Soil Lead Accumulation Alongside a Newly Constructed Roadway

Abstract

Abstract Accumulation of lead (Pb) in soil along a new north‐south section of Interstate 95 at Beltsville, Md., was monitored annually between 1971 and 1977. The increase in Pb content of the top 10 cm of soil was closely correlated with cumulative leaded fuel‐burning traffic. Of the Pb accumulated between 8 and 50 m from the highway, between 95 and 98% was found within the 8‐ to 25‐m region. Within this zone, the accumulation rate was estimated to be 0.85 ± 0.16 µ g Pb/g soil per 10 6 leaded fuel‐burning vehicles at the 90% confidence level. Accumulation rates at 8 m from the highway were 1.04 ± 0.26 µ g Pb/g soil per 10 6 vehicles on the west or upwind side and 2.06 ± 0.73 at 8 m on the east or downwind side. Although the fraction of traffic burning leaded fuel decreased from an estimated 94% in 1971 to 73% in 1977, the decline was offset by the increased average daily traffic on the highway and no significant decrease in the rate of Pb accumulation was found through 1977.