title: Fluctuations of exposure rate at regional radiation monitoring stations in Korea.
abstract: Based on hourly means of exposure rate between August 2000 and July 2001 at nine Regional Radiation Monitoring Stations (RRMS) in Korea, we analyzed spatio-temporal characteristics of exposure rate. The mean and fluctuations of exposure rates were 99 and 3.8 nGy h(-1), respectively. The hourly exposure rate over 9 RRMS indicated a diurnal pattern with the exposure rates reaching a maximum between 5:00 and 8:00 a.m. in the early morning and a broad minimum between 4:00 and 10:00 p.m. in the afternoon. The fluctuations of exposure rate in the inland areas were less than 3.2 nGy h(-1), and those of exposure rate in coastal areas were larger than 3.9 nGy h(-1). The frequency distribution of exposure rates had one peak around the mean and was to be skewed to the right or positively skewed and its tails were fatter than those of a normal distribution. The interrelations of exposure rates at each station generally decreased with the distance between the stations. Empirical orthogonal function (EOF) analysis showed that almost all (99.9%) of exposure rate fluctuations were described by simultaneous variations. The spatial distribution of the first EOF modes of actual, low-pass (periods longer than one month) and high-pass (periods shorter than one month) exposure rate series were similar to each other.
authors.affiliation: Environmental Radioactivity Assessment Department, Korea Institute of Nuclear Safety, Kusung-Dong 19, Yusong, Taejeon, 305-338, South Korea. k166csw@kins.re.kr
authors.forename: Seok-Won
authors.initials: SW
authors.lastname: Choi
authors.forename: Jung-Whan
authors.initials: JW
authors.lastname: Row
authors.forename: Hong-Mo
authors.initials: HM
authors.lastname: Park
authors.forename: Chang-Kyu
authors.initials: CK
authors.lastname: Kim
authors.forename: Byung-Hwan
authors.initials: BH
authors.lastname: Rho
authors.forename: Ju-Yong
authors.initials: JY
authors.lastname: Yun
mesh_terms: D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D006801:Humans; D007723:Korea; D010507:Periodicity; D011848:Radioactive Pollutants / Q000032:analysis*; D018570:Risk Assessment
chemical_list: D011848:Radioactive Pollutants