You hit the nail in the head with “extremely finely divided “. Lead particulate can and does get absorbed by blood as the particulate enters the stomach or lung via airborne lead particulate or lead trace in water. Just as with aluminium or zinc for example.
We might think lead due to its mass would sink and therefore wouldn’t enter water courses. However, when particulate is of significantly small size (through oxidising/eroding) the effect of mass/gravity is a weaker force the surface tension of the suspension liquid (water).
furhermore, the effects of lead could (it is thought and has been the subject of Nobel prize winning research) pass from one generation to another (two generations) through a process called epigenetiscs. So the consequences can be further reaching than we might assume
indeed lead has been banned in petrol and that had serious concerns. Similarly with lead pipe. But the concern isn’t simply a shooting red herring. Solder has no longer any lead in it (RoHS limit 0.1% by weight). Brass which typically contains <4% lead is highly likely to be banned in July 2021. Lead, used in steel to make it easier to process is also likely to be eliminated, same with leaded bronze. Lead has been removed from paint. None of these things are airborne or in soluble state and the steel, copper alloys, paint, plumbing and electronics industries are much more economically significant than shooting and the lobbyists in those industries also failed to prevent the legislation being enacted.
we might not like it, but it’s going to happen.
We can for sure say “people smoke”. It’s hardly the industry it once was either. Doctors used to recommend it. Now Smoking is akin to social leprocy. We learn, we adapt, we improve. BAT, Philip Morris’s and in fact the entire tobacco industry had to pay a $1/4 trillion in compensation over 25 year period (ten years to go) this along with rapidly declining sales despite growth markets in Africa, India, China, and Eastern Europe they will either adapt of go out of business and no one will care which except the investors and laggard smokers.
cars are coming under pressure. 2040 all electric if not sooner.
Even formula one has been embarrassed into claiming it will be carbon neutral by 2030
Aviation is also facing pressures with carbon offsetting, fuel efficiency (1% improvement = 800,000 gallons of Avgas saved per year). It’s not just social/environmental/legislative pressures either. It’s also economic.
Reform is a fact of human development. We reformed the constitution, voting, child labour laws, slavery, thalidomide, education, healthcare, governance, consumer rights, employment rights, banking (allegedly) and so it continues.
For sure there here are worse things going on much worse and I would advocate that the worst things are addressed first, but better to address something than do nothing. We really ought to take stock of how far we have come as a species and where we would have been had we not done anything to improve upon what we do.
So, I stick to my notion that lead will be banned and it’s better we accept that as a good thing on the whole for the many at a small and surmountable sacrifice by a few. Bit like Churchill Battle of Britain type rhetoric