Heavy metal concentrations in soils of five United States cities, 1972 urban soils monitoring program

Lead, mercury, cadmium, and arsenic levels were determined in soil samples from Des Moines, Iowa, Fitchburg, Massachusetts, Lake Charles, Louisiana, and Reading and Pittsburgh, Pennsylvania, as part of the 1972 Urban Soils Monitoring Program. Sampling sites within each Standard Metropolitan Statistical Area (SMSA) were defined as urban or suburban based on their position either within or outside the official city limits, respectively. In addition, each site was classified lawn or waste according to the maintenance it received. Except in Fitchburg, urban soils of each SMSA contained significantly higher mean concentrations of cadmium, lead, and mercury than did suburban soils. Mean urban soil concentrations in each SMSA except Des Moines and Reading, where urban levels were significantly higher. Generally, the metal concentrations in lawn and waste areas did not differ significantly. The results indicate a general contamination of these areas, probably as a result of fallout of airborne metal aerosols from industrial processes and/or fossil-fuel combustion.