consumed were collected at different intervals in the various markets for a period of 12 weeks. Heavy metal concentration: (Lead (Pb), Cadmium (Cd), Zinc (Zn), Nickel (Ni) and Copper (Cu) were measured using Atomic Absorption Spectrophotometer. Data were analysed using descriptive statistics, one way ANOVA and comparison were made through t-test and line graphs. Results The results showed that lead (Pb) concentration in water leaf (1.70±2.07 mg/kg), also in Ugwu (0.43±0.35mg/kg) and copper concentration in water leaf (0.22±0.14 mg/kg) exceeded the WHO/FAO standard. However, there are higher concentration of cadmium, zinc, and nickel in some vegetables whereas others are within the safe limit. Mean heavy metal concentration was significantly higher in the evening samples than morning samples for all the heavy metals tested. (P<0.05). However, Mean Nickel (Ni) concentration was lower across all the vegetables assessed when compared with the standards. Conclusion Vegetables sold in the studied markets were laden with heavy metals of public health importance. Consistent monitoring and assessment of heavy metal contamination of vegetables sold in markets by regulatory authorities are recommended in the interest of the public and to promote food safety.

Heavy metals, vegetables, Market, Food safety