Friendly reminder that leaded gasoline is still used today in airports all over the USA. If you live near an airport you are still affected by this in 2022.
Is there any conceivable way those chemicals could make their way into food? Should people use a watering can?
Is there any avoiding contaminants in food? Do we live in a post-contaminant society? Even our compost is contaminated.
the answer seems to be yes for most part of the world
https://slimemoldtimemold.com/2021/07/13/a-chemical-hunger-p...
My mental model is that lead metal and the above-mentioned salts are basically immobile in the soil: you can have all the lead sulfide or metallic lead you want in your soil without it leaching into the groundwater or contaminating the tomatoes you grow in it. And lead ions (in the form of the acetate, for example) are only mobile until they bump into one of the anions mentioned above, at which point they get locked up for geological periods of time. Organic lead compounds like tetraethyllead are a much scarier problem, but they also get broken down into ionic lead over a period of years.
Is that right? Am I misunderstanding the dynamics?
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
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?
This article references a couple studies as recently as 2020 which mention increased lead particles around airports.
https://www.nbcnews.com/business/business-news/leaded-gas-wa...
Link to actual EPA study:
https://countyairports.sccgov.org/sites/g/files/exjcpb686/fi...
This study mentions the lead levels in children living in proximity to airports:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3230438/
2021 Santa Clara study found lead levels in children near airports similar to Flint michigan:
https://news.sccgov.org/news-release/study-commissioned-coun...
Again, we are allowing leaded gas, which we know to be harmful, to be used in 2022, with demonstrable increases in lead levels especially for individuals living near airports.
100LL (aka avgas) has nowhere near the lead concentration that automotive fuels use, is used in much lower volume and with much less proximity to people than leaded automotive fuel.
If you are concerned about lead exposure test for lead in and around where you live and what you consume. That is the primary vector of lead exposure in 2022.
If you want to waste time with low effort comments direct them at the FAA because they are obstructing the current drop in unleaded replacement.
"On the basis of distance to airport coefficients, children living within 500 m, 1,000 m, or 1,500 m of an airport had average blood lead levels that were 4.4, 3.8, or 2.1% higher, respectively, than other children."
On the other hand, in 1971 lead averaged 2.5 g/gal. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6522252/ which has a nifty graph of leaded gas use and air lead concentrations with the neat note, "The increase in air lead concentration between 2000 and 2001 is likely due to changes at sites near stationary industrial sources. The decline in air lead concentrations between 2001 and 2002 is likely due to lower lead concentrations at sites in Herculaneum, Missouri.")
100LL has about 2.1 g/gal. (https://www.exxonmobil.com/en/aviation/products-and-services...)
Ah-hah: Herculaneum https://en.wikipedia.org/wiki/Herculaneum,_Missouri#Lead_pol...