0750 GMT March 25, 2019
The level of PM2.5 fine dust particles reached an average of 73 micrograms per cubic meter of air in districts in Seoul Sunday morning, according to the National Institute of Environmental Research (NIER), a government-established think tank, koreajoongangdaily.joins.com reported.
Through Sunday, the level rose to an average of 80 micrograms in Seoul.
PM2.5 fine dust particles are particles less than 2.5 micrometers in diameter and about 30 times smaller than the width of a human hair. The World Health Organization (WHO) describes them as carcinogenic since PM2.5 particles can travel through the respiratory tract and reach the bloodstream, causing lung cancer and other lung conditions, as well as heart conditions and strokes.
The levels in Seoul Sunday were triple the recommended level of daily exposure to PM2.5 by the WHO, which is 25 micrograms.
Most of the country experienced unhealthy levels of fine dust particles in the air. The level of PM2.5 reached 85 micrograms in the afternoon in Gyeonggi, 81 micrograms in Sejong and 93 micrograms in North Chungcheong.
NIER categorizes the level of PM2.5 in the air in four levels: Very unhealthy if there are more than 76 micrograms; unhealthy if there are between 36 to 75 micrograms; moderate if there are between 16 to 35 micrograms; and good if there are between 0 to 15 micrograms.
NIER said that in areas experiencing unhealthy to very unhealthy levels of PM2.5, residents must avoid prolonged outdoor activities. The Seoul city government closed down its open-air ice skating rink in front of City Hall Sunday.
Some parents with young children found indoor spaces to spend the weekend together.
You have to wait about an hour in the queue before you can enter,” one employee of an indoor playground told a parent in Yeouido, western Seoul.
“The place is especially popular today, probably because of the fine dust in the air.”
NIER forecast that due to stagnant air and inflowing fine dust particles from outside of the country, the high levels of fine dust will persist Monday throughout the country.
There have been disagreements on how much of the fine dust particles in Korea are domestically produced or inbound from overseas.
In joint research conducted in May and June 2016 between NIER and NASA, 52 percent of the air pollutants in the country were found to have been produced locally, while 48 percent were attributed to external factors — about 34 percent of which were from China.
But the general perception in Korea remains that fine dust particles from China are the main cause of air pollution — 52 percent of people surveyed by the Korean Ministry of Environment in October last year said China is the main cause of air pollution in Korea.
A spokesperson for the Chinese Ministry of Ecology and Environment, Liu Youbin, refuted this on Dec. 28, when she said in a press briefing that the air quality in China has improved over the years through regulatory measures, while that of Korea has deteriorated in the same period.
“For fine dust particles from China to land in Korea, they will have to travel on the uppermost level of the atmosphere,” an air quality expert from the Chinese Academy of Sciences told the JoongAng Ilbo on the condition of anonymity.
“I think only 10 percent of Beijing’s fine dust particles will travel that high and into Korea.”
Some experts have pointed to emissions from ports along the coastal regions of China as sources of air pollution in Korea.
“It’s true that there are lots of air pollutants coming from these ports,” one air quality expert told the JoongAng Ilbo.
“But there haven’t been studies on this topic in China yet.”
NIER analyzed the monthly level of fine dust particles from 2015 to 2017 and concluded that 19 to 67 percent of fine dust particles in the air were inbound from elsewhere. The percentage tended to be higher in the winter, it said. Of the inbound particles, it said that those from China took up some 30 to 40 percent.