The season of fine dust has begun. With high concentration of fine dust from China, the blue sky turned gray in the west, such as Seoul, Gyeonggi, and Chungcheong. Although the fine dust concentration did not increase as much as the original forecast, the first high dust concentration preliminary reduction measures were issued in Seoul, Gyeonggi and Incheon on the 21st.

In recent years, the average daily concentration of ultrafine dust (PM 2.5) in Seoul has remained around 10 µg / ㎥, which is a good level on the 18th and 19th, but from 20 to 22 days as fine dust from China came in. It climbed up and down to 25µg / ㎥, which is the 'normal' level. Although it did not reach the 'bad' level as predicted, the ultra-fine dust concentration rose by more than 10 µg / m 3 in just one day (see figure below).
How does our body react when the concentration of fine dust rises in a relatively short period of time, such as once the fine dust from China has passed? How does exposure to high levels of fine dust in a short period of time affect my health?

The results of the study show that short-term exposure to high concentration of fine dust has a great effect on health as well as long-term exposure. However, there is some controversy or misunderstanding in Korea. The major impact on health was the long-term exposure to fine dust, so the measures should be made accordingly.

Lowering the average condition over time is important, of course. However, it is also very important to prepare for high concentration of fine dust for a short time. Short international exposure to high levels of fine dust can have a significant impact on health, according to a large international joint study.

Recently, 49 scholars who have studied fine dust and health in Korea, China, Australia, the United States, the United Kingdom, and Spain, including Seoul National University Graduate School of Public Health, Professor Kim Ho A study of the correlation between dust concentration and mortality was published (Liu et al., 2019).

In order to analyze how short-term high-level fine dust exposure affects mortality, the team studied daily fine dust (PM 10) and ultra-fine dust (PM 2.5) concentrations in each region and daily deaths from 1986 to 2015. The number was analyzed. Many institutions and researchers have been studying different regions and periods of time, but this is the first time many scholars and countries have participated and have done large-scale research on various regions on a unified basis.

According to the study, when the average daily concentration of fine dust (PM 10) is 10 µg / m3 higher than the previous day, the number of deaths from all diseases increases by 0.44% on average, and 0.36% of deaths from cardiovascular diseases and respiratory diseases. Death toll increased by 0.47%.

In particular, as shown in the Seoul, Gyeonggi, and Incheon metropolitan areas, when the concentration of ultrafine dust (PM 2.5) is 10 µg / ㎥ higher than the day before, the death rate increases more than when the concentration of fine dust increases 10 µg / ㎥. All disease deaths increased by 0.68 percent, cardiovascular deaths by 0.55 percent, and respiratory deaths by 0.74 percent. Short-term exposure to high levels of fine dust also has a significant health impact (see figure below).
Of course, there are limitations to research. The study sheds light on statistical correlations, not on the mechanisms or causality of how high levels of fine dust exposure specifically lead to death. The analysis was conducted on 262 cities around the world, but the analysis was conducted in regions with sufficient data such as the US, China, Japan, and Spain.

Despite the limitations, the findings are statistically significant to show that high levels of fine dust compared to the previous day can cause significant health problems as well as long-term exposure. In particular, people suffering from various diseases, including heart and respiratory diseases, show that short-term exposure to high concentrations of fine dust may worsen or endanger the disease.

In the long run, measures to lower the average of fine dust are important, but short-term measures such as fine dust reduction measures are very important when considering health effects. Especially for the general public, it is most important to avoid high concentration of fine dust. People with various diseases, such as respiratory disease or cardiovascular disease should be avoided even higher concentration of fine dust. Although it may not be much compared to long-term exposure, high concentrations of short-term fine dust may also lead to premature death.

It is especially important for the government to provide information as early as possible so that people have sufficient time to prepare and avoid high concentrations of fine dust. The fine dust forecasting period, which is currently 2 to 3 days long, should be extended to at least one week, and the accuracy of high concentration fine dust forecasting should be drastically increased. Providing accurate information early enough can prevent the high concentration of fine dust and maximize the effectiveness and protect the health of the people.

<Reference>

* C. Liu, R. Chen, F. Sera, AM Vicedo® Cabrera et al., Ambient Particulate Air Pollution and Daily Mortality in 652 Cities, The New England Journal of Medicine, 2019; 381: 705-15. DOI: 10.1056 / NEJMoa1817364

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