Qi and clean air

WORLD Environment Day was on June 5, and it reminded me of the many days that it was impossible to practice qigong outdoors because of the haze. Actually whenever the air outdoors is dirty, the air indoors is also dirty, unless you have an effective air-filter or other air-cleansing methods.  

Doing physical exercises while breathing unclean air can be more damaging to health than the potential benefits of the exercises. Doing exercises would make us breathe more, hence, more of the pollutants, toxins and carcinogens which contaminate the air get into our lungs.