ABSTRACT
We report the first spectral photoacoustic measurements of silica, coal, and kaolinite dust absorption coefficients from 11 μm to 13 μm at 5 nm resolution made with a tunable quantum cascade laser. This is important because airborne silica dust and coal dust within mining environments continue to be a problem for mine workers and staff due to their severe health effects on the respiratory system, while other dust types are interferents. Our real-time spectra compare favorably with the filter-based Fourier Transform Infrared Spectrometer (FTIR) spectra obtained using the sampling system developed by NIOSH for their end-of-shift method to determine silica dust concentrations using a portable FTIR. We discuss our new dust generation system and instrument testing chamber. We also show that our PM4 silica mass concentration measurements by a low-cost air quality sensor (SPS30) are in good agreement with the TSI Aerosol Particle Sizer instrument and the NIOSH end of shift method.
