1. S. A. Ugryumov, Pol. Sci. Ser. D, No. 10, 14–16 (2008).
2. Encyclopedia of Occupational Safety and Health, in 4 vols. (Profizdat, Moscow, 1985), Vol. 3 [in Russian].
3. V. A. Bazhenov, in Harmful Chemicals. Radioactive Substances, Eds. by A. A. Il’in and V. A. Filov (Khimiya, Leningrad, 1990) [in Russian].
4. Hygienic Standards 2.1.6.1338-03. The Maximum Permissible Concentration (MPC) of Pollutants in the Air of Populated Areas. http://www.ohranatruda.ru
5. GOST 12.1.005-88. Standard 12.1.005-88. General Hygiene Requirements for Working Zone Air (Izd. Standartov, Moscow, 2004), p. 48 [in Russian].