the world is dying of asthma?

Gawd this is a serious one and fairly technical- time to turn off perhaps.....
Everyone must be aware of the rising incidence of asthma in first world countries, and been told its due to our lifetsyles becoming 'too clean' . If you've got it, it reduces your lifespan to around 51 years old, so its serious enough. Everyone I know has a family member [not just a mate] who has bad asthma. You get to thinking.......
About 20-25 years ago, Uk and most first world countries were given auto cat cars, ie cars which cleaned their exhaust emissions. This was to remove a lot of greenhouse gasses NOx etc and which did its job very well indeed, and actually earnt UK PLC a load of dosh [and good luck to it !]
Then in about 1985 [ish], there was a check on roadside particulates to find out about PGM levels in the dust by the roadside.
PGM= Platinum group metals [the type found in car catalysts], ie had car catalysts been 'burnt' and evaporated/fouled/something. the results were frightening...... The levels in the initial report was someting like 100-1000 x the limit allowable ! Wow
This was the preliminary report. Before telling the world, they were asked to double check the findings [ by the way I dont know if it was UK HMG that had commssioned the study or a UK car cat manufacturer].The results on the check were that the results were correct, but that they had been reported incorrectly.
Background: Platinum is used in jewellery and is pretty and expensive and safe.
There is a form of platinum called 'soluble platinum' that is frankly horrible. It causes asthma in atomic amounts [if you are sensitised to it- ie 1 molecule/atom = asthma attack].
As far as I know there is no evidence that exhaust fumes + car cat= soluble platinum .
However Pt [platinum] is a very good catalyst [it can convert chemicals to other chemicals given the right circumstances]- which is why it's used in car exhausts. NOx= N2+O2, + co- co2 etc.
I wonder if small particles of Pt can act in the same way as soluble platinum? A small particle of Pt could react with NOx say , become soluble [very possible- its sort of how its made anyway] or just the small site area/volume could help it.
Anyway the bottom line is ..... are car catalysts responsible for quite a few deaths/rising to a HUGE amount of deaths in the future.
Readers please note : the supposition that small particles of atomic Pt causing soluble Pt or giving rise to the metal having similar properties to sol Pt is mine alone and as far as I know has no other research. the rest is true,