Foliar transfer of dust and heavy metals on roadside plants in a subtropical environment

In this study, the contents of dust and associated heavy metals on roadside plants were investigated to assess their foliar transfer. The study was conducted at six different locations (four roadside and two industrial) near an industrial area in Bilaspur (Chhattisgarh), India. Six metals (Fe, Mn, Pb, Cu, Cr, and Cd) were examined in this study. The concentrations of heavy metals in foliar dust were found to be in the order of Fe > Mn > Pb > Cu > Cr > Cd. However, this relative order changed in the case of leaf concentrations to Fe > Mn > Cd > Cu > Pb > Cr. The metal concentrations in the dust and leaves can be attributed mainly to industrial and vehicular emissions. In contrast to other metals, Cd showed significant accumulation in the leaves compared to the respective dust samples. This study showed different patterns in the distributions of heavy metals between the dust deposited on the leaves and the metal accumulated in the leaves. These results suggest that the dust retention and heavy metal accumulation in native plant species should be explored in an attempt to manage these hazardous metallic elements.