answrs 1 you should wear when you are in pollution, no side effects of not wearing it properly if you not Wear it properly it will not work properly. 2 don't do mask to tight or too lose 3 checking -you can check  mask by normal exhaling and inhaling, at the time of exhaling a mask will expand slightly and at the time of inhaling a mask will collapse slightly 4 mask is not reusable nor washable 5 it is difficult to tell which mask is most effective there is always one mask is better in one thing another is in second thing.

Hello there.  I can understand your concern.  Wearing mask in your case is necessary and normal surgical mask will not do anything. Better than that mask is a hankerchief. You should use N95 or higher mask. You can wear a mask for any amount of time. The best mask if price is not a constraint is a air filter mask. Do not buy chinese roadside mask as they are just made from padded bra. You cannot wash the mask. Different masks has a different life span. On an average N95 mask should come at a lifespan of 3 months on normal usage and on heavy usage, about 1.5 months. Air filter mask comes to about 6-8 months. At home you can use a air purifier or keep some air purifier plants whixh you can buy online or at a botanical garden near you. Best regards. Dr. Anil kumar jain. Bangalore.