Assessment of Toxic Elements in Onion Farms in Northern Nigeria

This research has examined the levels of four toxic elements (lead, cadmium, manganese and iron) from four different locations of onion farms in Aliero metropolis of Kebbi State Nigeria in West Africa. The metals were analysed by atomic absorption spectrometry (AAS). The concentration of metals at the four sampling points, designated as A, B, C, D, follows the order: iron (D 65.588ppm > A 47.577ppm> B 7.927 > C 5.585), lead (A 2.321ppm > D 0.784ppm > C 0.517ppm > B 0.148ppm), manganese (A 1.552ppm > D 1.237ppm > C 1.070ppm > B 0.148ppm and cadmium B 0.008ppm > D 0.005ppm > C 0.004ppm > A 0.003ppm. Iron in all samples had higher concentration than the rest metals, while cadmium had the lowest concentration. However, the concentration of all the metals was below the WHO recommended limits.