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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 Sidney,
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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