# An Assessment of the Impact of Gypsum Deposit Development on Changes in the Radiation Environment
## 1 Introduction  
Mining operations involve the extraction of huge masses of rock and soil to the surface. In addition to significant changes in the morphology of the territory, this also leads to changes in the distribution of chemical elements and radionuclides in the environment. First of all, the quality of water and bottom sediments in nearby watercourses and reservoirs suffers due to the discharge of quarry waters, as well as the soil cover due to aero-technogenic pollution [1, 2]. The Glubokoye gypsum deposit is located in the northern taiga zone in northwestern Russia. It has been developed since 2008. The annual extraction of gypsum rock averages 600 thousand tons. Gypsum rock is mined by using the quarry method with blasting operations. It is generally recognized that the open-pit development of bedded deposits has the most significant impact on the environment. The extraction of gypsum is accompanied by a number of successive operations, including deforestation on part of the license area, the excavation of the layer of quaternary deposits lying above the gypsum rocks, blasting operations, the movement of gypsum using excavators and loaders, the crushing of gypsum using a crushing and sorting plant, the transportation of gypsum rock and overburden rocks and the storage of finished products. A complicating factor is the location of the quarry, two hundred meters from the State Natural Landscape Reserve ofRegional Significance \"Chugsky\". It was created to preserve the unique Chug relief, which is characterized by a large area of exposure of the gypsum basement under the influence of glacial exaration, the presence of large formations of dissected preglacial relief, small thickness of the Quaternary sediment cover and a hydrographic network with canyon- or trough-shaped valleys [3,4]. As a result, unique forms such as shelopnyakovye fields, collapsed cliques and ravines, disappearing lakes, towers and caves are widely represented on the territory of the Chugsky Reserve. The specificity of the lithogenic basis of ecosystems at dense gypsum outcrops, which determines the structure and geochemistry of the soil cover, vegetation and natural waters, made it possible to identify a new sulfate-calcium geochemical class in the family of northern taiga landscapes [5]. The four largest caves of the Chugsky Natural Reserve are included in the Cadastre of Large Gypsum Caves of the World and are worthy of being declared natural monuments [6]. The territory of the reserve contains habitats of rare and protected epiphytic lichens and coprophilous mosses, as well as protected animal species such as the ospyre (_Pandion haliaetus_), the peergrine falcon (_Falco peergirus_), the eagle owl (_Bubo bubo_) and the great grey shrike (_Larius excubitor_) [7]. Previously, we studied the features of chemical pollution of the environment during the development of gypsum deposits with an assessment of pollution sources and transfer rates [8]. The aim of this study was to assess the impact of gypsum deposit development on changes in the radiation environment. The relevance of such a study is associated, in particular, with the high radon hazard of cave complexes widely visited by tourists [9, 10, 11]. Radon and its short-lived decay products pose a health hazard due to their carcinogenic effects. The radiation safety standards of the Russian Federation establish limits for the radon flux density (RFD) on land plots before construction--80 and 250 mBq (m\({}^{2}\)s)\({}^{-1}\) for residential/public buildings and industrial buildings, respectively. With such RFD values, the values of the equivalent equilibrium radon concentration (EERC), which is used instead of the specific radon activity (SAR) in Russia, are 100 and 300 Bq m\({}^{-3}\), respectively [12]. In some cases, caves have been found to exceed the permissible levels for the population and workers by 100 to 500 times [13, 14, 15, 16].