Rest assured, you probably don't share the same oxygen as him. I think your average tree produces around 200-300 pounds of oxygen per year and a couple of large trees is enough to sustain a small family, so unless you live close by, i'm sure you're fine. Personally i think you're over-reacting or an angry person in general. I've witnessed absolute horrors from a mother being macheted infront of her child in Thailand to a guy putting a neighbour's cat in the microwave at a party, so you're definition of 'worst kind of human being' is a little displaced.