Toxic smog caused by severe air pollution blanketed Bangkok, Thailand, for the second consecutive day.

The air quality reached dangerous levels of 200 on the IQ Air index in some parts of the Thai capital, with the safe levels of particles in the air being 50 micrograms per cubic metre.

Bangkok was the world’s fourth-most polluted city by 10 am, with residents complaining of headaches, sore eyes, coughs and a metallic taste in their mouths.

Particles that become stuck in people's lungs and airways can cause respiratory problems.

The country has been suffering from debilitating levels of toxic air pollution for several years, with the government seemingly unable to fix the problem.

Scientists believe is caused by a combination of still atmospheric conditions, a lack of rain and wind, agricultural burning and soaring numbers of cars and construction projects.

Smog is at its worst between January and March when farmers burn crops as it is combined with dry, stagnant weather and a winter low pressure system in which cold air is trapped closer to the ground by warm air above - preventing the pollution from being dispersed naturally.

The Thai government has been criticised for its handling of the country's air pollution crisis. Measures introduced in 2019 to reduce pollution included spraying water into the air to increase humidity without success.

''Unfortunately, this mitigation does not appear to be effective, since the volume of water is minuscule compared to actual rain,'' wrote data scientist engineer Worasom Kundhikanjana.