Lead in Soils in Paint Contaminated Residential Sites at San Antonio, Texas, and Baltimore, Maryland

摘要

Lead (Pb) is a toxic metal that can be harmful to humans when ingested or inhaled, particularly to children under the age of six. Lead poisoning can cause a number of adverse human health effects, but is particularly detrimental to the development ofchildren (USEPA, 2005). Lead induces a multitude of physiological, biochemical, and behavioral dysfunctions. The greater absorptive capacity of the gastrointestinal tracts of children puts them at much higher risk than the adults (ATSDR, 2000). Soil ingestion by hand-to-mouth activity (i.e., geophagia) is a major source of lead exposure to children. Primary sources of Pb pollution in soils include industrial activities, vehicular emissions, coal burning, refuse incineration, pesticide applications, andpaints applied to structural surfaces (Alloway and Ayres, 1997). Lead in paints is the principal source of human exposure to environmental Pb in the U.S. (ATSDR, 2000). Despite efforts made to reduce residential exposure to Pb (including setting a maximum allowable Pb content in paint of 0.06% in 1977), there exists a significant number of housing facilities in every city in the U.S. that were built prior to the implementation of that policy.