The Ministry of Environment (Minister Cho Myung-rae) announced on May 12th the outcome of the impact of the Seasonal Management System of Fine Dust which was run from December 1st last year to March 31st 2020.

The Seasonal Fine Dust Management System aims to mitigate the intensity and frequency of high-concentration fine dust during a period when fine dust concentration is anticipated high. It is a more strengthened measure than the usual responses that at the same time protects the citizen's health.

The system was first decided to be introduced at the 3rd Fine Dust Special Measures Committee which took place on November 1st following the public policy suggestion from the National Council on Climate and Air Quality in September 2019. A total of 28 action tasks were chosen to be implemented, including suspending or capping operations of coal-fired power generation (see Annex 1).

On April 1st, the government revealed that the average ultrafine dust concentration levels had improved by around 27% (33→24㎍/㎥, △9(8.9)) compared to the same period last year, reporting the performance of each action task implemented during the fine-dust management season at the same time.

This time, it made a comprehensive analysis and reported on its policy effect, which includes the sources contributing to the improvement of ultrafine dust levels during the observed period such as a favorable weather condition. 

<Estimation of domestic fine dust reduction during the seasonal management period>

An estimated of up to 22,000 ton* of ultrafine dust emissions is reported to be mitigated in Korea since the System was put in place.

*The figure includes the converted unit that allows simpler comparison between direct emission (primary emission) of ultrafine dust(PM2.5) and the transformed volume of SOx and NOx into ultrafine dust in the air (secondary emission).

The reported volume of reduced domestic ultrafine dust from December 1st to March 31st is 19.5% less than that of the same 4 months in 2016, which is close to the initial 20% reduction goal suggested by the National Council on Climate and Air Quality (NCCA).

Amongst the suggested actions by the NCCA, the restriction on the operation of 5-grade vehicle in the Seoul Metropolitan Area was not implemented as the related law amendment bill submitted has made some delays.

Yet still, 113,000 vehicles that are graded at 5th were reduced thanks to the strengthened publicity and government supports in early scrapping of grade 5 automobiles and installing emission-reduction equipment. Additionally, the registered number of 5-graded vehicles as of late 2019 was reduced by 478,000 compared with late 2018.

By substance, direct emissions of ultrafine dust(PM2.5) was estimated to be cut by 5,600 ton, Sox by 34,000 ton, NOx by 58,000 ton, VOCs by 19,000 ton during the observed seasonal management period.

<Analysis of the policy effect during the fine dust seasonal management period>

It was analyzed that the implementation of the Fine Dust Seasonal Management System proved to be effective in mitigating the frequency and intensity of highly concentrated fine dust, which was the initial policy goal.

The National Fine Dust Information Center, an affiliate organization of the Ministry of Environment, simulated a mathematical modelling of the concentration changes by the reduced volume of ultrafine dust emissions before and after the System. It ed significant differences in the fine dust 'bad' day counts and daily average concentration levels.

First, on the frequency of high concentration, the Seasonal Management System was analyzed to contribute to reducing fine dust 'bad' (over 36㎍/㎥) days by 9 days in South Chungcheong Province (highest), 4 days in South Jeolla Province, and 2 days in Seoul, with the national-wide average of 2 days.

As for the intensity of high concentration, thanks to the System, the daily average of ultrafine dust concentration was improved by 7.5㎍/㎥ in Sejong (highest), 6.8㎍/㎥in Seoul, 6.2㎍/㎥in South Chungcheong Province, and 2.8㎍/㎥ in Jeju (lowest).

In addition, when it comes to the highest concentration by hour, an instantaneous index of high concentration intensity, the analysis showed the highest improvement of 33.1 ㎍/㎥ in Gyeonggi Province, 23.1 ㎍/㎥ in South Jella Province, 20.0㎍/㎥ in North Gyeongsang Province, and 5.6 ㎍/㎥ in Jeju (lowest).

Meanwhile, the average concentration levels during the observed period were analyzed to be ameliorated by 3.9㎍/㎥ in North Gyeongsang Province (highest), 2.7㎍/㎥ in South Jella Province, 2.4㎍/㎥ in South Chungcheong Province, 2.0㎍/㎥ in Seoul, and 0.8 ㎍/㎥in Jeju (lowest). 

The improvement measured in the first half of the period (December 2019 to January 2020) was 1.4㎍/㎥, and 2.5㎍/㎥ in the second half (February to March 2020), with 1.9㎍/㎥ reduction over the four months.

The impact of the Seasonal Management System showed significant regional gap; it was more noticeable in South Chungcheong Province, South Jella Province and North Gyeongsang Province, as the densely located coal-fired power plants and steelmakers in those regions led to the implementation of heavier mitigation measures.

The policy effect of the Seasonal Management System can also be found in the data analysis of the National Institute of Environmental Research, an affiliate organization of the Ministry of Environment.

The findings showed a substantial difference in ultrafine dust levels in Baekryongdo Island and Seoul Metropolitan Area compared between January in 2019 (January 17th ~20th) and 2020 (January 1st ~ 4th), a period when the weather condition was similar and the COVID-19 impact was minimal.

Despite the comparable weather conditions including the intensity of overseas inflow of fine dust and stagnant air in the atmosphere in country, the concentration levels of ultrafine dust in January last year increased up to 'very bad' (over 76㎍/㎥) whereas in January this year, it did not show a dramatic increase.

In addition, from last January's case, the additional increase of the nitrate level in the Seoul Metropolitan Area was particularly noticeable following the increase in Baengyeongdo Island that normally has a profound overseas influence.

However, as the case of January this year did not point to a substantial increase in the nitrate level in the Seoul Metropolitan Area after the increase in Baengyeongdo Island, it can be interpreted as a proof that fine dust emissions in the Seoul Metropolitan Area were reduced.

