The grey and hazy days are getting frequent and rising as a serious issue. The main culprit of this phenomenon is fine dust. Korea’s Ministry of Environment selected “A marked decrease in fine dust concentration” as one of the four major promises to the public in 2019. In other words, Korea’s air pollution due to fine dust is an acute problem that needs to be addressed at a national level. However, although the populace has heard of this problematic situation, they do not know exactly what is going on around them. In response, The Argus sheds light on fine dust, a menace to the lives of many people.
The common misconceptions about fine dust
>>> Is there little difference between yellow dust and fine dust? (X)
Yellow dust and fine dust differ in the cause and composition. First, yellow dust is a natural phenomenon originated from the dry areas of China or Mongolia. On the other hand, fine dust is a man-made calamity formed by industrial activity or vehicle exhaust. Also, yellow dust itself does not cause serious harm to the human body, as it mainly composes of soil. Meanwhile, fine dust is very harmful because of its high content of heavy metals such as sulfur oxides, arsenic and cadmium.
>>> Is it beneficial to eat pork belly on days with severe fine dust? (X)
A lot of Koreans believe that pork belly’s oil will wash away the dust on the trachea. Thus, they tend to eat pork belly on the days with a high fine dust concentration. However, this is just a superstition stemming from the fact that coal miners, who were often exposed to coal dust, enjoyed eating pork belly after work. In reality, pork belly moves to the stomach through the esophagus, and fine dust flows into the body through the trachea. In other words, the two paths do not overlap at all. Instead of eating pork belly, drinking lots of water is advantageous for health as it helps reduce the concentration of heavy metals in the blood by increasing the moisture content in the blood.
>>> Is the air toxic only when the sky appears hazy? (X)
In some cases, fine dust levels are measured high in spite of the clear blue sky. This results from the difference in a particle’s size between fine dust and ultrafine dust. The particle’s size of ultrafine dust matter is less than 2.5μm in diameter. As ultrafine dust is smaller than fine dust, the particle scatters light better than the one of fine dust. This leads to directly affect one’s range of sight and makes the sky look grey. Because of this reason, the sky can be seen cloudless even when fine dust has high concentrations. Therefore, it is recommended not to assume fine dust concentration based on the color of the sky, but to check it from reliable sources such as Korea Meteorological Administration.
The negative effects of fine dust on health
The trigger for respiratory diseases
Respiratory problems occur when fine dust flows into the respiratory system with oxygen. The particle diameter of fine dust is less than 10μm. In other words, fine dust particle’s diameter is nine times thinner than that of a hair.
“If the particle diameter is thinner than 10μm, it is not filtered by the bronchial tubes, and if it is less than 2.5μm, it can reach the alveolus. Fine dust that enters the body causes inflammation, which adversely affects the bronchial tubes and lungs. In addition, there is no technology to eliminate fine dust from the body,” said Kim Woo-jin, the director of Environmental Health Center in Kangwon National University Hospital.
According to the paper of Korea Centers for Disease Control and Prevention, for every 10μg/m3 increase in fine dust concentration, the hospitalization rate due to chronic obstructive pulmonary disease increases 2.7 percent. Furthermore, as stated by the National Health Insurance Service in January 2019, a total of 4.13 million people went to the hospital in October 2018, when Korea’s ultrafine dust level was “bad.” This significant increase from 4.02 million patients in the same period of 2017 infers that the rapid growth in respiratory diseases in South Korea is related to fine dust.
A cause for vascular and brain diseases
Fine dust in the respiratory system is absorbed into the blood while the lungs are exchanging oxygen and carbon dioxide. Then it moves around every body part through the blood vessels, causing various illnesses. Vascular system is also a victim of fine dust. Arteriosclerosis and myocardial infarction are two possible consequences due to the dust inside the vessel.
Recently, a hypothesis that fine dust can cause brain diseases has been proven by many research studies. In general, when blood enters the brain, a number of pollutants are blocked by the blood-brain barrier. However, as fine dust is small enough to penetrate into the brain, it invades the brain and leads to inflammation, blood clots and stroke. Therefore, fine dust is a time bomb ticking away anywhere in the body.
The results of a study to figure out whether there is a correlation between air pollution and dementia, which was conducted by a United States-Mexico joint research in 2018, are noteworthy. The research team performed autopsies on 203 bodies from Mexico City to check the accumulation of hyper-phosphorylated tau and beta amyloid, the specific proteins accumulated in the brain when dementia occurs or progresses. According to the analysis, these two proteins have begun to accrue in the brain, not only in the elderly but also the children less than a year old when exposed to high levels of ultrafine dust.
