I don't think number 2 is necessarily true. Lifestyle and diet are much bigger influences. My grandparents lived in a town with coal as a heat source and for the trains moving through town. That's a lot more pollution than cars today. This is also the generation that walked places (for miles) and worked hard because they had nothing. They were a healthy weight and ate fairly healthy diets. They lived into their nineties and never went into a care facility.

I don't see how number 2 and 3 could be true together. One of the major theories on the increasing cancer rates is that people are living longer and this increases the chances of having cancer at some point. My grandfather had cancer, but didnt get it until he was 91 - then he beat it. The other theories tend to focus on environmental toxins not from car exhaust. Usually it's based on household chemicals and indoor air quality from items in the home.