Lead dust contaminated U.S.A. communities: comparison of Louisiana and Minnesota

Abstract

Lead from gasoline has played a major role in the geochemical distribution patterns of Pb within U.S. cities. Since 1950, ~75,000 and 89,000 t of Pb were consumed as a gasoline additive in Louisiana and Minnesota, respectively. Previously, a survey was conducted in five cities in Minnesota that showed a relation between soil Pb and city size. New empirical data are presented on the geochemical pattern of Pb in soils within six cities of Louisiana. Soils were collected from within 1 m of the sides (foundations) of residences, within 1 m of the street, and from open spaces (yards or parks) within each city. The data show that soil Pb is a function of city size and that the inner city of the largest town had the highest Pb accumulation. Remarkable statistical differences (exact p -values as low as 10 −80 ) between street-side soils of central New Orleans and adjacent communities, and other cities of Louisiana, were demonstrated. The Louisiana results are similar to those of five cities in Minnesota. The median of foundation and street-side soil samples within inner city communities of New Orleans and Minneapolis were >840 and 265 ppm Pb, respectively, whereas the median soil Pb for foundations and street-sides of the small towns of Natchitoches, Louisiana, and Rochester, Minnesota, were <50 and 58 ppm Pb, respectively.