Assessing dust concentration at the workplace of a crushing and screening plant operator for special labor conditions evaluation

The mining industry is one of the key sectors of the Russian economy, supplying other industries with essential raw materials. However, this sector is characterized by harsh working conditions that may adversely affect workers' health. Exposure to harmful substances and significant physical workloads contribute to the development of occupational diseases. To ensure safety in production processes and protect the health of mining industry workers, it is necessary to conduct a special labor conditions assessment. This assessment allows for determining the level of harmfulness and hazard in workplaces, as well as developing measures to reduce the negative impact on workers' health. The purpose of this study is to assess dust concentration at the workplace of a crushing and screening plant operator as part of a special labor conditions evaluation. Dust concentration at the operator's workplace was measured using a standard gravimetric method. The testing was conducted in four stages and lasted 400 minutes, which is 83% of the total work shift duration. Data analysis revealed an exceedance of the permissible dust concentration by a factor of 1.28. The labor conditions class (subclass) was established as 3.1. It was found that the average dust concentrations varied by a factor of 3-4 across different testing stages due to the intensity and direction of air velocity at the production site. Based on the obtained data, dust concentrations at the workplace were predicted according to air velocity at the site, with an approximation accuracy of R2 = 0.95. It was determined that the maximum allowable air velocity at the site should not exceed 2.6 m/s. Using approximated data, it was forecasted that, in the absence of air movement, the dust concentration at the operator's workplace would remain at 0.5 mg/m³. To reduce dust concentration at the operator’s workplace, comprehensive measures to minimize dust generation at the crushing plant are necessary, including washing vehicle wheels, installing dust suppression systems, and replacing the open belt conveyor with a closed one. To prevent the development of occupational diseases, operators are advised to use personal respiratory, skin, and eye protection throughout the shift.