Doesn't this directly contradict the incidence of cancer vs. distance to industrial pollution maps? Like you're literally many times more likely to get cancer if you live near a source of industrial pollution compared to other people who live in your same city but don't live right next to a source of industrial pollution.
Think about it like this: the volume of a sphere increases proportional to the radius cubed. That means the further you get from a source of pollution, the density of that pollution falls off by a cubic of the distance. That's quite a sharp drop off. So small sources of pollution may pose some risk, but due to the small amount of particulate combined with how fast the pollution drops off means it's not so dangerous. Very large sources of pollution, however, may be dangerous for some distance.