Plenty of ways to keep my immune system updated providing myself scratches and cuts while mountain biking / trail running, let alone eating snacks while on the

Plenty of ways to keep my immune system updated providing myself scratches and cuts while mountain biking / trail running, let alone eating snacks while on the trail with my hands absolutely not clean, or by simply breathing in a forest. But ingesting the black residue from exposure to diesel smoke while in transport is not for me, thanks. Feel free to train your immune system to dispatch tar.