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Education and Culture Lifelong Learning
Programme ERASMUS
Assist.Prof.Dr. Lucija Hanic
LECTURE 4 Protection of human dwellings against
radon www.fg.uni-mb.si/lucija/presentations/2008s
akarya-lecture4.ppt
14 18 April 2008
Home institution University of Maribor Faculty of
Civil Engineering Slovenia
Host institution Sakarya University Technical
Education Faculty Turkey
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Radon and radiation
Click for Periodic table
Radon is an inert gas, which means that it is
chemically unreactive and at atmospheric
conditions it is in gaseous form. It is found in
form of three isotopes that are all unstable.
Half-life is a time period in which half of
initial number of radioactive nuclei dacays.
Unstable nuclei decay spontaneously into lighter
nuclei by emitting particles or energy. The
result of this proces is radiation most well
known are a, ß and ?.
Sheet of paper
Since radiation is a natural phenomena our body
receives an annual dose of irradiation from
natural sources which is amounts to 2.4 mSv.
Aluminium plate
Lead block
Radiation dose measured in Sieverts (Sv) is
estemated on the basis of the damage caused on
the tissue by a certain type of radiation.
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Table 1. Annual doses from different irradiation
sources.
Figure 4. Natural sources of radiation and their
contribution to annual dose.
Irradiation caused by radon and its decay
products is one of the important reasons for lung
cancer.
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Radon sources in dwellings
1. Cracks in solid floors 2. Construction joints
3. Cracks in walls 4. Gaps in suspended floors
5. Gaps around service pipes 6. Cavities inside
walls 7. The water supply
Table 2. Concentration of 226Ra in some materials
used in construction industry.
Indoor concentration
1 Bq 1 decay per second 1 Ci 3.71010 Bq
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Methods for radon reduction
New buildings 1. Careful selection of materials
2. Risk assasment evaluation of soil 3.
Adequate building design
Old buildings 1. Determination of radon
concentration (short-term, long-term) 2. Source
determination (soil, building materials,
water) 3. Instalation of adeqate radon mitigation
system
Water Activated carbon filters Aeration Point
of entry or Point of use
Soil Sealing cracks Soil depressurization House
pressurization Natural ventilation Heat recovery
ventilation
Material Reducing air pressure in cavity walls
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Further reading
Field R.W., radon occurrence and health risk,
College of Public Health, Iowa,
http//www.cheec.uiowa.edu/misc/radon_occ.pdf,
lt09.04.2008gt. Nazaroff WW, Nero AV (eds) Radon
and Its Decay Products in Indoor Air. New York,
John Wiley Sons, 1988. Field RW, Steck DJ,
Smith BJ, Brus CP, Fisher EL, Neuberger JS, Platz
CE, Robinson RA, Woolson RF, Lynch CF
Residential Radon Gas Exposure and Lung Cancer
The Iowa Radon Lung Cancer Study, American
Journal of Epidemiology 151(11)1091-102, 2000.
A citizans guide to radon. U.S. Environmental
Protection Agency, http//www.epa.gov/radon/pubs/c
itguide.html, lt09.04.2008gt.
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