We had a lot of construction work in the neighborhood, our house covered in fine dust particles each day. My kid got asthma in the same period, keeps asking when she can stop taking the medicines, and I say "I don't know" thinking "probably never". But maybe now the construction work is over, there is hope? (And if construction starts again, we know that it is better to move, because there is hope.)
In the UK's far-right media culture, Khan's ULEZ is painted as fringe extremism, not as a common sense public health measure.
There is a big difference between believing something is true, and demonstrating it is true and measuring the effect. One is a vibe. The other can drive policy.