<External influence apart from the domestic policy impact>

Factors such as more days with easterly wind (7→22 days) and heavier rainfall (111→206mm) were analyzed to contribute to improving ultrafine dust condition during the seasonal management period.

According to a replicate mathematical modelling run by the National Fine Dust Information Center on the weather-induced differences in ultrafine dust concentration levels between the seasonal management period and the same period last year, the national average of ultrafine dust concentration was estimated to be lower by 3.0㎍/㎥ due to a more favorable weather condition during the seasonal management period compared to the same period of last year.

The mitigation effect was measured to be 0.2㎍/㎥ in the first half of the observed period, while 5.8㎍/㎥ in the second half based on the influence of favorable weather.

Other than the impact of Seasonal Fine Dust Management System and the weather conditions in general, it was also analyzed that the mitigation policy of China, the outbreak of COVID-19, and comparably warmer winter season in Korea combined contributed to ameliorating national ultrafine dust concentration levels.

First of all, China had implemented its fine dust reduction measures, similar to Korea's Seasonal Management System, in three focus areas* during the fall and winter season from October 2019 to March 2020.

* Beijing Cluster (Beijing, Tianjin, Hebei) and surrounding region, Fen-Wei Plain, Changjiang Delta

Second, the outbreak of COVID-19 discouraged economic activities in China resulting in reduced traffic, which could be understood as a source of emissions reduction compared to previous years.

Yet, analyzing the exact volume of emissions reductions in China was limited to some extent on the Korean side, and the Chinese government shared the same position.

On April 28th, when Korea and China had their first video conference on sharing seasonal fine dust management policy, China shared that in February they had an obvious impact of COVID-19 on the fine dust level, but for the actual estimation during the Seasonal Fine Dust Management period, more detailed analysis needs to be carried out.

Yet, the simulation showed that the estimated impact of China's seasonal mitigation policy measures together with COVID-19 was believed to contribute to reducing the average ultrafine dust level in Korea by approximately .1~2.8㎍/㎥.

From December 2019 to January 2020, a period when the external conditions are more or less identical with little COVID-19 impact and similar weather conditions, China's influence was estimated to mitigate the average concentration of ultrafine dust levels in Korea by around 1.1㎍/㎥. 

Also noteworthy is the domestic impact of Seasonal Management System, which was estimated to reduce the average concentration levels of ultrafine dust by 1.4㎍/㎥.

Meanwhile, the warm temperature and the COVID-19 pandemic also had an additional mitigating impact of fine dust emissions in Korea.

In fact, during the seasonal management period, the average temperature was 2.4 ℃ higher than the usual, and based on this, the reduced demand for domestic heating was analyzed to contribute to lowering fine dust emissions.

On this front, the gas use showed an actual decrease by 7% in December 2019 and 10% in January 2020.

In addition, the outbreak of COVID-19 lowered the highway traffic and flight demands as they were reduced by around 10% and 90% respectively in February and March 2020.

However, a mathematical modelling analysis was not carried out as the actual volume of domestic emissions reduction due to COVID-19 and warmer season could not be estimated.

Such impacts as COVID-19 is not in fact counted as one of the seasonal management policy impacts.

<Comprehensive evaluation>

The above findings can be summarized as followings:

First, the Seasonal Management System of Fine Dust was found to be highly effective in reducing the intensity and frequency of high concentration of fine dust, which meets the initial policy goal.

Second, the System contributed to mitigating the average concentration levels by about 34% (△1.4㎍/㎥) even during the first half of the observed period when the external influences such as weather and COVID-19 were minimal. This can be interpreted that the Seasonal Management System of Fine Dust was effective in improving the average concentration levels of fine dust.

The fine dust mitigation was greater in the second half (2.5㎍/㎥) of the observed period than the first half (1.4㎍/㎥) as the System gradually stabilized. However, its contribution was found to be relatively low due to a greater external influence including weather condition and overseas factor.

Third, considering the regional gaps of the policy impact, the next phase needs to target nation-wide improvement.

Fourth, the Fine Dust Seasonal Management System and COVID-19 led to significant reduction of pollutants emissions, and it was proved to substantially improve fine dust concentration levels.

Last, the impact of weather condition in the second half of the seasonal management period (February to March 2020) paradoxically implies that the weather can be a risk factor at any time. This indicates that it is necessary to strengthen the next phase of seasonal management system to secure consistent policy impact.

<Conclusion>

With the announced findings as a basis, the Ministry of Environment will take necessary steps to implement the second Seasonal Fine Dust Management System in cooperation with related ministries. 

To begin with, the Ministry will analyze the dataset and methodology in more details with the National Fine Dust Information Center and the National Institute of Environment Research, which will also be shared with individual experts, considering that it was the first time that the system was introduced and that there were a number of variables affecting the results this time such as warmer weather and the outbreak of COVID-19. Based on the discussions, some modifications on the methodology can be made for improved analysis.

Additionally, it will estimate co-benefits of the Seasonal Fine Dust Management policy including greenhouse gas emissions reduction, adding to the improvement of fine dust levels.

In the meantime, the Ministry will carefully examine the effectiveness and receptivity of each action task of the System. Then taking the outcome of public hearing into consideration, it will further improve the next Seasonal Management System. 

Director General Geum Han-seung of the Air Quality Policy Bureau at the Ministry of Environment said "although there were government-led policy efforts, it is the people who did not hesitate to participate in the Seasonal Fine Dust Management System and share the burden as a society. This is what made the first Seasonal Management System of Fine Dust effective to some extent. I really appreciate it."

He also added that "the government is strongly determined to go all-out in planning the next Seasonal Management System of Fine Dust, so that, in Korea, anyone can enjoy clean air wherever and whenever."