Assessment of the impacts and transmission of coronavirus observed in the Republic of Korea in 2020–2021

The pandemic of Coronavirus diseases occurred in the Republic of Korea from 19 January 2020. By March 2020, Korea had reported the second largest number of Coronavirus patients in the world. On the anniversary date (2021), however, with a 51.3 M population, Korea has had 73.115 K patients with 1.283 K deaths, and this stands at 86th in the world. On average, Korea has 14.3 patients per 10,000 people. Air-parcel trajectory analysis and airflows show that in the general westerly region, air parcels and pollutants could flow out and in all directions. This suggests initially that Coronaviruses from source areas in China could transmit to many sink regions and sectors including 228 subdivided counties in Korea. However, there were only relatively small numbers of Coronavirus patients in western sea sides of the Korean Peninsula in comparison with large numbers of Coronavirus disease patients in cities and in eastern sides. In particular, three counties in Korea, including Ong-jin, Mooju and Chang-heung, have zero patients of Coronavirus diseases. This suggests that a long-distance transmission of Coronavirus from Wuhan and other infected cities in China to western Korea likely did not occur. Moreover, there was no evidence on the potential transmission of Coronavirus from neighboring large cities to the above-mentioned isolated counties in Korea which are only 10 ~ 50 km away. In the biosphere, during the transmission stage, the inactivation of Coronavirus by UV rays appeared to occur effectively in 30 ~ 120 min, in agreement with the result of satellite and modeling studies. In turn, the air transmission of Coronaviruses and pollution from China and neighboring cities in Korea apparently had no impact to cause Coronavirus diseases at the 228 counties in Korea. The infection and spreading of Coronavirus diseases to other people in Korea mainly appeared to occur in confined indoor air environments. With the absence and lack of UV rays in indoor environments, Coronaviruses would be active there for hours or days longer than in the outdoor environments.