OH!! So then tell me, what is the safe level of combustion engine exhaust!? We are ever increasingly smothering the entire northern hemisphere with ungodly amounts of chemicals, but we just don’t care because what,? Because we can’t see it? And then everyone seems to be BAFFLED that our kids turn out mentally unstable, homosexual, or genetically damaged. I’ll quit smoking when you stop driving combustion engine vehicles. How about THAT????