Lead in Topsoil Linked to Cognitive Difficulties in 5 Year Old Boys

MedicalResearch.com Interview with:

Edson R. Severnini PhDAssistant Professor Of Economics And Public PolicyCarnegie Mellon University

Dr. Severnini

Edson R. Severnini PhD
Assistant Professor Of Economics And Public Policy
Carnegie Mellon University

MedicalResearch.com: What is the background for this study? What are the main findings? 

Response: Although lead has been banned from gasoline, paint, and other substances in the United States and many other countries around the world, the legacy of lead use is a critical environmental and public health issue. Surface soil contamination, in particular, has been long recognized as an important pathway of human lead exposure, and is now a worldwide health concern.

This study estimates the causal effects of exposure to lead in topsoil on cognitive ability among 5-year-old children. We draw on individual level data from the 2000 U.S. Census, and USGS data on lead in topsoil covering a broad set of counties across the United States.

We find that higher lead in topsoil increases considerably the probability of 5-year-old boys experiencing cognitive difficulties such as learning, remembering, concentrating, or making decisions. Living in counties with topsoil lead concentration above the national median roughly doubles the probability of 5-year-old boys having cognitive difficulties. This harmful effect does not seem to extend to 5-year-old girls, potentially due to the natural protection of estrogen.  Continue reading