Estimated Total Lead: Low, typical background levels
Hi, I recently received a soil test analysis and one of the things that stuck out was the...Estimated Total Lead : Low , typical background levels . Is this dangerous ? Should we be concerned ? What should we do ? Kind of nervous :-(..............................Jim
Jim, there are background levels of many different metals in soils, depending on what they formed from. They can also receive depositions from the air, that is why we removed Pb from gasoline, it was being deposited into our soils. That would raise it to dangerous levels.
Everything in the world is toxic at some level, you can kill yourself by drinking too much water. So your body can process so much Pb and not be affected, so some in your soil is not a problem. If it is low enough it won't have a large effect on you.
Here is a fact sheet from UMASS: https://soiltest.umass.edu/sites/soiltest.umass.edu/files/fact-sheets/pdf/SPTNL_5%20Soil%20Lead_0623...
It notes that normal levels of Pb are 15 to 40 ppm. This means for every million parts of soil you can have 40 parts Pb, so that's a very small amount.
Plants can take up Pb and you could breathe in the dust. You can see by the UMASS fact sheet that certain levels have specific restrictions on whether you should grow anything.So the EPA has determined that when soil levels are above 400 ppm, you can begin to accumulate enough Pb in your body to be have toxic effects.
Below 400 ppm, by liming your soil between 6.5 to 7 soil Pb becomes a solid mineral (like a rock) and plants can’t take it up. Washing your garden greens of any soil is a pretty good practice. When you get above 400 ppm it gets a lot more dangerous, and you are limited to what you can grow. Some plants take up metals easier than others.
So if your soil has background levels of Pb, it has been determined that this is safe and more than likely we have all taken in some our entire lives. If you still feel unsafe, get some fresh topsoil and put it over top of the garden. Or build a raised bed. If it is a yard, make sure you keep the grass in good shape and it will hold soil in place and limit dust from being blown off.
Also see the CDC website for more info: http://www.atsdr.cdc.gov/csem/csem.asp?csem=7&po=8