Quite, phasing out leaded petrol at different times is the kind of "natural experiment" that can demonstrate the effects of lead reduction not poverty reduction

Quite, phasing out leaded petrol at different times is the kind of "natural experiment" that can demonstrate the effects of lead reduction not poverty reduction. This is not the same thing as "poverty drives increased pollution exposure, as a general rule" which is still true. Other things drive pollution exposure too, like general use of leaded petrol.