What is the health and safety problem? Exposure to elevated diesel exhaust concentrations has been linked to negative health effects such as eye and nose irritation, headaches, nausea, and asthma. Diesel particulate matter (DPM) has been classified as a possible carcinogen by both the National Institute for Occupational Safety and Health (NIOSH) and the Environmental Protection Agency (EPA). Diesel engines are a major contributor to elevated concentrations of carbon monoxide, carbon dioxide, oxides of nitrogen, and hydrocarbons in underground coal and metal/nonmetal mines. What is the extent of the problem? Currently, underground miners can be exposed to more than 100 times the typical environmental concentration of diesel exhaust and more than 10 times what might be found in other workplaces. As mines add more and more pieces of diesel equipment the potential overexposure becomes an even greater risk. How is OMSHR addressing the problem? The Office of Mine Safety and Health Research (OMSHR) is working to reduce respiratory diseases in miners associated with diesel emissions by reducing miners' exposure to these emissions in underground mines. This goal is addressed by evaluating methods to control emissions from diesel equipment and by developing new monitoring techniques that identify exposure limits in order to reduce potential overexposures. What are the significant findings? OMSHR research has resulted in a method to continuously monitor personal exposure to diesel particulate matter in underground mines. This monitoring device has been licensed and is currently being sold commercially. In addition, OMSHR research has evaluated numerous control technologies to reduce emissions from diesel equipment. Evaluated control technologies include diesel particulate filters, alternative fuels (biodiesel), emissions-assisted maintenance programs, and fuel additives. What are the next steps? The OMSHR diesel research group will continue both laboratory and field evaluations of novel and emerging technologies to control diesel emissions including modern engines, exhaust aftertreatment technologies, and alternative fuels. In addition, OMSHR researchers will continue research on the properties of aerosols emitted by diesel engines and aftertreatment systems. The work in this topic area is supported by the NIOSH Mining Diesel Monitoring and Control program. See the NIOSH Mining Products page for software, guides, training materials or other items related to this topic.

Tools and Resources

Guides

Diesel Aerosols and Gases in Underground Mines: Guide to Exposure Assessment and Control (PDF, 2414 KB, 2011)
A comprehensive guide to establish a program to curtail diesel particulate matter emissions, control pollutants after release in an underground mine environment and reduce exposures using administrative controls.

Measurement & analysis

Evaluation of the SKC® DPM Cassette for Monitoring Diesel Particulate Matter in Coal Mines (PDF, 347 KB, 2004-12)
A commercial version of the BOM impactor, called the DPM Cassette, was recently introduced by SKC®. Tests were conducted to evaluate the performance of the DPM Cassette for measuring diesel-source elemental carbon in the presence of coal dust.

Relationship Between Elemental Carbon, Total Carbon, and Diesel Particulate Matter in Several Underground Metal/nonmetal Mines (PDF, 526 KB, 2007)
Elemental carbon (EC) is currently used as a surrogate for diesel particulate matter (DPM) in underground mines since it can be accurately measured at low concentrations and diesels are the only source of submicrometer EC in underground mines. A disadvantage of using EC as a surrogate for DPM is that the fraction of EC in DPM is a function of various engine parameters and fuel formulations, etc. In order to evaluate how EC predicts DPM in the underground mining atmosphere, measurements of total carbon (TC; representing over 80% of the DPM) and EC were taken away from potential interferences in four underground metal/non-metal mines during actual production. In a controlled atmosphere, DPM mass, TIC, and EC measurements were also collected while several different types of vehicles simulated production with and without different types of control technologies.

Engineering controls

Aerosols Emitted in Underground Mine Air by Diesel Engine Fueled with Biodiesel (PDF, 239 KB, 2010-02)
The results of this study provide more insight into potential advantages and disadvantages of using biodiesel fuels for controlling emissions of aerosols and gases. The role of diesel oxidation catalysts in controlling biodiesel emissions has also been re-examined.

Effectiveness of Selected Diesel Particulate Matter Control Technologies for Underground Mining Applications: Isolated Zone Study, 2003 (PDF, 1247 KB, 2006-05)
A study was conducted in an underground metal mine to assess the effects of selected diesel emissions control technologies on concentrations of diesel particulate matter and gases in underground mine air. The control technologies included diesel particulate filter (DPF) systems, filtration system with disposable filter elements, diesel oxidation catalytic converter, and biodiesel blends.

Effectiveness of Selected Diesel Particulate Matter Control Technologies for Underground Mining Applications: Isolated Zone Study, 2004 (PDF, 1146 KB, 2006-08)
This study evaluated the effectiveness of the state-of-the-art technologies for controlling DPM and gaseous emissions from underground diesel-powered mining equipment using the isolated zone approach.

Effects of Diesel Exhaust Aftertreatment Devices on Concentrations and Size Distribution of Aerosols in Underground Mine Air (PDF, 227 KB, 2009-09)
This paper summarizes the results of a study conducted to evaluate the effects that several types of DPFs, DFEs, and a DOC have on the concentration and size distribution of diesel aerosols in an underground mine.