26-year changes in Amounts of Heavy Metals and Base Cations in Organic Horizons of Mid-Atlantic Region Forest Soils.

We repeated a study done in 1978-79 to determine if the amount of lead, copper, zinc, calcium, and potassium had changed in 26 years in the organic horizons (forest floor) of the Mid-Atlantic Region of the U.S. We resampled the forest floor at 29 of the 34 original sites, and analyzed the samples on an ICP.

The data indicate that the amount of lead at these sites decreased 52% due to the cessation of leaded gasoline, zinc and copper decreased near the point sources where they had been emitted, calcium amounts decreased 20%, and increases in potassium were due to increases in forest floor mass.