I am sure if you inhaled burnt leaves the same amount some one sucked on a cigarette it wouldn’t be good for you as far as diesel trucks, they by law use an additive that gets rid of the obnoxious particulate smoke they once belched...
exposing one’s self to known bad things like smoke, heavy metals, radiation and many chemicals is like playing Yahtzee, smoke and play with chemicals you get two dice, add radiation your get three, pretty soon it enviable you will get dead by it, many times you have no control over your exposure, like the people who lived in times beach where they “ got rid of some dioxin”....I always wonder how many of those folks are still alive