I've read theories that part of the... let's call it "general cognitive decline" among certain populations in the US is due to widespread chronic lead poisoning. I don't know if any studies have ever been done but it kind of makes sense on the surface. If paint and fuel contained lead, it would have been nearly impossible to avoid exposure to it.
A few years back we heard a lot about lead in / around Flint, MI. But that isn't the only, nor perhaps the worst place. smh. Point of use filtration is key. A second key point is to work to remove the heavy metals one already has accumulated.
Edited: Some OF the cognitive decline you are seeing more recently is from long term inflammation caused by SARS-CoV-2 infection, and PASC "LongCovid". Cognitive decline can last for a year or more after infection, even mild cases. The average in the US is 4+ cases per person. Someone might take a hit to their cognitive function, start to make progress on recovery, and then gets a second infection which takes them down further.
Decreases in frequency-dependent intrinsic activity of the default mode network are associated with depression and cognition in patients with postacute sequelae of SARS-CoV-2 infection - https://pubmed.ncbi.nlm.nih.gov/39869209/
So according to wikipedia, the US banned lead paint in 1977, while Europe didn't implement such a ban until 2003 (though some EU countries had such laws before 2003). Additionally several countries are just now beginning to ban lead paints (Turkey, Ukraine, and Georgia didn't implement bans in after 2020).
Lead paint is fairly low on the scale, though obviously not great; leaded gasoline puts much more lead into the human body. Leaded gasoline was banned in both the US and EU in the 1990s.
It's a shame some of these elements are so toxic. I mean lead paint became popular for a reason, it's a great paint! If not for the toxicity.
I once met an old fighter pilot who let me play with his asbestos glove. I held burning coals in my hand! It was the most amazing material I've ever felt. Blew my mind, an almost perfect insulator. But of course we know asbestos to be awful stuff.
Makes me wonder if modern materials engineering could make asbestos safe? It's either not financially viable or the fear of asbestos is too great for society.
Most asbestos is safe, until you need to dispose of it. You could make a glove that is encased in another material so you get the insulation with no health hazard, but once it gets worn or thrown in a landfill it will be a problem.