According to the “State of Global Air 2017,” a report by nonprofit environmental group Health Effects Institute in the United States, South Korea’s average population-weighted concentration level of PM2.5 － which refers to ultrafine particles or particle matter with a diameter of 2.5 micrometers or less － was 29 micrograms per cubic meter in 2015, above the average 15 micrograms for the Organization for Economic Cooperation and Development countries.
South Korea’s reading trailed only Turkey among the OECD. When compared to other Asian countries, the quality of air in Korea is more polluted than Japan and Singapore, which scored 13 micrograms and 19 micrograms, respectively. China recorded 58 micrograms.
While many have pointed to China as the main culprit, the South Korean government highlights emissions from diesel engine cars and business sites dealing with construction waste or using solid fuel.
The Environmental Ministry last June came up with fine dust countermeasures, including a weekly no-driving campaign and gradually cutting down on benefits given to diesel car owners, with an aim of improving the country’s air quality to levels equivalent to European countries in 10 years. However, the government’s plan did not gain wide support from the public.
trail：動詞，拖曳、跟隨在後面。My daughter went to her room, trailing her Elsa doll behind her.（我女兒去她房間，後面拖著她的艾莎娃娃。）
deteriorate：動詞，惡化。deteriorating為其現在分詞，指持續惡化的。A patient with a deteriorating heart condition requested to see a doctor.（心臟病不斷惡化的病人亟需醫師診治。）
cut down on：動詞片語，削減。The doctor told the old man to cut down on his drinking.（醫師告訴老年人少喝酒。）