Notes. Effect of decreased use of lead in gasoline on the soil of a highway

Abstract

So that the effect on lead concentration in highway soils of the mandatory use of unleaded gasoline in new automobiles could be assessed, lead concentrations in soils along U.S. Interstate 20 in northeast Louisiana were determined in 1973, 1974, and 1979. These concentrations increased from 1973 to 1974 but decreased from 1973 to 1979. Lead in the soil moved slowly in the direction of surface water flow. Lead concentrations decreased with depth to 300 mm but then increased. The mandatory use of unleaded gasoline has decreased the lead concentrations in soils near highways.