Asked in Poisons and ToxinsIgneous Rock
Is Granite toxic?
August 23, 2008 4:00AM
Yes, very much so! There are three main dangers, dust ingestion, dust inhalation, and heavy metal leaching caused by acidic food or drink. Granite contains Polonium, Lead, Plutonium, Uranium, and Thalium. Other heavy metals like Arsenic, Mercury, Tungsten, Cadiumand Vanadium are also present. The dust ingestion could come from allowing a fabricator to grind or cut inside the home, a common practice on cut outs in fragile stones. Also minute particles, smaller than what we would normally call dust, can flake off some stones. Many consumers complain of a grittty feel to some tops, something that putting a heavy seal coat will reduce but not eliminate. Fabricators are at most risk for dust ingestion but homeowners should not place food, roll dough or use granite as a cutting board. Dust inhalation can come from the same sources as ingested dust. Again fabricators are most at risk but homeowners are not risk free. Heavy metal leaching is by far the worst danger. Granite contains three main sources of both heavy metals and radiation, Potassium 40, Thorium, and Uranium. Keep in mind that all three of these elements are unstable, they do decay constantly into other elements. Thoruim is more of a danger to fabrictors than homeowners, if aerosolized or present in dust form, it can lead to increased risk of cancers of the lungs, pancreas, and blood. (I didn't know that blood can develop cancer til I looked it up!) If ingested, there is an increased risk of liver diseases. Here is a link to a decay chain article, look up the thorium decay chain. I counted 13 Alpha decays and 7 Beta decay, for a total of 20 radioactive particles emitted per atom of Thoruim present. The long half lives don't matter, some are decaying at all times. Note that many of the steps in the decay chain are toxic heavy metals, Polonium, Plutonium (yes, that Plutonium), Uranium, Thallium, and Lead. The rest of the steps are just radioactive! Granite has more poisonous substances in it than any other countertop material, by far. So don't lick the granite! Al