The usual suspect of cancer
The International Agency for Research on Cancer classified fine dust as group 1 carcinogen in 2013. The group 1 carcinogen is not suspected to correlate with cancer, but rather a substance that is certain to cause cancer. In short, it is clear that fine dust is a harmful substance that can cause cancer.
In November 2018, Kim Hong-bae, a doctor at the Department of Family Medicine in Myongji Hospital, and Lee Yong-jae, a doctor at the Department of Family Medicine in Gangnam Severance Hospital, released a study about the interrelation between air pollution and cancer mortality. According to a comprehensive analysis of 30 studies about the correlation between air pollution and the risk of death from cancer, the death rate of all types of cancer has risen 17 percent and nine percent respectively, with each increase of 10μg per m3 of ultrafine dust and fine dust.
Another recent study also revealed that fine dust reduces the chances of survival for liver cancer patients. Since the main function of the liver is to decompose toxic substances, patients whose livers do not function properly are more vulnerable to fine dust. According to an investigation by researchers at the University of Southern California in 2017, people who had been exposed to the highest levels of ultrafine dust after being diagnosed with liver cancer have the highest risk of death. In the end, fine dust is not only cancer-causing, but it also exacerbates existing cancer, posing a threat to people.
Where does fine dust come from?
The climate conditions in South Korea
There are various causes of fine dust. However, the majority of fine dust comes from China. This is deeply related to the westerlies blowing in the middle latitudes. The westerlies are prevailing winds from the west toward the east in the regions between latitudes 30 and 60 degrees north and south. As Korea lies between latitudes 33 to 39 degrees north, fine dust from China blows over to Korea on the westerlies.
A recent atmospheric observation at Socheongcho ocean research station has once again proven that fine dust is flowing from China. Socheongcho station is located between Incheon and the Shandong Peninsula of China. Also, there are no industrial facilities within a radius of 50 kilometers. However, fine dust concentration in Socheongcho was 80 percent higher than that of Seoul at the same time. That is to say, Korea’s fine dust is directly associated with China.
Moreover, the northern and central parts of Korea are classified as the Dw, a typical continental climate, in Koppen’s classification of climate. It is characterized by dry winters and wet summers due to the concentration of 60 to 90 percent of precipitation in the summer. When it rains or snows, fine dust in the air is washed away together. However, as neither rain nor snow comes, Korea’s fine dust problem worsens especially in spring and winter.
Another type of fine dust occurring indoors
On the other hand, sometimes fine dust concentrations measure high indoors. They can be divided into two major cases in general. One is fine dust produced from fuels for cooking, and another comes from building materials. When fuels are combusted to make grilled or fried foods, fine dust is generated along with harmful substances such as carbon monoxide and formaldehyde. These gases are blamed for the oxygen deprivation in lungs and increase in lung cancer rates among nonsmokers.
In May 2016, Korea’s Ministry of Environment announced that when grilling mackerel in an enclosed space, 2290μg of ultrafine dust as well as carcinogenic substances formaldehyde and volatile organic compounds are dispersed into the air. In particular, these toxic substances are able to impair immune system and cause respiratory problems to children who sit and play, as these gases are heavier than oxygen.
The powder from cracks in old buildings also creates fine dust. The old cement gets fine cracks in the process of erosion. Through these cracks, a variety of harmful substances and strongly alkaline cement powders come out in the form of fine dust. Another typical hazardous building material that produces fine dust is asbestos. After the fibrous asbestos enters the respiratory system, many immune cells such as macrophages try to digest it. However, asbestos is not decomposed, and immune cells die during digestion. That leads to the extra division of stem cells, resulting in cancer if the cells mutate.
Regulations on diesel and GDI engines
Diesel and gasoline direct injection (GDI) engines are pointed out to be contributing to the increasing concentration of fine dust. First, a diesel engine is an internal combustion engine adopting “diesel cycle.” It has higher fuel efficiency compared to a gasoline engine, but is more destructive to the environment.
“The major two pollutants of diesel engines are hydrocarbon, a black smoke emitted through the exhaust pipe, and nitrogen oxides (NOx) produced during the combustion of diesel fuel. These substances can cause ozone depletion, smog and respiratory diseases,” said Son Byeong-rae, a professor at the Department of Automotive Engineering in Honam University.
The GDI engine is characterized by the direct injection of fuel into the cylinder. GDI engines have the advantage of being able to consume fuel efficiently, but they emit lots of fine dust. Even though cars equip with emission reduction devices such as Diesel Particulate Filter (DPF) and Exhaust-gas Recirculation (EGR), fine dust can be emitted without regular maintenance. Most of all, fine dust problem caused by engines is more serious in that pollutants such as NOx may be transformed into smaller fine dust through the photochemical reaction.
