As far as I can recall (and I'd have to check to be sure from many years back now), the surveys done on lead were all based around a certain area near Birmingham, after the area was swamped with a section of immigrants. Then they said it was effecting learning! But the people they asked the survey questions to, didn't speak English very well!
At the time many people questioned the validity of the reports being quoted (as I recall) but they just ploughed ahead anyway. Now we have unleaded that makes the atmosphere / ozone (which changes shape and size anyway) ... worse off. If any of it truly effects anything anyway !
I do see why the IAM are getting involved, as it relates to driver technique to 'drive for environment' ...
I do get the overall feeling that if one 'dare to disagree' to the environment propaganda machine, that you might feel immediately ostracized for being a 'traitor to the environment' .... but that requires that you 'believe' the whole green mass of issues. They introduce one, then the next, then the next, and before you know it the whole of life has changed around you ! Sound familiar?
It's another old sales technique too of 'create a problem to 'solve', after you have already created a way of solving it! Makes good money every time.
I do think being sensible and looking out for common sense solutions to try and be scientifically sensible as one possibly can be toward 'Mother Nature' is smart and sensible.
If I can place turbine into water and obtain 'free' electricity great, because it makes sense.
We started the modern industrial revolution mostly off water wheel power! Now we are in essence going back to it.
Designing cars which can be built to work with MNature than just abuse 'our world' is simply sensible.
Perhaps a car manufacturer and a Government have played their games for so long, that a straight talk is useless, so they convince and bargain their demands to produce an agreeable solution to them for business. But we do see some benefits and some laughable ideas, but many should have been developed anyway!
The racing car has helped develop standard vehicles too of course. That had little to do with 'environment' but just solving driving issues.
Would we go for sensible scientifically better products anyway ?
Perhaps some .....