Thailand has ordered more than 400 schools in Bangkok to close for the rest of week due to toxic smog.
The Thai capital is experiencing some of its worst air pollution with harmful levels of ultra-fine dust particles.
The Air Quality Index, or AQI, is used by cities to determine levels of air pollution.
AQI levels under 25 are considered safe to breather.
The reading in Bangkok on Wednesday evening was 175.
The government has tried a slew of measures to try to clear the air.
These include sending water-spraying drones and hosing down streets, but they have all had little impact.