This information was prepared for you
to distribute to your customers and others who have questions
or concerns about the radon and granite issue. It is copyrighted
by the Marble Institute of America, but may be reproduced,
with credit given to the Marble Institute of America.
Solid Surface,
The Journal of the Solid Surface Industry (Volume 1 Number
1) that was published several weeks ago, included an article
entitled "Granite & Radon". The introduction
to the article stated "Scientific research poses disturbing
questions about the safety of granite countertops" and
copies of this article have circulated around the stone industry
raising questions about radon gas emissions from granite countertops.
The key advertisers in this journal were Corian and Formica.
The MIA has called
upon several of the country's leading scientists in geology
and geochemistry to assist in preparing a response to the
allegations in this article that radon gas emissions from
granite countertops may be hazardous. On reading the article,
our consultants reacted with such comments as "ludicrous",
"a fabulous collage of nonsense", "politically
motivated", "unethical", and "bizarre".
Donald Langmuir, PhD,
Professor Emeritus of Chemistry and Geochemistry at the Colorado
School of Mines and President of Hydrochemical Systems Corp.,
both in Golden, Colorado, has prepared a response
on behalf of the Marble Institute of America that evaluates
and refutes these allegations. His report appears in full
in this Special Bulletin. Dr. Langmuir received his BA (with
honors), and his MA and PhD degrees in geochemistry from Harvard
University. He served as a geochemist with the Ground Water
Branch of the U.S. Geological Survey's Water Resources Division
and subsequently taught and conducted research for 11 years
at Pennsylvania State University, with temporary appointments
at Rutgers University, the Nevada Desert Research Institute,
and the University of Sydney, Australia. Dr. Langmuir has
been a full professor at the Colorado School of Mines since
1978.
In addition to working
with Dr. Langmuir and other scientists, the MIA staff also
talked with the major U.S. granite quarriers and producers
about the issue of radon emissions from granite. These companies
have certainly not ignored the issue and several have had
radon testing performed on their granites. The research done
for these companies have shown that actual levels of radon
gas emissions from granites are so low as to be insignificant
and generally represent no threat to the health and well-being
of people who live or work in buildings with granite countertops,
floor or wall tiles, furniture or any other furnishings made
from granite.
Marbles, limestones
and stones other than granites are of such mineral composition
that they generally do not contain measurable quantities of
radon-producing material. In terms of building materials,
radon emissions from concrete, cement and gypsum could be
of greater concern.
What is Radon?
Radon is a naturally occurring gas generated by the decay
of trace amounts of uranium found in the earth's crust throughout
the world. It is an unstable gas that quickly breaks down
and dissipates in the air.
Radon is measured
in units called picocuries per liter (pCi/L). A picocurie
is one trillionth (10 -12) of a curie, which is the amount
of radioactivity emitted by a gram of radium. The U.S. Environmental
Protection Agency (EPA) has established 4 pCi/L as the standard
for indoor air; 20 pCi/L represents the maximum amount of
exposure to radium that is now allowed by U.S. regulations.
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