Evaluation of Heavy Metals Level and Proximate Analysis of Common Fruits from Selected Markets in Lagos, Nigeria

Abstract

This study was carried out to determine the heavy metals concentration and proximate composition of five different fruits collected in triplicates from five different markets in five local government areas of Lagos state in Nigeria and extracted using Double Acid Extraction Method. Heavy metals concentration was performed using Atomic Absorption Spectrophotometer and proximate composition was determined by Association of Official Analytical Chemistry (AOAC) method. Results showed that the highest level of lead was found in carrot (0.18 ± 0.7) while pineapple (0.10 ± 0.0) had the lowest level of lead. The fruits in this study may have been polluted with lead through pollutants in irrigation water, farm soil or due to pollution from the highway traffic. Chromium, Cadmium and Copper was observed to be low in all the fruits analyzed, which is still within the safe limit set by FAO/WHO. Zinc had the highest concentration (3.99 ± 0.8) in water melon; proximate analysis indicated significant variability in the constituents contained in the fruits studied (moisture content, carbohydrate and crude fat in descending order). The highest moisture content was found in watermelon (91.3%) and the highest crude protein in carrot (1.138%). The concentrations of the toxic heavy metals are within the tolerable limits of some regulatory authorities. However, there is need for continuous monitoring of heavy metals and proximate analysis in fruits because, fruits are the main sources of food supplements for humans in many parts of the world and are considered as bio-indicators of environmental pollution.