Particulate Air Quality Around Wisconsin Silica Sand Mines

Abstract

The act of mining and processing quartz for hydraulic fracturing generates particulate matter (PM), as well as crystalline and amorphous silica through blasting, loading, and hauling; processing activities such as crushing; and the transportation of processed and waste sand. The purpose of our research is to quantify the risk of ambient exposure to airborne particulates around industrial silica sand operations. In past work, EPA-certified dichotomous samplers were calibrated before and after sampling, and pre and post filter weights recorded. Over a two-year period, we observed increases in average PM2.5 concentrations of 2.6 and 16.1 ug/m3 over concurrent DNR background levels near industrial sites in Bloomer and New Auburn, WI, respectively. Using published studies, we estimate this increase in PM2.5 exposure to cause a loss of life expectancy of one day per year of exposure in Bloomer and three days in New Auburn. In Albertville, WI, we conducted yearlong background air quality monitoring where mining operations are planned to begin. Here we found average PM2.5 concentrations of 11.8 ug/m3 using our EPA-certified dichotomous sampler and 15.0 ug/m3 using a spectroscopy based DustTrak II monitor. Collaborating with the DNR, industry representatives, academic colleagues, and community organizations such as Save the Hills Foundation, future research will include the use of affordable PurpleAir monitors to quantify particulate exposure using corrected formulas derived from the California South Coast Air Quality Monitoring District. In doing so, we strive to provide object information about air quality in Wisconsin, and in Sierra Leone where a monitor was recently installed next to an iron ore mine, in hopes of empowering individuals, communities, and underrepresented minorities.