Radioactive granite countertops are a concern for homeowners. However, the greater health concern is radioactive granite dust inhaled by fabricators. Granite fabricators can be exposed to considerably more radiation than nuclear power plant workers.



Isaac Wolf (Scripps Howard News Service) interviewed the major players in debate. The story began when San Jose industrial hygienist Linda Kincaid collected samples of airborne dust in a granite fabrication shop. The granite used for the test was radioactive Jupurana Bordeaux removed from a San Carlos home.



The air samples contained more uranium dust than is allowed in workplaces. However, uranium toxicity is not the whole story.



Granite dust emits alpha particles, a form of radiation that is especially harmful to the delicate tissue of the lung. Alpha particles do not pass through skin, so they are not harmful if they are kept outside the body.



Internally, alpha radiation is extremely damaging. Alpha particles are twenty times more damaging than beta particles or gamma rays. Damage from alpha particles can lead to lung cancer.



Health Physicist Dave Berhart calculated that granite workers could be exposed to more than 3,000 times the radiation exposure that is allowed for members of the public. Bernhart estimates that half of the granite fabricators in the county could receive a radiation dose greater than allowed by the Nuclear Regulatory Commission.



The Marble Institute of America denied that granite workers could be at risk. For decades, they have denied that granite can be excessively radioactive. Now they claim that granite fabrication shops use advanced techniques to minimize exposure to dust.



However, OSHA and Cal/OSHA view the situation differently. OSHA inspectors visited 133 granite shops in a recent one-year period. Those 133 inspections resulted in 239 citations for respiratory violations or airborne contaminants. A Labor Department spokesperson stated, “There are a significant number of facilities that continue to operate with no or inadequate engineering controls.”



Cal/OSHA found similar conditions in California granite shops. Between 2001 and 2008, 40% of granite shops violated regulations on airborne dust.



Granite fabricator Al Gerhart estimates about 5% of granite is more radioactive than a homeowner would want in a home. Physicists studying granite agree with that estimate. Data on radioactive granite will be presented by a number of scientists at a conference later this month.