Assessment of contamination by rocket fuel components of remedied sites of silo launchers

Abstract
Introduction. The use of highly toxic and highly hazardous components of liquid rocket fuel in silo-based intercontinental ballistic missiles makes it necessary to assure the health and epidemiological well-being of the population and environmental safety when eliminating silo launchers. The study aims to assess the chemical safety of the sites of silo launchers after their elimination by detonation and remediation of disturbed lands. Materials and methods. Samples of soil, water, vegetation were taken at 20 remedied sites of the former silo launchers of "single start" located in the Chelyabinsk region and the Altai Territory. These samples were analyzed in an accredited laboratory for the content of unsymmetrical dimethyl-hydrazine and its degradation products using certified photometric methods. Results. At the time of the survey in 2019, in 19 of 20 sites of former silo launchers, facts of unauthorized intrusion to the remedied sites were established in order to recover a scrap of non-ferrous and ferrous metals, building materials up to the depth of the location of the destroyed shafts of mine structures. In soil samples from 3 sites of silo launchers located in the Chelyabinsk region, asymmetric dimethyl-hydrazine was found in concentrations exceeding the MPC by 1.02 - 1.6 times. In water samples from open and water-flooded shafts of silo launchers, degradation products of unsymmetrical dimethyl-hydrazine were absent. Contamination of herbaceous and coniferous vegetation with asymmetric dimethyl-hydrazine at the surveyed sites has not been established. Conclusion. Soil contamination with asymmetric dimethyl-hydrazine at three remedied sites of 20 surveyed ones may be the result of their unauthorized opening. After the intrusion, the orphan sites of the silo launchers become objects of increased chemical hazard and environmental risk. Such things require carrying out nature restoration work, strengthening supervision over their technical, health and ecological condition.