The concentration (mg/kg dry weight) of Cd, Cr and Pb were determined
in onion leaves samples using the atomic absorption spectrometry. A
total of 16 onion leaves each were collected from both the study and
control sites for analysis. The heavy metals, Cd, Cr and Pb in onion
leaves of study sites were found in the range of 0.667 – 0.933,
3.870 – 7.870 and 5.870 – 7.537mg/kg respectively, while
the results of control sites showed values ranging from 0.583 –
0.700, 0.447 – 0.842 and 3.833 – 7.333mg/kg for Cd, Cr and
Pb respectively. The trend of abundance of heavy metals in both sites
followed the same sequence: Pb > Cr > Cd. The metals levels in
both sites are higher than WHO/EU recommended limits with exception of
Cd. The high levels of the metals suggest that effluent water irrigated
fields could be indicative of bio-accumulation of the metal