Radon: The Health Hazard with a Simple Solution Radon is a
cancer-causing natural radioactive gas that you can’t see, smell or
taste. Its presence in your home can pose a danger to your family's
health.
Radon is the leading cause of lung cancer among non-smokers.
Radon is the second leading cause of lung cancer in America and claims
about 20,000 lives annually.
Testing your home for radon can be easy and inexpensive, and if your levels are elevated, they can be lowered.
Radon
Radon is a chemical element that has the symbol Rn
and atomic number 86. Radon is a radioactive noble gas that is formed
by the decay of radium. It is one of the heaviest gases and is
considered to be a health hazard. The most stable isotope is 222Rn
which has a half-life of 3.8 days and is used in radiotherapy. Radon is
a significant contaminant that affects indoor air quality worldwide.
Radon gas from natural sources can accumulate in buildings and
reportedly causes 21,000 lung cancer deaths per year in the United
States alone.[1]
Notable characteristics
Essentially
chemically inert but radioactive, radon is the heaviest noble gas and
one of the heaviest gases at room temperature. At standard temperature
and pressure radon is a colorless gas, but when it is cooled below its
freezing point (202 K ; −71 °C ; −96 °F) it has a brilliant
phosphorescence which turns yellow as the temperature is lowered, and
becomes orange-red as the temperature is lowered further (below 93 K ;
−180 °C).
Natural radon concentrations in Earth's
atmosphere are so low that radon-rich water in contact with the
atmosphere will continually lose radon by volatilization. Hence, ground
water has a higher concentration of 222Rn than surface water, because
it is continuously produced by radioactive decay of 226Ra present in
rocks. Likewise, the saturated zone of a soil frequently has a higher
radon content than the unsaturated zone because of diffusional losses
to the atmosphere.
History
Radon
(named after radium) was discovered in 1900 by Friedrich Ernst Dorn,
who called it radium emanation. In 1908 William Ramsay and Robert
Whytlaw-Gray, named it niton (Latin nitens meaning "shining"; symbol Nt)
and isolated it, determined its density, and determined that it was the
heaviest known gas. It has been called "radon" since 1923.
The
first major studies of the health concern occurred in the context of
uranium mining, first in the Joachimsthal region of Bohemia and then in
the Southwestern United States during the early Cold War. Because radon
is a product of uranium, uranium mines have high concentrations of
radon and its highly radioactive daughter products. Many Native
Americans, Mormons, and other miners in the Four Corners region
contracted lung cancer and other pathologies as a result of high levels
of exposure to radon gas while mining uranium for the Atomic Energy
Commission in the mid-1950s. Safety standards instituted required
expensive ventilation and as such were not widely implemented or
policed.
The danger of radon exposure in dwellings
was discovered in 1984 with the case of Stanley Watras, an employee at
the Limerick nuclear power plant in Pennsylvania. Watras set off the
radiation alarms on his way into work for two weeks straight while
authorities searched for the source of the contamination. They were
shocked to find that the source was astonishingly high levels of radon,
around 100,000 Bq/m3 (2,700 pCi/L), in his house's basement and it was
not related to the nuclear plant. The risks associated with living in
his house were estimated to be equivalent to smoking 135 packs of
cigarettes every day. Following this event, which was highly
publicized, national radon safety standards were set, and radon
detection and ventilation became a standard homeowner concern.
Health Effects
Radon is the leading cause of lung cancer among non-smokers.