Lead in soil gets stirred up by wind, rain, humans and animals into the air all day long.
Of particular risk as far as food contamination is concerned are leafy vegetables and shrubby fruits that grow near the ground (surface contamination, eventually binding to the food - not internal uptake necessarily).
There are studies measuring these effects, you don’t have to take my word for it.
This CDC page seems to say that swallowing or breathing lead-contaminated soil is a problem (most of the minerals I mentioned won't withstand strong solutions of hydrochloric acid, such as stomach acid) but it doesn't even suggest that lead-contaminated soil is a potential source of groundwater contamination or contamination of plants grown in it. Nor does it suggest that soil being stirred up by wind and rain is a significant danger, though presumably a sufficiently strong windstorm would be.
It links an EPA page https://www.epa.gov/sites/default/files/2020-10/documents/le... which does talk about "eating fruits or vegetables grown in contaminated soil". More specifically it recommends not growing root crops such as potatoes in soil with over 100 ppm lead, low-growing leafy vegetables in soil with over 400 ppm lead, or fruits and vegetables in soil with over 1000 ppm lead. It still doesn't mention anything about groundwater.
Unfortunately it doesn't cite any of the studies so we can find out what levels of lead contamination occur in crops grown in contaminated soil or to what degree they're dependent on lead not being locked up in the mobile forms I described (can potato roots digest galena?), nor to what degree lead-compound dust on poorly washed lettuce results in human lead poisoning.
Since the CDC didn't link any, which studies would you most recommend reading?
Of particular risk as far as food contamination is concerned are leafy vegetables and shrubby fruits that grow near the ground (surface contamination, eventually binding to the food - not internal uptake necessarily).
There are studies measuring these effects, you don’t have to take my word for it.
Here is what the CDC has to say https://www.cdc.gov/nceh/lead/prevention/sources/soil.htm