The method of action is well supported and due to the inflammatory response. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3784920/
But, at this point it's clear you don't care about science when it conflicts with your gut feelings, a common failing.
I'm not calling into question the method of action, but I am saying that there is no evidence of outdoor air pollution having anywhere close to the same effect on premature death (via heart disease or otherwise) as smoking, nor would it even be remotely close to the other fictitious numbers you've mentioned.
Smoking on it's own causes ~6 million deaths per year and air pollution is linked to ~5.5 to 7 million deaths a year so they really are on the same scale. (And larger than my example 20% vs 30%.)
Yes, only a subset of the population smoke so the direct impact is higher. However, some areas also have vastly higher levels of air pollution.
Now, if you have some actual evidence then sure feel free to share, but I am just not hearing it.
Instead of merely reading the conclusions of these studies, I'd encourage you to look at the underlying data with a healthy dose of skepticism. Only then will you start to see all the holes in the research.
You even have edge cases like parking lot attendants / toll collectors who have vastly increased disease risks.