Any feasible solutions?
Resolution of fine dust through artificial rainfall
Fine dust, a man-made tragedy, can be undone by people’s very hands. Artificial rainfall is a type of weather modification that induces rain or snow. The most common way to create artificial rainfall is through cloud seeding. For rain to fall from clouds, a mass of minute liquid droplets, frozen crystals and other particles in the clouds must be heavy enough through condensation. Some materials such as dust and smoke act as condensation nuclei, promoting the unity and growth of cloud particles.
Cloud seeding causes rain by dispersing the cloud seeds, which can serve as condensation nuclei that move into the clouds. As for the cloud seeds, hygroscopic substances such as silver iodide and sodium chloride are mainly used, as they transform the water vapor into raindrops. After a team of U.S. researchers succeeded in cloud seeding by spraying dry ice at a height of 4,000 meters, many countries began to develop the technology of artificial rainfall. The artificial rainfall is used for various purposes, including drought prevention, desertification, and the resolution of fine dust, and China, Israel and the United States are leading countries.
Currently, Korea is at its infancy to accumulate technical skills for artificial rainfall. Compared with the U.S., the technology level is 73.8 percent and the technology gap is estimated to be around 6.8 years. On Jan. 25, 2019, the National Institute of Meteorological Sciences and National Institute of Environmental Research conducted a joint experiment inducing artificial rainfall. Although there are no noticeable results, the artificial rainfall will settle on as a solution for fine dust through continuous efforts.
The formation of urban forests that absorb fine dust
In addition to the function of urban forests absorbing fine dust, they can decrease the concentration of fine dust by moderating humidity and temperature. Also, they have excellent effects on flood control and carbon dioxide reduction. A lot of countries around the world have tried to create urban forests, paying attention to these benefits of the urban forests. Singapore’s Park Connector project and China’s Forest City plan are examples.
The National Institute of Forest Science’s “An analysis on fine dust reduction capacity of the forests” in 2018 shows the outstanding effectiveness of urban forests. The total area of the urban forests is 68,834m2 which was created in Seoul and Incheon in 2017. They absorb 364.7 kilograms of fine dust annually, and this is the same figure when 100 household air cleaners were run for 46 years. Moreover, this size of forests absorbs about 92,954 kilograms of carbon dioxide annually, which is worth about 3,620,000 won (US$3,220), calculated as the price of the carbon bill at the European Climate Exchange.
In particular, if urban forests are created with the consideration of proper species and planting design, the good effects of urban forests can be maximized. According to data released by the National Institute of Forest Science, trees with a complex leaf structure and fast growth rate show fine effects on the reduction of fine dust. For example, zelkova is the most effective tree in decreasing fine dust as a roadside tree, and pine tree has excellent effects in terms of reducing fine dust in the winter and early spring. Building the urban forests based on this information will remedy fine dust problem in an eco-friendly way.
The popularization of electric and hybrid cars
The spread of electric and hybrid cars can reduce the amount of fine dust caused by automobiles. First, the electric car is an automobile that uses electric energy as its power. Unlike the traditional cars that operate with internal combustion engines, there is no pollutant as they generate power through electric motors. Depending on the source they use to make electric power, electric cars are divided into hydrogen cars, solar-cell cars, etc.
Second, hybrid cars are automobiles designed to use more than one drivetrain. It usually uses an internal combustion engine and an electric motor together. The hybrid cars differ from the electric cars in that they are equipped with the internal combustion engines.
“As hybrid vehicles have two or more power sources, they can reduce the use of fossil fuels and produce less harmful materials,” said Professor Son Byeong-rae.
Skeptics of electric cars doubt its effectiveness, as pollutants from electricity power plants are the major contributors to fine dust issue. Professor Son has responded to this by saying, “It is true that the thermoelectric power stations produce a lot of pollutants. However, if we gradually replace these power plants with eco-friendly ones, I think that this limitation will be overcome in the near future.” The hybrid cars are also expected to become eco-friendlier in that fuel cells are being developed to replace internal combustion engines, which produce harmful substances.
Fine dust, often labeled as the “silent killer,” eats up one’s physical health without being noticed. The public should be aware of the dangers of fine dust and try to protect themselves. Solving the problem of fine dust requires considerable concessions in the industrial field and individual economic activities. Also, the government should pay attention to fine dust and make efforts to resolve it. The Argus hopes that fine dust problem will be solved as soon as possible, and imagines a bright future in which people go out freely without masks.
By Na Geum-chae
Associate Editor of Theory & Critique Section