This paper aims to assess the concentration of some trace metals in the leaves of the invasive plant Ipomoea carnea Jacq. at El-Gharbiya and Kafr El-Sheikh Governorates, Egypt, in order to evaluate the suitability of its leaves as bio-monitoring of air pollution. Leaf samples were collected during the main growing season (summer) from four different habitats (road side, cultivated land, waste land and canal bank). Samples were analyzed for Cd, Cu, Mn, Ni, Pb, and Zn using Inductively Coupled Plasma Mass Spectrometry. Results indicated that the metallic elements in the leaves of I. carnea had the following sequence: Mn > Cu > Zn > Ni > Pb > Cd. The spatial variability of trace metals was significant only for Mn, Pb and Zn (at P < 0.05). Cultivated land and canal bank showed insignificant higher metal concentrations in its leaves compared with the road side and waste land habitats (except for Cd and Cu). The concentrations of Ni was positively correlated with the distance from the main motorway (r = 0.65, P < 0.05). All the measured trace metals had wide concentration range between sites. 50% of the sampled sites had high toxic concentration of Pb (from 7.2 to 17.8 ppm) more than the permissible limits recommended by WHO (> 10 ppm). The present results suggest the suitability of using I. carnea as a bio-monitor for trace metal pollution in the Nile Delta
Key words: Air pollutants, Bio-monitoring, Egypt, Invasive species, Nile Delta.
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