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, (СН)NNH) and NT (nitrogen tetroxide, NO) - and their transformation products (NDMA (nitrosodimethylamine, (CH)NNO), NO, NO and NH) 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, NO - 19, NH - 0.04 and NO - 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 and 82 mg/m/day, respectively. The maximal permissible addition (MPA) for UDMH, NDMA and NO to the 0-5 cm layer of soil was estimated at 0.06, 0.006 and 70.2 mg/m, respectively. At the second stage FR in the NE Altai, substances released by space transportation were absent and the concentration of NO and NH 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.