Unhealthy levels of pollution are seen in Thailand this morning (Jan 21) as the country chokes from clouds of toxic smog.

Thick layers of air pollution blanketed the capital Bangkok and Chiang Mai in the north of the country.

Levels of the dangerous PM2.5 particles in the air soared past 100 micrograms per cubic metre - far higher than the safe amount of 50.

The pollution is caused by a combination of farmers burning waste crops to clear their fields in a process known as 'slash-and-burn' or fire-fallow cultivation as well as high numbers or fume-belching cars on the roads.

Low pressure, dry air and a lack of wind and rain mean that the pollutants are suspended in the atmosphere instead of being naturally dispersed.

Unhealthy levels of pollution are seen in Thailand this morning (Jan 21) as the country chokes from clouds of toxic smog.

Thick layers of air pollution blanketed the capital Bangkok and Chiang Mai in the north of the country.

Levels of the dangerous PM2.5 particles in the air soared past 100 micrograms per cubic metre - far higher than the safe amount of 50.

The pollution is caused by a combination of farmers burning waste crops to clear their fields in a process known as 'slash-and-burn' or fire-fallow cultivation as well as high numbers or fume-belching cars on the roads.

Low pressure, dry air and a lack of wind and rain mean that the pollutants are suspended in the atmosphere instead of being naturally dispersed.