120\130 is hardly good. It is in fact rated unhealthy for sensitive groups.
The WHO danger level for PM 2,5 is 25 units & the Thai government use 50 units.
Here in CM the PM 2,5 count is 56 units with the overall rating of 151. This is using the US AQI which is measured in real time so is much more accurate than the Chinese AQI which uses current & historical data to achieve a smoothing effect on the ratings.
Today has been a rather dynamic one with air movement changing the global ranking quite frequently. CM has dropped to 14th. BKK has risen to 6th, above any Chinese city.
I noticed that Homepro has stock of 3M brand PM 2,5 masks today. Looks like they have brought them in from Korea to meet local demand.