Crystalline silica causes cancer. More specifically, crystalline silica dust is listed by both the World Health Organization and the U.S. National Toxicology Program as a known human lung carcinogen. Unlike tobacco smoke, silica dust does not provoke tumors via genetic mutations. Instead, its method of injury is to trigger inflammation and suppress immune functioning. It also causes silicosis, a disabling and sometimes fatal condition in which fibrous nodules fill the spongy pulmonary chambers, prompting infections and heart failure. For both reasons, crystalline silica is regulated by the Occupational Safety and Health Administration. There are legal limits to how much silica dust a person operating a sandblaster can inhale.
Before midwestern sand counties were turned inside out—and towering, windblown dunes of powdery silica began appearing within view of people’s kitchen windows—the general public was not thought to suffer appreciable exposures. There are thus no standards for us. No research program has ever addressed the possible impact of silica dust on, say, pregnancy outcome or the lung development of children. Lack of study on public health effects means that the occupational carcinogen crystalline silica is not regulated as a hazardous air pollutant. At least not in Wisconsin and not at this writing.
A SAND COUNTY ALMANAC was published in 1949. In the same year, an oil-field service company called Halliburton fracked its first commercial well and so ushered in a new method for extracting oil and gas by using pressure, water, chemicals, and sand to blow up shale. The function of the sand is to hold the stone doors ajar so that the hydrocarbons can flow out and up.
But the shale boom didn’t really take off until 2005, the year that fracking received exemptions from most major federal environmental regulations (the now-famous “Halliburton loophole”). By 2008, Wisconsin sand had become a highly prized quarry. The Samson of silica, its grains were the ideal size, shape, and strength for propping open cracks a mile or more below the earth’s surface. And that’s how the nation’s Devonian bedrock became the new destination spot for Sand County. That’s how Aldo Leopold’s farm in central Wisconsin could end up fracking Rachel Carson’s childhood home on the Marcellus shale of western Pennsylvania.
In 2009, the last year for which data are available, 6.5 million tons of U.S. sand were mined, washed, processed, loaded onto trucks and trains, carried to wellheads, and shot into the center of the earth. Six and a half million tons is the approximate weight of the Great Pyramid of Giza. According to commodities analysts, that figure probably doubled in 2010 and likely doubled again last year.
http://www.orionmagazine.org/index.php/articles/article/6811