Yes, and no. There are varying levels of pollution everywhere we go. As toxins contaminate the air they replace and reduce the amount of available oxygen. The earth’s air used to contain as much as 50% oxygen. Today, it’s around 20%, and in some places around the world, like Tokyo and Beijing, it’s can be less than 10%. Science also tells us that stress (emotional or physical), lack of exercise, infections, medications, viruses, drugs and alcohol, highly processed foods and polluted water can reduce the amount of bioavailable oxygen in the blood stream.