The “action levels” of lead in food (fruits and vegetables, etc) are 10 parts per BILLION, and stuff less than that is considered acceptable, because otherwise freaking everything would test positive because food grows in dirt which contains minerals from rocks.
Another poster linked to this study that states [1]
Existing rates of lead absorption are about 30 times higher than inferred natural rates
It's not the case that all soil is contaminated with lead that then ends up in high levels in food. Top soil is composed mostly of decomposed plants. Plants only take up a small fraction of the lead in the soil. So the contamination of the top of the soil must reach some threshold. Due to leaded gasoline, there is widespread lead contamination in top soil, and I have read many parts of the world still use leaded gasoline in agriculture. Without human activity my understanding is that most soil samples would test very low or non detect and most food would as well. In some types of food (I know this is true of spices and to a lesser extent chocolate), much of the lead in food can come from processing phases after it is already harvested.
We certainly know it is the case that food produced by one producer varies dramatically in lead levels from another due to testing. Some of that may be attributed back to the soil, but it still goes to show that we could be testing soil levels and avoiding growing in lead contaminated soil.
Thank you for those links. For the nut study, they are studying finished products bought in the supermarket, so it is possible that some of the contamination may come from the processing (removing shells, etc) which is pointed out in the study itself.
I wouldn’t call it contamination if it’s literally just from natural soil and minerals sourced from fairly typical rocks.
I wasn’t claiming heightened lead exposure is good, just responding to those who seem shocked that we tolerate some low level of lead in foods.
Obviously leaded paint is dumb and we STILL, for some reason (well, I know the reason, but it’s not a good one imo), allow leaded aviation fuel. In fact, fully unleaded fuel was not allowed in a very large fraction of general aviation aircraft until recently because the FAA dragged their feet in approving lead free fuel mixtures for heritage general aviation aircraft (which is a large fraction of the general aviation fleet since lawsuits and the FAA have made newer aircraft just obscenely expensive), which is still very rare in small airports.
It is, ironically, the downstream effect of improper and over-regulation of general aviation.
The “action levels” of lead in food (fruits and vegetables, etc) are 10 parts per BILLION, and stuff less than that is considered acceptable, because otherwise freaking everything would test positive because food grows in dirt which contains minerals from rocks.
Lead has higher allowable levels in things like nuts, again because they are grown in the dirt and have a lot of minerals. I think peanuts and stuff have 100-900ppb lead. https://link.springer.com/content/pdf/10.1007/s12011-024-044...