Lead in soils and plants: its relation to traffic volume and proximity to highways

TLDR: In this paper, soil and plants were sampled along heavily traveled highways and lead contents tend to increase with traffic volume and decrease with distance from the highway and the major effect of traffic was limited to the surface soil and to a narrow zone within 100 feet of the highway.

Abstract: Soils and plants sampled along heavily traveled highways show that lead contents tend to increase with traffic volume and decrease with distance from the highway. Much of the lead was present as a removable surface contamination on the plants. The major effect of traffic was limited to the surface soil and to a narrow zone within 100 feet of the highway. Plants grown in the field contained the most lead in the aerial portion and those grown in the greenhouse had the most lead in the roots. These studies indicate plants may obtain lead through both leaves and roots with little translocation within the plant. The fruiting and flowering parts of plants contained the smallest amounts of lead and showed little effect of changes in amounts of lead supplied. 19 references, 1 figure, 5 tables.