We address the potential health effects of crystalline silica from gravel mining on our Health page. According to Resolution 98-32, which conditionally approves Boulder County Land Use Docket SU-96-18, loading and hauling operations will cease when sustained wind speeds exceed 30 MPH, but crushing, conveying, and drilling operations may continue. How much crystalline silica do these latter activities release into the atmosphere? Given the presence of quartz in the gravels and sand of the St. Vrain floodplain; the downwind proximity of schools, residents, and animals to the proposed mining site; and new scientific knowledge about the dire health effects of crystalline silica; we call for better data on the effects of crystalline silica upon communities and ecosystems in the proximity of gravel mines.
In their 2015 article, “Assessment of Community Exposure to Ambient Respirable Crystalline Silica near Frac Sand Processing Facilities” [PDF], John Richards and Todd Brozell state, “Additional sampling is needed to evaluate respirable crystalline silica concentrations at the fence lines of other industrial, agricultural, and community sources. More long-term average concentration data are needed concerning the seasonal variability of background concentrations, especially in arid areas subject to wind entrainment of crystalline silica containing soil” (978). Before potentially putting the safety of so many in jeopardy, we need more solid scientific data about the crystalline silica found in fugitive dust from gravel mining site preparation, aggregate excavation, and aggregate processing and handling–including what concentration levels are carried downwind at which wind speeds and how far. This is especially important in our area, where wind direction is variable and sustained wind speeds frequently exceed 30 MPH. For those living in the vicinity of the proposed mining operation, the duration of exposure to fugitive dust would be greater than it is to those living farther away. Community members have the right to information about hazardous particles in the air we breathe, and agency in the decision-making process about industrial activities that may affect our health.