In New Orleans, Louisiana, more than 90 percent of housing structures were built prior to 1978 – the year lead was decreased in residential paint – making city residents vulnerable to lead-based paint hazards. In addition to deteriorating paint and the lead contaminated dust it generates, the lead dust from the use of leaded gasoline contributed significantly to elevated soil lead levels.
While leaded gasoline was phased out in the 1970s through the 1990s, the lead dust remains in soil, particularly within transit-heavy areas of the city. Researchers estimate that vehicles deposited more than 10,000 metric tons of lead dust in New Orleans soil between 1950 and 1985. In 2004, more than 40 percent of New Orleans soils exceeded the EPA’s cleanup standard for play areas.
Lead in soil can disproportionally impact children because they are more like to inhale and ingest dust and dirt.
Hurricanes Katrina and Rita
In August, 2005, storm surges from the Hurricanes flooded 80 percent of the homes of New Orleans and deposited massive quantities of low lead sediments into the city. The sediments created a natural barrier on top of the pre-existing high-lead soil establishing a cleaner, less hazardous landscape. This, combined with citywide cleanup and remediation efforts, reduced lead dust in homes and surrounding soil. Lead assessments conducted in Katrina’s immediate aftermath found a 46 percent reduction in median soil lead levels. And the declines continued. Before the storm, 15 of the city’s 46 census tract neighborhoods exceeded the EPA’s regulatory soil lead standards; by 2010, only 6 neighborhoods exceeded standards.
At the same time, there was a decrease in children’s BLL. Prior to the Hurricanes, 50 percent of New Orleans’s children had BLL’s equal or greater that the federal reference value of 5 µg/dL. Ten years after the Hurricanes, about 5 percent of the children’s BLL exceed that exposure value.
Lead-Safe Soil Emplacement Interventions
Inspired by the city’s unique natural experiment, researchers used a similar approach to clean up soil at 10 childcare centers in New Orleans, covering lead-contaminated surface soils with a water-permeable barrier and 6-inch layer of low-lead soil. Since 2005, nine of the 10 federal public housing projects were rebuilt using this process—landscaped with low lead soil to raise the elevation of the housing. This intervention was expanded to all New Orleans’s childcare center play areas and public playgrounds that tested high for lead.
These efforts, combined with the potential reduction of lead from fresh topsoil deposited by the storm surge during Hurricane Katrina, led to a decrease in the percentage of children with elevated BLLs in high-lead communities (mainly inner city) from 64 percent in 2005 to 19 percent by 2015. In short, household restoration and cleaning reduced lead-based paint hazards and washed-in sediments reduced soil lead. The remaining challenge is to reduce exposure in high lead communities by conducting more “soil emplacement interventions and continuing lead paint hazard reduction strategies.”
In August, 2017, the Health Impact Project, a collaboration between the Robert Wood Johnson Foundation (RWJF) and Pew Charitable Trusts released: Ten Policies to Prevent and Respond to Childhood Lead Exposure. The Trust for America’s Health (TFAH), National Center for Healthy Housing (NCHH), Urban Institute, Altarum Institute, Child Trends and many researchers and partners contributed to the report. TFAH and NCHH worked with Pew, RWJF and local advocates and officials to put together the above case study about lead poisoning and prevention initiatives.
The case study does not attempt to capture everything a location is doing on lead, but aims to highlight some of the important work.