This is because food cannot be heavily processed without some heavy metals leeching in, according to a food safety guy who is a long time friend.
It is completely mind boggling we let that happen.
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...
Existing rates of lead absorption are about 30 times higher than inferred natural rates
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.
[1] https://sci-hub.se/https://pubmed.ncbi.nlm.nih.gov/14334042/
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.
Do you think it should be 0? 0.0000 ppb? No detectable lead whatsoever? What do you do if detection technology improves and the minimum detectable level decreases?
Even if you go live totally off the grid with your child and grow your own vegetables in your backyard with completely natural ingredients, you will still end up with some level of lead - which is a natural ingredient itself, after all.
At some point, you have to set a threshold and say that any lead below this level is not worth the cost of removing it or avoiding it. Would you pay 10x more for baby food at a 1 ppb level instead of 10 ppb? Do you think that would produce a net benefit for society?
People in this thread https://news.ycombinator.com/item?id=43631251 have been arguing that these people must have been some top class elite, and I totally get it. They are too good looking. But, that's how it was. The typical of the past would be above celebrity looks today. A lot of curent idols look stunted in comparison.
Existing rates of lead absorption are about 30 times higher than inferred natural rates
In fact, to fully avoid lead, you’d basically have to carefully grow food hydroponically. Certified Organic mineral fertilizers like basalt rock dust (which provide calcium, phosphorus, and potassium, etc) would obviously not be okay if you wanted to eliminate all lead, as basalt contains 7.5ppm lead, comparable to the average in the Earth’s crust.
The problem with our standards for baby food isn't necessarily that they are too high. The problem is that there is little enforcement. You have know way of knowing you will be getting 10ppb or be the unlucky one getting the large dosages that eventually got reported to the CDC. For much of the rest of the food supply the standards do allow for too much lead.
Our ability to detect lead only gets better and better with new technologies. Whereas a few decades ago we could detect 1 part in 1 million (ppm) we can now routinely detect down to 1 part per 1 trillion (ppt), that's 1 million more sensitive analysis.
To give a sense that's a 1 microgram in 1,000 tons of material.
As a result, you can't set the level at "no lead" because that's an impossible level to achieve.
Right now the US sets it at 10 parts per billion. So in a normal jar of baby food - approximately 100 grams - that's less than 0.1 microgram of lead.
Lead naturally occurs in soil at levels 15-40 parts per million or 1,000 times higher. Growing your own veggies in soil untouched by man is going to risk higher levels than allowed in baby food.