A woman wearing a face mask walks in heavy smog in Harbin, northeast China's Heilongjiang province, on October 21, 2013. Choking clouds of pollution blanketed Harbin, a Chinese city famed for its annual ice festival on October 21, reports said, cutting visibility to 10 metres (33 feet) and underscoring the nation's environmental challenges.   CHINA OUT     AFP PHOTO        (Photo credit should read STR/AFP/Getty Images)
How deadly is air pollution?
01:08 - Source: CNN
CNN  — 

Parts of Asia are chocking under a thick layer of smog, leading at least one country to experiment in extreme forms of weather modification in an attempt to clear the toxic brown skies.

Thailand, South Korea, China, India and Hong Kong are all facing unhealthy and even hazardous levels of pollution as weather patterns, coal heating and emissions contribute to the annual crisis.

According to the World Health Organization (WHO), nine out of every 10 people on the planet breathe air containing a high level of pollutants, with the worst affected regions being Africa and Asia.

Thailand

Water cannons were being used on January 14, 2019 to clean the air and streets in Bangkok.

Authorities in the Thai capital Bangkok are expected to deploy planes with special rainmaking capabilities – a technique known as cloud seeding – on Tuesday, with the aim of easing pollution in some parts of the city, according to the Bangkok Post.

The concept involves injecting clouds with small amounts of inert chemicals, such as silver iodide, in order to increase rainfall. In recent years, it has been used by nations that suffer from severe seasonal pollution levels, including China.

Several areas of Bangkok, a sprawling and heavily congested city of 8 million, are seeing high levels of PM2.5 pollution particles – microscopic particles smaller than 2.5 micrometers in diameter which are considered particularly harmful because they are small enough to lodge deep into the lungs and pass into other organs.

In recent days, the levels have been hovering around 150-200 microgrammes per cubic meter, which is considered unhealthy on the Air Quality Index (AQI), according to CNN meteorologists. The World Health Organization considers AQI levels under 25 to be acceptable for humans to breathe regularly.

Firefighters Monday blasted water from high-pressure cannons around Bangkok’s City Hall and other areas, as part of short term efforts to ease the hazardous smog, the Post reported. There is debate as to whether water is effective in washing away the finer and more dangerous PM2.5 particles.

South Korea

For five consecutive days, high levels of fine dust have blanketed parts of South Korea, according to local media. Over the past 48 hours, the cloud of fine dust has reached very unhealthy levels of between AQI 150-225, CNN meteorologists said.

Local governments in ten cities have enacted emergency measures, such as limited vehicles on the road and reducing emissions output at factories, while people in Seoul covered their faces with masks and avoided going outside unless necessary.

“The air is so murky and my throat hurts that I even feel depressed,” one South Korean citizen told the Yonhap News agency.

Experts have pointed to the usual suspects causing what has become an annual crisis, including factories, car exhausts, coal heating and a stagnant air mass. Pollution from factories and emissions being blown across the Yellow Sea in China have also exacerbated the problem.

China

This aerial view shows the tops of highrise buildings poking out from heavy fog in Yangzhou, in China's eastern Jiangsu province on January 14, 2019.