Study on dust exposure levels and respiratory particle deposition patterns of workers in respirable dust environments

Quantifying the deposition of respirable dust in the respiratory tract under coal mining production conditions is essential for effectively improving industrial dust control technologies and developing occupational protective equipment. This study designed a series of test experiments to investigate dust exposure, with a focus on the impact of inhalable dust dispersion on the respiratory tracts of workers. The overall study encompassed three main components: the setup of respiratory parameters, fluorescence tracing experiments, and particle deposition tests in the respiratory tract. The validation of the experiments was carried out using bidirectional coupling simulations based on CFD-DEM. The study tested the performance of common dust-proof masks in coal mining using an occupational disease detection platform. The results indicate that the overall particle deposition is highest in the lobar bronchi, with the deposition rate in the right lobar bronchi showing the most significant variation with particle size. For particles smaller than 10 μm depositing in the respiratory tract, inertial impaction is the dominant factor. This phenomenon becomes more pronounced with increasing breathing intensity. The increase in flow velocity facilitates the dispersion and dilution of particles. The deposition rate of 1 μm particles is hardly influenced by breathing intensity. For particles smaller than 5 μm, the escape rate exceeds 90 %.