Fine Dust: Is It Really Fine?
Fine Dust: Is It Really Fine?
  • Reporter Lee Ha-jun
  • 승인 2018.03.28 12:52
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▲Picture of Seoul with severe fine dust level / JoongAng Daily
▲Picture of Seoul with severe fine dust level / JoongAng Daily

Last January, the Seoul Metropolitan Government enforced the ‘Free Public Transportation’ policy during commuting times to reduce the level of fine dust in the air. This policy became a hot potato, and people argued whether it was an efficient policy or not. Some criticized that it was a waste of budget, and had inadequate results. Nevertheless, one thing is for sure. People are now aware of this problem, which is inspiring.


What is fine dust? The official term for fine dust is ‘Fine Particulate Matter’, and it is abbreviated as PM. Fine dust is classified into two groups: PM10 and PM2.5. PM10 is what we usually call fine dust and it has a diameter between 2.5μm and 10μm. PM2.5 is called ultrafine dust and its diameter is shorter than 2.5μm. It originates from gas emitted from cars, factories, or burning fossil fuels. There are two typical routes of fine dust production. The first route is direct emission of the solid particles from the source, and the second route is chemical combinations of gas from the source with already existing compounds in the atmosphere. An example of the first route can be solid dust from construction fields, and example for the second route could be sulfur oxides combining with NH3 or H2O.What’s so dangerous about it is that the particles are toxic and can pass through our respiratory systems, ultimately damaging them. Also, fine dust is designated as a first class carcinogenic substance by the World Health Organization(WHO). Because the particles are so small, it not only damages the respiratory system, but also infiltrates into our blood and circulates throughout our body.


Problems are emerging due to the increasing levels of fine dust, and last January had abnormally high levels. During the third week of January, Seoul’s level of air pollution was 100 at its highest and 73 at its lowest. Comparing this with the standards of the Korean Ministry of the Environment, 100 and 73 are both moderate levels. However, when we compare this with WHO’s recommended standards, we can see that they are both unhealthy levels. Because Korea has relatively mild standards, it is easy to become insensible about the severity, but it is necessary to be conscious about it.


Then who is responsible for this situation? Many people blame China for it, and partly it is true. However, domestic contributions cannot be disregarded. The ratio between internal and external contribution in fine dust production is known as 45:55 averagely, and it can differ depending on the atmospheric condition. For instance, when the atmosphere is tied-up in one place, chemical reactions with sulfur oxides or nitric oxides become active and lead to increased secondary fine dusts. When Seoul enforced the policy, which was Jan. 15~18, domestic contribution was actually higher, starting as 43% and increased to 62%.


It is not reasonable to just sit around and blame other countries about this crisis. Prevention should be a priority above all. Individuals have to check the atmosphere status regularly and use masks. Not using cars voluntarily would be helpful. Governmental efforts can be such as development of new renewable energy, campaigns, policy making, and cooperation with neighboring nations. Spring, which is the season of blooming flowers, but also Asian dust phenomenon, is coming. How about checking the atmosphere status today?