air pollution effect in the digestive system

all in our body is control in need to oxygen 

that mean digestive system are affect in pollution becouse all in our digestive system are control in oxygen if oxygen are neat in our body then our digestive system are disorder.
oxygen is helps to digestion food .and most important oxygen are helps to exist  in living organism.
also digestion are important in living bean becouse cell are living with helps to oxygen.

air is going in our body if that are pure then not harmful effect in we all but if that air are pollute then that are harmful effect of human being.