We have attempted to differentiate the sources of trafficrelated
heavy metals in rice plants grown in the field along
the highway, and estimate the relative contribution of foliar
and root uptake. Our results revealed that Pb, Cd and Zn in
rice plants were partly from the foliar uptake, Cr and Cu
were mainly derived from the root uptake. Considerable
amount of foliar absorbed Pb and Cd were transported to
rice grain. While most foliar absorbed Zn were transported
to rice stems, the Zn contents in rice grains were mainly
from the root uptake. Foliar absorption and transportation
was a significant pathway for the accumulation of Pb and
Cd in rice grains. This suggests that mitigation strategies
should be applied to curtail both the foliar uptake and root
uptake of traffic-emitted heavy metals for rice cropping
along roadsides