Mining Project: Advanced Strategies for Controlling Exposures to Diesel Aerosols

Research Summary

Diesel-powered equipment is extensively used in the underground mining industry in the United States. Over 5,000 diesel engines provide power to various equipment in 185 underground coal mines, and approximately 7,700 diesel-powered units are deployed in 177 underground metal and nonmetal mines. As a result, approximately 15,000 underground coal miners and 13,000 underground metal/nonmetal miners in the U.S. are exposed to aerosols and gases emitted by diesel engines, and exposure of underground miners to diesel aerosols is the highest among workers in all occupations. Exposure to diesel exhaust is also linked to various adverse health outcomes. Long-term exposure to combustion-related fine particulate pollution is perceived as an important risk factor for cardiovascular and lung cancer mortality, and in 2012, the International Agency for Research on Cancer (IARC) categorized diesel engine exhaust as a carcinogen to humans (Group 1).

Extensive efforts on the part of industry and government have resulted in dramatic reductions in the average exposure levels of underground miners to diesel particulate matter (DPM). However, additional efforts are needed to further reduce exposures that, according to the compliance data gathered by the Mine Safety and Health Administration (MSHA), frequently exceed the current MSHA permissible exposure limit (PEL) of 160 µg/m³. Engineering and other solutions are particularly needed to address issues specific to a variety of duties and tasks performed in challenging underground mining environments.

Through the development, evaluation, and demonstration of an array of underground-mining-viable advanced control strategies and technologies, this project research provided the industry with a number of necessary tools to significantly reduce miners’ exposures to diesel aerosols and gases.

The four research aims of this project were as follows:

1. To develop and evaluate technologies and strategies to prevent overexposures to DPM of critically affected occupations in underground metal and nonmetal mining operations.
2. To evaluate, in both the laboratory and the field, novel and emerging advanced engine technologies for heavy-duty (HD) and light-duty (LD) underground mining applications.
3. To develop and evaluate environmental enclosures and filtration systems for mobile underground mining equipment as a control strategy for diesel aerosols.
4. To develop and evaluate canopy air curtains for mobile underground mining equipment as a control strategy for diesel aerosols.

This project produced several peer-reviewed, conference, and other publications on the topics related to the research aims outlined above. The presentations were given at various national and international conferences.  One-day diesel workshops and short courses were provided at the North American Mine Ventilation Symposiums and the International Mine Ventilation Congress.

The adoption and implementation of control technologies and strategies evaluated in this project helped industry in its efforts to substantially reduce average exposure levels and the number of overexposures of underground workers in selected underground metal and nonmetal mines, and to support an increase in the use of advancement engines and exhaust aftertreatment devices and environmental enclosures in underground coal, metal, and nonmetal mining industries.

Related Presentations and Publications

Mischler S, Lee T, Vanderslice S [2024]. Canopy air curtain to reduce diesel particulate matter exposure underground blasters. Proceedings of the MINEXCHANGE 2024 SME Annual Conference & Expo, Feb 25–28, Phoenix, AZ (Accepted).

Bugarski AD, Stachulak J [2023]. Road map toward DPM-free and decarbonized underground mines. Workshop at the 19th North American Mine Ventilation Symposium (NAMVS 2023), June 18, 2023, Rapid City, South Dakota.

Bugarski AD [2023]. Holistic approach toward controlling exposure of underground miners to particulate matter and gases emitted by diesel-powered equipment. Sibanye Stillwater East Boulder Mine, April 10–14, 2023, Big Timber, Montana.

Bugarski AD, Barone TL, Hummer JA, Lee T, Vanderslice S, Friend S [2023]. Improvement of size-selective sampling of diesel aerosols in underground mines. Tukkaraja P (Ed.): Proceedings of the 19^th North American Mine Ventilation Symposium (NAMVS 2023), June 17–22, 2023, Rapid City, South Dakota, USA.

Habibi A, Bugarski AD, Loring D, Cable A, Ingalls L, Rutter C [2023]. Evaluation of methodology for real-time monitoring of diesel particulate matter in underground mines. Min Metal Explor 40:453–461.

Bugarski AD, Vanderslice S, Hummer JA, Barone TL, Mischler SE, Peters S, Cochrane S, Winkler J [2022]. Diesel aerosols in an underground coal mine. Min Metal Explor 39:937–945.

Bugarski AD, Hummer JA, Vanderslice S, Shahan MR [2020]. Characterization of aerosols in an underground mine during a longwall move. Min Metal Explor 37:1065–1078.

Bugarski AD, Barone TL, Hummer JA [2020]. Diesel and welding aerosols in an underground mine. Int J Min Sci Tech 30:449–454.

Noll JD, Bugarski AD, Vanderslice S, Hummer JA [2020]. High-sensitivity cassette for occupational sampling of diesel particulate matter. Env Mon Ass 192(6):333.

Bugarski AD, Hummer JA, Vanderslice S, Barone T [2020]. Retrofitting and repowering as control strategies for the curtailment of exposure of underground miners to diesel aerosols. J Min Met Explor 37(2):791–802.

Bugarski AD, Hummer JA, Vanderslice S, Mischler S [2020]. Contribution of various types and categories of diesel-powered vehicles to aerosols in an underground mine. J Occup Environ Hyg 17:121–134.

Bugarski AD [2019]. Integrated approach toward reducing exposure of underground miners to diesel aerosols and gases. Workshop on Control Strategies for Curtailment of Diesel Aerosols and Gases in Underground Mines. 17^th North American Mine Ventilation Symposium (NAMVS 2019). Montreal, Quebec, Canada, April 28.

Bugarski AD [2019]. Curtailment of contribution of light-duty and medium-duty diesel-powered vehicles to exposure of underground miners to DPM: Burden, challenges, and opportunities. The Mine Safety and Health Administration (MSHA) / National Institute for Occupational Safety and Health (NIOSH) Diesel Health Effects Partnership Meeting, Washington D.C.

Bugarski AD [2018]. Diesel particulate matter: Exposures and control strategies and technologies. Workshop at 11^th International Mine Ventilation Congress, Xi'an, China, September 15.

Bugarski AD, Hummer JA, Vanderslice SE [2017]. Effects of FAME biodiesel and HVORD on emissions from an older technology diesel engine. Min Eng 69(12):43–49. 

Bugarski AD, Hummer JA, Miller A, Patts LD, Cauda AG, Stachulak JS [2016]. Emissions from a diesel engine using Fe-based fuel additives and sintered metal filtration system. Ann Occup Hyg 60(2):252–62.

Yanamala N, Hatfield MK, Farcas MT, Schwegler-Berry D, Hummer JA, Shurin MR, Birch ME, Gutkin DW, Kisin E, Kagan VE,  Bugarski AD, Shvedova AA [2013]. Biodiesel versus diesel exposure: Enhanced pulmonary inflammation, oxidative stress, and differential morphological changes in the mouse lung. Tox Appl Pharm 272:373–383.