Bài viết trình bày kết quả nghiên cứu về nồng độ khí radon (222Rn và 220Rn) và các yếu tố ảnh hưởng bên trong nhà trình tường, một loại nhà truyền thống ở Cao Nguyên Đá Đồng Văn. Nồng độ khí radon được đo trong tháng 12/2016 và tháng 7/2017, tiêu biểu cho tháng “lạnh” và tháng “nóng” trong năm, bằng thiết bị cầm tay RAD7. | Nội dung Text Nồng độ khí radon trong nhà trình tường và các yếu tố ảnh hưởng lấy ví dụ ở khu vực Cao Nguyên Đá Đồng Văn tỉnh Hà Giang VNU Journal of Science Earth and Environmental Sciences Vol. 36 No. 1 2020 1-10 Original Article Radon Concentrations and their Controlling Factors in Mud-built Houses in Dong Van Plateau Karst Geopark Ha Giang Province Nguyen Thuy Duong1 Nguyen Anh Nguyet1 Nguyen Van Huong1 Jan Schimmelmann2 Nguyen Dinh Thai1 Arndt Schimmelmann3 1 VNU University of Science Vietnam National University Hanoi 334 Nguyen Trai Hanoi Vietnam 2 University of Bremen Institute of Geography Celsiusstrasse FVG-M D-28359 Bremen Germany 3 Indiana University Department of Earth and Atmospheric Sciences 1001 East 10th Street Bloomington Indiana 47405-1405 USA Received 30 January 2020 Revised 05 March 2020 Accepted 12 March 2020 Abstract This article presents results of radon 222Rn and thoron 220Rn concentrations in room air measured inside mud-built houses that are traditional dwellings on the Dong Van Karst Plateau. The measurements were conducted in December 2016 and July 2017 corresponding to cold and warm months respectively by using a portable RAD7 detector. Our results show that 222Rn and 220 Rn concentrations were elevated during the warm month and the concentrations of 220Rn were always higher than the respective 222Rn values at the same measured locations during the two months. The relatively long half-life of 222Rn days causes efficient dispersion and loss from room air due to air ventilation. In contrast the much shorter half-life of 220Rn seconds results in elevated radiation near mud surfaces prior to attenuation into room air further away from walls and floors. Average concentrations of 220Rn in room air during both cold and warm months are much higher than in normal outside air 10 Bq m-3 . The severely elevated concentrations of 220Rn in room air of mud-built homes are likely harmful to human occupants especially to those sleeping near .