VNU Journal of Science Earth and Environmental Sciences, Vol 37, No 4 (2021) 1 8 1 Original Article Assessment of Natural Radioactivity Levels and Estimation of Radiation Dose by Inhalation Environmental Air Samples from Hanoi Hoang Anh Le1,*, Nguyen Viet Thanh1, Bui Duy Linh2 1VNU University of Science, Vietnam National University, Hanoi 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam 2Department of Chemistry and Environment, Vietnam Russian Tropical Centre 63 Nguyen Van Huyen, Nghia Do, Cau Giay,[.]