It has been awhile since I last posted at this blog. With the new cooler weather in Saigon, the cooler morning temperatures mean early morning PM 2.5 levels are returning. CNA Insider just posted a good video on air purifiers are whether they work or not. With Singapore’s temperatures relatively the same as in Saigon, I think they results will be useful to those living in Saigon. They also discuss if air purifiers can help remove covid-19 from the air. One thing to keep note on are the sources of particles in our homes that could affect our health.