On Wednesday, January 3rd, 2018, Saigon (Ho Chi Minh City), experienced one of its highest PM 2.5 AQI readings with a reading of 191 early this morning. The smog was noticeable. From Hoang Dieu street in District 4, you could not see the Phu My Bridge in District 8 which was just 5 kilometers away. So where is the PM 2.5 coming from? In short, since PM 2.5 tends … [Read more...] about Testing DIY Air Purifier on a bad air day in Saigon, Vietnam