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Air quality & crystalline silica (additional information)

Air quality: particulate matter

Within the state of Illinois the Illinois Environmental Protection Agency is required by the federal Clean Air Act1, to identify areas of the state that are not meeting ambient air quality standards and determine, with the approval of the United States Environmental Protection Agency (USEPA), a plan for improving air quality to meet the federal standards through regulations, approved orders requiring pollution control, and planning documents. This plan is called a State Implementation Plan (SIP). The Illinois SIP can be found at the following link: 

La Salle County is located in an air quality attainment area, and in compliance with the Federal Clean Air Act.1 There are a number of known and monitored sources of Particulate Matter (PM) at the PM2.5 and PM10 levels in the County including agriculture, dust, fires, fuel consumption, industrial processes, mobile, solvent and miscellaneous. PM2.5 and PM10 are considered inhalable particles.2
According to the USEPA, using the most recent National Emission Inventory Data from 2011, all sources (agriculture, dust, fires, fuel consumption, industrial processes, mobile, solvent and miscellaneous) within La Salle County produced 3,703 Tons of PM2.5. All Industrial Processes, of which mining is a subcategory, in La Salle County produced 453 Tons, or 12.2% of all PM2.5 produced. However, mining produced zero (0) Tons of PM2.5, according to the US EPA.3

National Emission Inventory Data from 2011 (most recent) indicate all sources (agriculture, dust, fires, fuel consumption, industrial processes, mobile, solvent and miscellaneous) within La Salle County produced 16,149 tons of Particulate Matter at the PM10 level. Industrial Processes (of which Mining is a subcategory) accounted for just 799 tons or 4.9% of all PM10 produced. Of this amount less than one (1) ton is attributed to mining processes.4

1. (USEPA. Green Book. Accessed 10/24/2014)
2. (USEPA. Particle Matter: Basic Information. Accessed 10/24/2014)
3. (USEPA. Air Emission Sources: Particulate Matter. Accessed 10/24/2014)
4. (USEPA. Air Emission Sources: Particulate Matter. Accessed 10/24/2014).

Crystalline silica

In 1996, the USEPA published a review of the data concerning “ambient” crystalline silica levels. Ambient crystalline silica levels are those outside of a work place; that is, the levels of crystalline silica in the air outside of the property of a plant, quarry or any other work site. The USEPA reported that ambient crystalline silica levels in the United States are up to 8 µg/m3 (micrograms per cubic meter), and estimated an average ambient silica level (measured as PM10) in urban areas of 1.9 µg/m3, with a range of 0.8 to 5.0 µg/m3. Based on the available particulate matter data, the U.S. EPA concluded that: (1) about 90% of ambient crystalline silica comes from fugitive dust sources, and (2) the largest fugitive dust sources are unpaved roads, paved roads, construction and agricultural tillage. The USEPA concluded that mining and quarrying contribute only 1% of the ambient dust, roughly 15 times less than agriculture.5

While there is no evidence that ambient exposures to crystalline silica at levels present in the United States cause illness or disease, it is well established that occupational exposure to crystalline silica can cause the occupational disease silicosis and other diseases. Silicosis can occur after prolonged exposure to respirable crystalline silica at levels above the Permissible Expose Level (PEL) set by the United States Occupational Safety and Health Administration (OSHA), which regulates general industry and construction, and the United States Mine Safety Health Administration (MSHA), which regulates mining. The permissible exposure level established by OSHA and MSHA is a formula (10 ÷ %silica+2), which approximately equals 100 µg/m3.6 Mine operators in La Salle County are committed to working with OSHA and MSHA to ensure their employees are not exposed to dust and silica that exceed the PEL.

5. (U.S. EPA. Health Effects of Inhaled Crystalline and Amorphous Silica. U.S. Environmental Protection Agency, Office of Research and Development, National Center For Environmental Assessment, Research Triangle Park Office, Research Triangle Park, NC, EPA/600/R-95/115, 1996).
6. (Wisconsin Industrial Sand Association. Crystalline Silica May 2013. Accessed 10/21/2014).

More information about the environmental impacts of silica sand mining can be found in the report below by Isaac Orr and Mark Krumenacher as well as a comprehensive review of regulatory control and oversight of industrial sand mining.
Shawn McKinney,
Apr 3, 2017, 7:39 AM