Lead levels in small mammals and selected invertebrates associated with highways of different traffic densities.

Lead levels in small mammals were studied in 6 areas -- 3 associated with highways of different traffic densities, and 3 control sites in forested areas. Lead levels were also studied in insects from 2 traffic areas and in earthworms from different distances from 2 traffic areas. Lead levels were low in insects ranging from 3.84 microng/g to 3.35 microng/g. Lead levels in earthworms were highest in those recovered closest to highways and from the area with the higher traffic volume. Lead levels in mammals generally was highest in mammals from areas of higher traffic densities. Higher levels of lead were found in shrews than in Peromyscus and Microtus.