Last December, ultrafine dust concentration improved… ‘Effects’ of the 2nd seasonal management system

In December of last year, the first month of the implementation of the second fine dust seasonal management system, air pollutants such as ultrafine dust were found to have improved overall due to the government’s policy effects.

On the 19th, the Ministry of Environment released the analysis results on the ultrafine dust situation and major implementation results in December of last year, the first month of the implementation of the second fine dust seasonal management system (December 1, 2020 to March 31, 2021).

◇ Improve the concentration of ultrafine dust… Impact of performance of policy tasks

The concentration of ultrafine dust (PM2.5) was found to have improved overall compared to the past.

The average concentration of ultrafine dust nationwide for one month in December of last year was 24.1㎍/㎥, about 8% (1.7㎍/㎥) compared to 25.8㎍/㎥ in December 2019, and the average in December for the last three years (2017-2019). Compared to the concentration of 27㎍/㎥, it improved by about 11%.

In addition, the number of’good’ days under the national average daily ultrafine dust concentration of 15㎍/㎥ was 10 days, an increase of 4 days compared to December 2019.

The number of’bad’ days with an average of 36㎍/㎥ or more per day was 5 days, a decrease of two days from December 2019.

On the other hand, it was analyzed that the influence of the weather on the concentration of ultrafine dust during the same period was caused by a combination of unfavorable conditions.

Compared to December 2019, the average wind speed increased (1.8→1.9m/s) and the airflow was smooth due to the strong expansion of the cold and dry continental high pressure.

However, the fact that the precipitation during the same period decreased by about 70% (30.3→9.2mm) and the number of days in the east wind decreased (6→0 days) was a disadvantage.

As a result of analyzing the performance of the 2nd seasonal management system during the same period, it was found that air pollutant emission reduction performance was large in the field of coal-fired power plants and workplaces with voluntary reduction agreements.

During the seasonal management period, a total of 324 workplaces participated to implement voluntary reduction agreements such as optimal operation of air pollution prevention facilities, among which air pollutants were discharged as a result of analyzing data from 137 workplaces equipped with a remote chimney monitoring system (TMS). The total amount decreased by about 4,571 tons (44.8%) compared to December 2019, compared to December 2018, before the enforcement of the seasonal management system.

In particular, of the total 60 units nationwide, 12 to 17 units of coal-fired power plants are suspended per day, and for 26 to 46 units, an upper limit limit of 80% of the maximum power generation has been implemented to reduce the number of units.

As a result, the total amount of air pollutant emissions was reduced by about 1836 tons compared to December 2019, and about 5,254 tons (59.8%) decreased compared to December 2018, before the implementation of the seasonal management system.

In addition, the second seasonal management system was implemented in December 2020 due to the operation of the ship’s low-speed navigation system and early scrapping of old diesel vehicles. The total amount of air pollutants related to ultrafine dust was up to about 31,857 tons compared to before the implementation of the seasonal management system for one month. Reduced.

[표] Comparison of air pollutant emissions at coal-fired power plants and voluntary agreement workplaces

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