Research Poster 36 x 48 - A

1
13 Radon A Deadly Carcinogen in the Geologic
Environment
Joni Osborn, Western Oregon University Faculty
Advisor Steve Taylor, PhD
Health Connection
Geologic Process/Phenomena
Abstract
Introduction
The radioactivity decay of Uranium produces the
radioactive decay of radium which radon gas is
the result. Radon gas (222Rn) is one of three
radon isotopes 219Rn, 220Rn, and 222Rn. Uranium
is found in granite, uranium-enriched, and
phosphatic rocks, uraniferous metamorphic rock.
Granites in southwestern England, the Czech
Republic, and Germany have high radon levels. The
United States has a variety of land formations
that produce high levels of radon. Some of these
are uraniferous metamorphic rocks in the Rocky
and Appalachian Mountains and the Sierra Nevada.
Marine black shales from Ohio to Colorado
contain high amounts of radon (Appleton, 2005).
Figure 2.
Radon is a radioactive, naturally occurring
noble gas. A noble gas is odorless, colorless,
tasteless and has relatively low chemical
reactivity. Radon is the product of the decay of
radium. Radium is the product of the radioactive
decay of uranium (Appleton, 2007). Radon gas is
found throughout the United States and the world.
Radon gas disperses in the open air but
accumulates in enclosed areas. It is in these
enclosed areas where increased levels of radon
become a health hazard. There are ways to
mitigate radon gas in homes and buildings.
Extensive amount of epidemiological data has
accumulated over several decades relating to
studies of the incidence of lung cancer in
miners. These studies consistently demonstrated
an increase in lung cancer incidence with
exposure to radon decay products
(Appleton2005).
Radon A Deadly Carcinogen in the Geologic
Environment   Radon is a naturally occurring
noble gas that results from radioactive decay in
uranium-bearing bedrock and regolith. Radon
occurs in a variety of geologic settings around
the world, including the United States. Bedrock
sources most associated with radon include
metamorphic rocks and granites, black shales,
feldspathic glacial deposits, and uranium ores.
Health hazards associated with this gas include
lung and stomach cancers, caused primarily by
inhalation or ingestion. Radon exposure
increases chances of lung cancer deaths in
smokers and miners who work in underground
enclosures. Radon hazard mapping helps locate
risk areas and guides public health protection.
Global hot spots for radon exposure include the
Sierra Nevada-Rocky-Appalachian mountain regions
of the U.S. , glacial terrains of the upper
Midwest, Great Britain, Norway, and the Czech
Republic. This paper provides an overview of the
geochemistry behind radon occurrence and presents
examples of mitigation projects from around the
world.
Radon is the number one cause of lung cancer
among non-smokers, according to EPA estimates.
Radon is responsible for about 21,000 lung cancer
deaths every year (EPA 2010). Figure 4. Radon
causes 11 of lung cancer deaths among smokers
(most of whom die of smoking) but 23 of
never-smokers (Appleton, 2005). The U.S. EPA
estimates that radon in drinking water causes
about 168 cancer deaths per year, 89 from lung
cancer caused by breathing radon released from
water, and 11 from stomach cancer caused by
drinking radon-containing water (Appleton,
2005).
Radon enters buildings and homes by 3 pathways.
Figure 3. Radon gas migrates up from the ground
underneath the basements of foundations following
minute pathways. Cracks in the foundations,
floors, walls and areas below grade, gaps around
service pipes entering the house, are all
potential entrances for radon gas. Houses in the
United States with basements have a greater
incident of higher radon levels (Appleton 2005).
Household water sources that come from enclosed
groundwater have the potential of having higher
levels of radon because there is not a way to
allow the degassing of the water. Aeration of
radon laden water while running the shower or
faucets allows the radon gas to enter the air in
the building. Building products that have been
made with radioactive shale add to high radon
concentrations.
Figure 4. A cancerous lung
Summary
Radon mapping helps to determine if radon
protective measures may be needed in new
buildings, cost-effectiveness of radon monitoring
of existing buildings, and to provide a radon
assessment for home buyers and sellers (Appleton,
2007). Since radon can seep into homes through
cracks in the foundations, service pipe
entrances, or any opening no matter what size,
eliminating the radon is essential. This means
keeping the radon out, remove what is inside or
dilute it with fresh air. To keep radon out seal
all openings and cracks. Use a low ventilation
fan that pumps air from the basement to above the
roof line. Diluting the radon gas with fresh air
is best for unused basements because it is not
economical because of increased heating or
cooling costs (The Natural Handyman, 2009)
Figure 1. Orange counties moderate potential,
Yellow counties low potential of radon
Case Examples
According to the Environmental Protection Agency
(EPA), twenty-three out of thirty-six Oregon
counties have the potential for moderate levels
of radon with the other sixteen counties have
the potential of low levels of radon (EPA 2010).
Polk County falls into the potential of low
level. Figure 1. According to Appleton (2005)
Studies of thousands of miners, some with
follow-up periods more than thirty years, have
been conducted in uranium, iron, tin, and
fluorspar mines in Australia, Canada, China,
Europe and the United States. The results
consistently demonstrated an increase in lung
cancer incidence with exposure to radon decay
products. The miner studies prove low exposures
over longer periods produced greater lung cancer
risk than high exposures over short periods
(Appleton, 2005).
Figure 3. Keller, 2011 Environmental Geology
Prentice Hall 511
References
Contact
Appleton, J. D., 2007, Radon Sources, Health
Risks, and Hazard Mapping Royal Swedish Academy
of Sciences, 85-88. Appleton, J. Donald, 2005,
Essentials of Medical Geology British Geological
Survey, 227-262 Environmental Protection Agency,
EPA Map of Radon Zones, URLhttp//www.epa.gov/rad
on/zonemap.html The Natural Handyman, 2009, Radon
in the Home...How Dangerous is it...Really?
Internet Web Resource, URL http//www.naturalhand
yman.com/iip/infsisters/infradon/infradon.html
Name Joni Osborn Organization Western
Oregon University Dept. of Earth and Physical
Sciences Email jeggleston09_at_wou.edu
Figure 2. Potential Radon map