Snow pollution by nitrogen-containing substances as a consequence of rocket launches from the Baikonur Cosmodrome

In this paper, we assessed snow pollution by nitrogen-containing substances including rocket propellants - UDMH (unsymmetrical dimethylhydrazine, (CH3)(2)NNH2) and NT (nitrogen tetroxide, N2O4) - and their transformation products (NDMA (nitrosodimethylamine, (CH3)(2)NNO), NO3-, NO2- and NH4+) within the falling regions (FRs) of the first and second stages of Proton-M rockets launched from the Baikonur Cosmodrome. At the first stage FR in Central Kazakhstan, snow with a pH range from 1.7 to 9.0 was contaminated by N-containing substances (maximal value in g/L): UDMH - 0.27, NDMA - 0.04, NO3- - 19, NH4+ - 0.04 and NO2- - 0.13. The first stage landing resulted in snow contamination by soil dust particles and N-containing substances at a rate of 13 g/m(2) and 82 mg/m(2)/day, respectively. The maximal permissible addition (MPA) for UDMH, NDMA and NO3- to the 0-5 cm layer of soil was estimated at 0.06, 0.006 and 70.2 mg/m(2), respectively. At the second stage FR in the NE Altai, substances released by space transportation were absent and the concentration of NO3- and NH4+ corresponded to the natural background level. The index of contamination (IC) was used for characterizing the degree of snow contamination by N-containing substances. A simulation model was developed for analysing the dependence of snow contamination by rocket propellant components on the weather parameters. (C) 2019 Elsevier B.V. All rights reserved.