Assessment of Heavy Metals in Beans (Vigna unguiculata) Obtained from Oja-Tuntun Market, Ile-Ife, Osun State, Nigeria

Abstract

Beans play a significant role in human diet especially in developing nations like Nigeria, the largest producer and consumer of beans in the world. To ensure food safety, heavy metal levels need to be monitored on regular basis to control human exposure through dietary intake. This study aimed at assessing the levels of heavy metals in some species of beans available in Ife market, Osun State, Nigeria. Samples of each species of beans were bought and analyzed for heavy metals using X-ray Fluorescence spectroscopy. Results showed that the concentration of heavy metals such as Cu was present at a level ranging from 0.131–0.205 ppm, and Zn was present at level ranging from 0.073–0.182 ppm. Cd was present at concentration < 0.039 ppm. Cu, Zn and Cd levels in natural beans sample were observably below maximum permissible limit set by WHO in Table 2. Therefore, it can be concluded that majority of these beans species were not contaminated with the studied heavy metals, hence pose no immediate health risk to human.