Perspectives on airborne and soilborne contaminants and human health: the Earth scientist’s perspective

Category Geochemistry
Group GSI.IR
Location International Geological Congress,oslo 2008
Source www.۳۳igc.org
Holding Date 19 August 2008
 

Perspectives on airborne and soilborne contaminants and human health: the Earth scientist’s perspective

Mielke, Howard
Tulane University
, United States


The focus of this illustrated presentation is on lead (Pb) although other toxicants are also presented. Lead is an important and useful metal that has been mined extensively since Greek and Roman times. During the 20th century, the mined Pb was efficiently transferred to industrial-urban environments via at least two high production consumer products, Pb-based paint and vehicle fuel containing organic-Pb additives. Because the human population has undergone a transformation from rural to urban settlements and lifestyles, the quality of the urban environment has become a critical issue. Soils are an important part of the environment of all settlements. The question arose about urban contamination and one approach to answer this question was to conduct urban geochemical surveys. My first survey was on garden soils of Baltimore, Maryland in 1976. After completing the study, I moved to Minnesota, where I conducted surveys in several cities and towns. While Pb-based paint is often described as the principle culprit of soil contamination, Pb-based paint alone does not explain the observed pattern of soil Pb in urban settings. An alternate hypothesis we posed was that the Pb aerosols from organic-Pb in gasoline is more than co-equal with paint sources of Pb. Research on the interaction between airborne and soilborne contaminants from these two Pb sources makes it possible to understand the observed soil metal patterns and exposure response in both large and small U.S. cities. The geochemical pattern of urban soil contaminants provides a critical basis for understanding many human health and welfare issues. The Minnesota findings resulted in legislation that in 1986 cumulated in the U.S. ban on leaded gasoline. In 1988, after completing the urban research in Minnesota, I moved to Xavier University of Louisiana in New Orleans where I re-established a laboratory and began to conduct intensive urban soil contamination research, including replication and expansion of the urban soil surveys in towns and cities of Louisiana. Working with the health department and many colleagues, the outcome of the research was a deeper understanding of the sensitivity of children to airborne and soilborne contaminants and the essential need of society to prevent contamination and improve the geochemical quality of urban environments