Lead and Soil
New US EPA guidance lowers the action level for lead in soil.
In the News
06-14-2024. The Conversation. What the EPA’s new standard for lead in soil could mean for households. "When the standard is adjusted down to the proposed level of 200 parts per million, 23.7% of households—nearly one in four—contain a lead hazard. [.....] Children can be exposed to lead by swallowing or inhaling soil while they are playing. Young children often put their hands in their mouths and may have dirt on their hands. Kids and pets also can track lead dust from soil indoors. And anyone who eats fruit or vegetables grown in contaminated soil can ingest lead. Early in 2024, the U.S. Environmental Protection Agency lowered the screening level for lead in residential soils from 400 parts per million—a standard that was more than 30 years old—to 200 parts per million. This more protective lower number reflects current understanding of soil as a significance source of lead exposure for children. EPA officials said that at homes exposed to lead from multiple sources, the agency will generally use a more conservative 100 parts per million screening level. This new level is not a cleanup standard; it’s a threshold at which the EPA will make site-specific decisions about how to protect people there. Actions may include providing information about soil lead, recommending ways to reduce exposure, or removing the leaded soil and replacing it with clean soil. The standard is designed to guide EPA assessments of residential soils around polluted sites under two federal laws. The Superfund law addresses hazardous wastes that were improperly created or disposed of before 1976, while the 1976 Resource Conservation and Recovery Act governs hazardous waste generation and disposal from that year forward. More than 4,000 sites across the nation are currently being cleaned up under those two laws. I study urban lead poisoning in children from soil and other sources, and I have worked with colleagues to analyze tens of thousands of soil samples collected from typical homes by research scientists and by citizens across the U.S. This work is ongoing, but our newly published findings show that under the new EPA standard, potentially harmful lead exposure from soil is far more widespread than many people—including public officials—realize. Reducing this risk will be a very long-term effort." Here's the link to the study
January 17, 2024. Press Release. Biden-Harris Administration Strengthens Safeguards to Protect Families and Children from Lead in Contaminated Soil at Residential Sites "Utilizing updated, best available science, EPA lowers screening levels for the first time in 30 years. [ ] EPA is lowering the screening level for lead in soil at residential properties from 400 parts per million (ppm) to 200 ppm. At residential properties with multiple sources of lead exposure, EPA will generally use 100 ppm as the screening level. Screening levels are not cleanup standards. While this update will help EPA site teams make site-specific cleanup decisions to protect nearby communities, EPA makes cleanup decisions specific to each site, using site-specific factors, including risk factors and community input that can vary from site to site. [ ] While the guidance goes into effect immediately, EPA welcomes feedback from the public that may be considered in any future updates to the guidance. Please submit written feedback on the guidance in the public docket (Docket ID: EPA-HQ-OLEM-2023-0664) for 60 days from January 17, 2024, to March 17, 2024.
What can property owners do to address high lead levels in soil?
There's no simple answer to remediating lead in soil.
The three "traditional" methods to deal with lead contaminated soil
Removal of contaminated soil to a licensed landfill. Expensive
Cover bare soil with 6" of mulch. Mulch coverings should be tested for lead content. Chipped wood mulch *could* have lead contamination.
Establish a solid covering of grass and keep bare spots reseeded through the year.
Anything that is a barrier between the contaminated soil and the children should work. The fact that your grandchildren have not picked up lead from the grassy area suggests that you have that space under control.
EPA recommends planting plants that can absorb lead, but CLASH is skeptical. Sunflowers, hemp, and tomatoes are all plants noted for being lead bioaccumulators. The problem is these plants cannot be burned, buried or composted without releasing the lead back into the soil. Here's a study,
Gardners can avoid contact with lead by building raised bed gardens. Use a plastic liner at the bottom of the bed then fill with clean soil to a level of 8" to a foot.
There's been some research on the use of Triple Superphosphate (TSP) Phosphate on soil to bind to lead and make the lead insoluble so that it can't be absorbed by the body.
Kitty litter? https://news.yahoo.com/common-cat-litter-ingredient-help-103010092.html. We never heard of this before! More research needed.
Where do toxic hazards in soil come from?
Abandoned automobiles can leak fluids on to the ground. Abandoned houses where there is chipping and peeling paint can spread lead dust to surrounding areas.
Exhaust from leaded gasoline (outlawed in the mid1980s) are still lurking in bare soil areas. Sites where cars, trucks, and buses sat idling are likely sources of lead pollution.
Highway and train overpasses are likely spots for lead contamination where structures are rusting and chipping.
Industrial emissions from plants which process metals can travel from smokestacks for miles in all directions. You won’t know if you have toxic elements until your soil is tested.
Demolished houses where there was lead paint were often buried on site. Over the years the lead in the buried debris can come to the surface where people walk and play.