Archive for the ‘ Soil Toxins ’ Category

marginy st. // existing and proposed

New Orleans // Lead Levels

Soil Toxins //  Lead (Pb) levels in soil

Soil intervention as a strategy for lead exposure prevention: The New Orleans lead-safe childcare playground project.

2010/11.    Howard W. Mielke, Tina P. Covington, Paul W. Mielke Jr., Fredericka J. Wolman, Eric T. Powell and Chris R. Gonzales


In the paper Soil intervention as a strategy for lead exposure prevention, documents the recent study using an in-situ experimentation procedure for remediating lead exposure at playground sites in New Orleans.  The strategy uses an upstream approach lessen health problems associated with Pb exposures by reducing Pb levels at the sites of primary exposure.   High levels of BPb (blood Pb) in children can damage cognitive development and cause behavioral problems. The southern end of St. Roch has median soil Pb of 900-1768 mg/kg which are some of the highest in the city of New Orleans.

The studies method is based on precedents.  As a result of hurricane Katrina new sediment was deposited on to the surface of some of the flooded areas.  The deposition of the Post-Katrina sediment decreased the soil Pb levels which correlated with a reduction of BPb in individuals living in those areas.  The playground remediation experiment mimics the natural phenomenon by depositing sediment from the Bonnet Carré spillway on top of a geotextile barrier which separated the polluted soil from the new soil.   All ten of the childcare areas experienced a dramatic reduction in Pb levels in the soils.

The paper makes a strong long-term argument for the societal and economic benefits of investing in similar remediation techniques.   The study projects a minor cost of $100 per child to improve the health of exterior playground areas to be within a Pb-safe margin.  The long term cost of dealing with lead exposure using a downstream strategy-dealing with the problem after it already exists- would be significantly more expensive and reduce the quality of life of residents.


1.      What affect do fresh water marshes have on removing Pb (lead) from soil?

2.      What other environmental toxins are being introduced with the imported soil from the Bonnet Carré spillway? What agricultural pollutants are present in the sediment?

3.      By essentially using a cap and cover technique to remediate the playgrounds Pb is still in the environment.  How much of the Pb would reach the groundwater?

4.      What are the long-term effects of burying the toxins?

5.     Could an ingredient be added to the toxic soils to help break down the Pb overtime?


WDSU article: Researcher Finds Elevated Lead Levels Across City