title: Population dose due to natural radiation in Hong Kong.
abstract: In densely populated cities such as Hong Kong where people live and work in high-rise buildings that are all built with concrete, the indoor gamma dose rate and indoor radon concentration are not wide ranging. Indoor gamma dose rates (including cosmic rays) follow a normal distribution with an arithmetic mean of 0.22 +/- 0.04 microGy h(-1), whereas indoor radon concentrations follow a log-normal distribution with geometric means of 48 +/- 2 Bq m(-3) and 90 +/- 2 Bq m(-3) for the two main categories of buildings: residential and non-residential. Since different occupations result in different occupancy in different categories of buildings, the annual total dose [indoor and outdoor radon effective dose + indoor and outdoor gamma absorbed dose (including cosmic ray)] to the population in Hong Kong was estimated based on the number of people for each occupation; the occupancy of each occupation; indoor radon concentration distribution and indoor gamma dose rate distribution for each category of buildings; outdoor radon concentration and gamma dose rate; and indoor and outdoor cosmic ray dose rates. The result shows that the annual doses for every occupation follow a log-normal distribution. This is expected since the total dose is dominated by radon effective dose, which has a log-normal distribution. The annual dose to the population of Hong Kong is characterized by a log-normal distribution with a geometric mean of 2.4 mSv and a geometric standard deviation of 1.3 mSv.
authors.affiliation: Radioisotope Unit, The University of Hong Kong, Hong Kong.
authors.forename: M Y
authors.initials: MY
authors.lastname: Tso
authors.forename: J K
authors.initials: JK
authors.lastname: Leung
mesh_terms: D005720:Gamma Rays / Q000009:adverse effects; D006283:Health Physics; D006723:Hong Kong; D006801:Humans; D011827:Radiation; D011829:Radiation Dosage