Just catching up with this, it was the scattalogical bit that grabbed my attention (or maybe the prospect of a replay of Python's "Every Sperm is Sacred"), but then I realised it's just some dumb argument along the lines that one airborne pollutant particle is just as dangerous as a whole cloud of them.
FFS. Even a cursory glance at the literature will tell you that there's a clearly demonstrated dose-response relationship between airborne particulates and morbidity/mortality.
Eg: "Each 1 μg/m3 increase in annual PM2·5 concentrations increased the absolute annual risk of death by 0·073% (95% CI 0·071–0·076)." (
https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(21)00204-7/fulltext)
What does that mean? A 1 μg/m3 concentration (maybe typical for a rural area) means there are several thousand of those 2.5 particles in each cubic metre of air. So in 10 years in that environment you'll be inhaling tens of millions of the little critters. Which nevertheless will be pretty unlikely to kill you. Living by an urban roadside on the other hand might mean breathing in 15-20 times that number, and your risk goes up proportionately.
Paracelsus, innit.