Date-2: PM2.5 is 309 on July 16 in morning in Toroto

Today is the second day with wildfire smoke from NW of Ontario. The PM2.5 is 309ug/m3 whick is very higher. There is 500 in Michigan, US. 

I believe the face mask can not brock this smoke due to air leaking and no way to absorb the smell.

Please stay home and fins the best mask for smoke removal to wear.