Slovakia has a long tradition in mining of iron ores, non-ferrous metals and magnesite. In addition to mining and raw material processing technologies, the environmental issues, especially the work subsystem environment, have been actively researched. The mining activity is generally connected with a high work risk rate. In the environment of mine, as well as during raw material processing it comes to the formation of harmful substances of which the solid mineral dust represents a dominant risk. Such a dust dispersed in air is called an aerosol. Dust and other components dispersed in the mine air medium produced within the technological mining and raw material processing and natural rock massive emanations, create the mine aerosol. Quartz is considered as the most dangerous mineral. If inhaled for a long period of time, it causes the incurable disease - pneumo-coniosis - silicosis. If quartz and other silicate minerals dominate in the dust deposited in the pulmonary organ, they cause fibrosis. The study of properties of quartz and quartz-like minerals enabled to evaluate the rate of risk in the individual mines. The experiments were carried out with various kinds of quartz and other minerals often occurring in the Slovak mines. A significant fact about the quartz was observed - the rate of fibrogenity is connected with the genetic properties of quartz. From the point of view of fibrogenity, the grain size and certain size class, which is often reposited in the pulmonary organ, also represent an important issue. The classes, representing a maximum fibrogenic effect have been determined. It is the case of particles of respirable character (< 5 µm), mainly those in the class range of 1 – 3 µm. These particles can get into the interstitium of lungs, initiating a creation of fibrogenic tissues. The movement of mineral individuals and their abidance in the mine air medium and mine aerosol is influenced by basic properties, which have been determined under simulated conditions and confirmed by in-situ measurements. These properties are shape, size, specific weight, as well as the properties of dispersion environment like humidity, flow, temperature, and, in particular conditions, the shape and profile of mine.The risk of mine aerosols has been studied in Slovak mines, while the research has been focused on those, operating before 1990. The following values have been determined: risk of dustiness R, specific harmfulness ša of a cumulative dose of dust KDc, factor of fibrogenic effect of dust Mf, respirable ration of dust D, percentual ratio of quartz Q and the determination of the highest admissible concentration of dust on the particular workplace NPKc. On the basis of this study it was possible to determine the degree of risk in individual localities and to search possibilities of the dust prevention. It has been recommended to apply the method influencing the fibrogenic effects of dust before it penetrates the pulmonary organ - the use of hydroxide-aluminium compound in the washing and spraying water.The presented evaluation of dustiness risk and its prevention is not currently a topic of great significance due to the recession of the mining industry. Certain revival is expected in the construction of tunnels in connection with the planned project of construction of roads, when the mining works are required.