Mining Project: Control Technologies and Strategies for Reducing Exposure of Underground Miners to Diesel Emissions

Research Summary

In recent years, health effects associted with exposure to diesel particulate matter (DPM) and other combustion-generated nanometer and ultrafine aerosols have received substantial attention. Diesel engines, which are widely used to power vehicles and equipment in mining, trucking, and many other industries, were found to be a major source of workers' exposure to nanometer and ultrafine aerosols.

This project evaluated and aimed to implement the current and emerging control technologies and strategies that are used to reduce the exposure of workers to DPM. The physical, chemical, and toxicologocial properties of DPM were characterized through a series of engine/dnynamometer tests at the NIOSH Diesel Laboratory and through a series of isolated zone studies in production mines. As part of the technology transfer, some of the evaluated technologies and strategies were implemented in participating mines and evaluated over an extended period of time.

The research aims of this project were:

• Evaluation of exhaust aftertreatment systems designed for particulate emissions control such as diesel particulate filter (DPF) systems and flow through filters (FTFs), and the systems for control of gaseous emissions such as diesel oxidation catalyst (DOC) and selective catalyst reduction (SCR).
• Evaluation of filtration systems used on enclosed cabs, with the emphasis given to the efficiency of those systems that remove DPM from the mine air. The potential for reducing NO₂ concentrations was also examined. 
• Evaluation of alternative fuels such as biodiesel and potentially gas-to-liquid synthetic diesel.
• Detailed physical and chemical characterization and speciation of diesel aerosols collected during laboratory and field studies.
• Examination of metrics for monitoring exposure to diesel aerosols.
• Assistance to the underground mining industry in the selection and implementation of these technologies and strategies.

The knowledge obtained in this study will help in reducing the exposure of underground miners to diesel aerosols via implementation and greater acceptance of advanced diesel emissions control technologies, education on advanced strategies, and greater knowledge on the health implications related to exposure to DPM.