Crystalline Silica IN AIR & WATER, AND HEALTH EFFECTS Crystalline silica is a type of silica formed from silica sand, a ‘building block’ material in rock, soil and sand, through natural heat and pressure. It is used in a number of industrial and commercial processes like glass-making, road-building, hydraulic fracturing for oil and gas production, water filtration, and even electronics. Who Does It Affect? Silica Sand Mining & Water Exposure to silica sand particles is of Silica sand mining or processing can affect greatest concern for workers in the fracking drinking water sources. or mining industry, and other construction trades where dust is generated. People who Groundwater live in communities near silica mining and processing operations have not been shown Any mine may create a pathway for to be exposed to levels of crystalline silica chemicals and/or bacteria to more easily harmful for health. reach the groundwater. The risks to drinking water depend on: ▪ How close the mining operations are to Silica in Air the groundwater’s surface Crystalline silica can be released into the air ▪ The use of heavy equipment from cutting, grinding, drilling, crushing, ▪ Leaks and spills of fuel, engine oil or sanding, or breaking apart many different other chemicals materials. A few years ago, concern ▪ Runoff from contaminant sources or mounted surrounding silica sand mining waste dumped illegally in the mine activities and the potential release of large Products called flocculants used by some amounts of crystalline silica into the air. In frac sand mines (mines that extract silica response, MDH developed a health-based sand to be used for hydraulic fracturing) guidance value for crystalline silica in the air may contain low concentrations of and the Minnesota Pollution Control chemicals (acrylamide and DADMAC) that Agency (MPCA) began monitoring for are of potential concern. MPCA sets limits crystalline silica in air near silica sand in the mine’s permit for the amount of facilities. Please see: MDH’s Crystalline flocculants that can be used and MDH Silica Toxicological Summary Sheet (PDF) recommends monitoring of the (https://www.health.state.mn.us/communi groundwater at facilities where the ties/environment/risk/docs/guidance/air/sil chemicals are used to ensure safe drinking icasumm.pdf) and Air monitoring at water levels are not exceeded. Minnesota silica sand facilities (https://www.pca.state.mn.us/air/air- Groundwater near frac sand mines may monitoring-minnesota-silica-sand-facilities). become slightly more acidic (lower in pH). CRYSTALLINE SILICA This may cause minerals (like iron and control exposure to workers and the manganese) to more easily dissolve, which general public. can cause water to have unpleasant taste At high concentrations in the air: and odor, and may cause staining. MDH Disease risk is related to both the levels and recommends that pH be included in the duration of crystalline silica exposure. The water monitoring list for groundwater near onset of disease may occur long after the frac sand mining operations. exposure has stopped. Silicosis, lung cancer, chronic bronchitis, and several autoimmune Wells diseases have been linked to long term or very high exposures to crystalline silica. Mining can remove large volumes of groundwater and has the potential to Health effects of crystalline silica have been impact nearby wells. Impacts could include well studied in workers. Occupational the lowering of water levels, possibly even exposures are associated with serious causing a nearby well to go dry. health effects at higher concentrations in the air, and new rules have recently been ▪ The Minnesota Department of Natural implemented to better control worker Resources reviews large water removal exposures. activities to ensure that groundwater use will not harm wells in the area. At lower concentrations in the air: We do not currently know what impacts ▪ MDH evaluates whether there are any silica has at lower concentrations such as potential risks to community water those typically found in air. At this time, supply wells. there is no evidence that exposure to low- ▪ MDH recommends a number of actions levels of breathable crystalline silica in air to prevent or reduce the potential for has adverse health effects. This continues pollutants to enter the groundwater to be an area of on-going research. and water quality monitoring to protect nearby drinking water wells. For more information about the health and environmental impacts from crystalline Health Effects silica and silica sand mining, see Crystalline Silica in Air & Water, and Health Effects Crystalline silica is a substance of concern (https://www.health.state.mn.us/communi for human health. Dust sized silica particles, ties/environment/hazardous/topics/silica.ht invisible to the naked eye, are generated ml)). during a variety of activities and can be breathed into the body where they reach deep into the lungs. Once in the lungs, Minnesota Department of Health these particles can be coughed up, or pass Site Assessment and Consultation Unit from the lungs to other organs in the body 651-201-4897 or toll-free 1-800-657-3908 through the blood stream, or stay stuck in [email protected] the lungs. Breathing crystalline silica www.health.state.mn.us repeatedly over many years is a well-known To obtain this information in a different format, call: cause of occupational health problems. 651-201-4897. Printed on recycled paper. Suppression of this dust is important to 2 3/27/2019 .