Is lead toxicity from shooting guns a primary reason many Americans seem cognitively impaired ?

I have been thinking a lot since the election about what could explain the incredibly high numbers of Americans who seem incapable of critical thinking, or really any kind of high level rational thought or analysis.

Then I stumbled on this post https://old.reddit.com/r/guns/comments/16ires5/lead_exposure_from_shooting_is_a_much_more/

Which essentially explains that “Shooting lead bullets at firing ranges results in elevated BLLs at concentrations that are associated with a variety of adverse health outcome"

I looked at the pubmed abstract in that Reddit post and also this one https://pmc.ncbi.nlm.nih.gov/articles/PMC5289032/

Which states, among other things, “Workers exposed to lead often show impaired performance on neurobehavioral test involving attention, processing, speed, visuospatial abilities, working memory and motor function. It has also been suggested that lead can adversely affect general intellectual performance.”

Now, given that there are well in excess of 300 million guns in the United States, is it possible lead exposure at least partially explains how brain dead many Americans seem to be?

This is a genuine question not a troll and id love to read some evidence to the contrary if any is available