"The U.S. government is planning stricter controls on exposure to silica, a carcinogen found in workplaces ranging from dentist's offices to granite quarries, according to a new report."
"Silica is powdered quartz, in particles so small they can be inhaled deep into the lungs. The Occupational Safety and Health Administration (OSHA) estimates that 2.2 million people in the U.S. are exposed to silica at work, including 1.85 million construction workers.
Other occupations carrying a risk of silica exposure include sandblasting, mining, stone grinding, as well as ceramic and glass manufacturing. Dental assistants may be exposed if they grind silica-containing casts and porcelains."