Concentration variability of atmospheric radon and gaseous pollutants at background area of Korea between 2017 and 2018

The concentrations of radon in the atmosphere were measured at the Gosan site of Jeju Island during 2017-2018, in order to investigate the time-series variation characteristics and the dependency of airflow transport pathways. The mean ²²²Rn concentration was 2,480 mBq m^-3, and its monthly concentration in November was 3,262 mBq m^-3, more than twice as that in July (1,459 mBq m^-3). The diurnal radon concentrations increased throughout the nighttime to the maximum (2,862 mBq m^-3) at around 7 a.m., then gradually decreased throughout the daytime by the minimum (1,997 mBq m^-3) at around 3 p.m. The seasonal and monthly variations of CO, NO₂, O₃ showed a roughly similar pattern to that of radon for the same period, as high in winter and low in summer. The cluster back trajectory analysis described that about 60 % of overall airflow pathways was influenced by the airflow from China. The concentrations of radon and gaseous pollutants were relatively high as the airflow was influenced by China continent, but comparatively much lower as influenced by the northern Pacific Ocean.