An Evaluation of Carbon Concentrations Associted with Biodiesel Particulate Matter in an Underground Metal Mine

Exposure to diesel particulate matter from diesel exhaust has been shown to have adverse health effects in humans. In 2012 The International Agency for Research on Cancer classified diesel exhaust as a group 1 know human carcinogen. Because of the associated health effects, there has been a strong push to reduce the amount of diesel exhaust present in the mining industry. Biodiesel is one to the more common and promising control options used to reduce the amount of diesel particulate matter that is generated during fuel combustion. The use of biodiesel over petroleum diesel has been shown to reduce not only particulate matter, but hydro carbon and carbon monoxide mass emissions as well. Personal and area samples were collected at an underground metal mine in the northwestern United States to evaluate the current blend of B70 biodiesel. The objective of this research was to evaluate the carbon levels associated with diesel particulate matter generated from the combustion of a B70 biodiesel. Data was also compared to past studies on which diesel particulate matter from petroleum diesel was evaluated. Samples were taken on four separate four day campaigns between March and October of 2014. Area samples were taken from 7 different areas in the mine and personal samples were taken from a 20 person cohort. The equipment used for sampling was compliant with the NIOSH 5040 method. Statistical analysis of the results was done using Minitab 17 software. The statistical analysis showed that the total carbon concentrations from biodiesel were well below the MSHA exposure limit. Results also showed that organic/elemental carbon ratios were consistent with past studies as the concentrations of organic carbon were significantly higher than those of elemental carbon.

Impact of a Changing Climate on Fine Particulate Concentrations in Butte, MT

A model was developed to assess the potential change in PM2.5 concentrations in Butte, Montana over the course of the 21st century as the result of climate change and changes in emissions. The EPA AERMOD regulatory model was run using NARCCAP climate data for the years of 2040, 2050, 2060 and 2070, and the results were compared to the NAAQS to determine if there is the potential for future impacts to human health. This model predicted an average annual concentration of 15.84 µg/m3 in the year 2050, which would exceed the primary NAAQS of 12 µg/m3 and is a large increase over the average concentration from 2010 – 2012 of 10.52 µg/m3. The effectiveness of a wood stove change out program was also evaluated to determine its efficacy, and modeled results predicted that by changing out 100% of inefficient stoves with an EPA approved model, concentrations could be reduced below the NAAQS.