You may hear “experts” say that all soil has some amount of lead in it today, in the post-industrial revolution modern era. This is simply not true.
I have personally tested countless soil samples from around the country that were completely negative (non-detect / ND) for lead, so I know that lead-free soil is possible to achieve (or it already exists in natural spaces) today.
A few considerations:
- The more plant matter soil has, generally the less likely it is to have lead (or the more likely it is to have much lower levels of lead than soil that does not have high levels of plant matter.)
- Dustier/ gray/ loose fine soil is more likely to have higher levels of lead.
- Soil with rocks is nearly impossible to test with an XRF.
Soil levels and what they mean:
- 3,000 ppm. When my children were poisoned the soil levels in our yard were in excess of 3,000 ppm lead (from the contractor using an open flame torch on the exterior of home to remove paint).
- 400 ppm. The federal standard (the standard by which the EPA and HUD consider soil toxic) for soil that requires remediation is 400 ppm lead.
- 100 ppm. The scientific community (and specifically Dr. Howard Mielke, soils scientist/ researcher from Tulane) agree that even 100 ppm lead in soil is toxic and should be remediated/ should not be considered a safe place for children to play.
- 80 ppm. The State of California’s Los Angeles County has set 80 ppm lead in soil as the standard they would like to see for gardens (… so don’t garden in your soil if it is 80 ppm lead or higher.) They set this level as they determined it to be a level that is protective of children’s health.
- 40 ppm. Since I have seen so much lead-free soil and know that it is achievable, my recommendation is always that the soil in your yard should be below 40 ppm lead if you live in a city (or near older homes) and below 20 ppm if you are in a more natural/ less polluted area.
- 35 ppm. The soil in my yard (my “new” house [not where the kids were poisoned] in the city of Portland, Oregon) had test results that ranged from 35 ppm lead (near the street) to 165 ppm lead (along the drip line of the house) when we bought the house. As a result I did not allow my children to play in the dirt in the yard and found ways to cover and amend the soil, I also planted my vegetable garden in “raised beds” (lead-free wine barrels cut in half!) which I filled with new lead-free soil and compost.
Here is the post I wrote about remediation measures at my home, including some of the things we have done to keep the kids out of the soil and the soil away from the kids!
Post not yet edited by my husband, so please excuse the typos!
As always, please let me know if you have any questions!
Mother of Lead Poisoned Children
“Unexpected Lead Expert”