Presentation on theme: "Radon I Rikhvanov Leonid P., professor, DSc in Geology and Mineralogy Nadeina Luiza V., associate professor, PhD in Philology TOMSK -2015."— Presentation transcript:
Radon I Rikhvanov Leonid P., professor, DSc in Geology and Mineralogy Nadeina Luiza V., associate professor, PhD in Philology TOMSK -2015
Radon is a class a known human carcinogen Alpha particles from radon decay products can damage lung tissue Lung cancer is the main health effect
HISTORY An “unknown” lung disease in miners in the 1400s Identified in 1879 in autopsies of European miners as lung cancer (Limphosarcoma). Excess lung cancer deaths observed in uranium miners in US, France, Czechoslovakia, Canada. Excess lung cancer deaths in other underground miners in Sweden, Britain, France, Australia, China and US
Mechanism of Lung Cancer Induction Radon and RDPs breathed in. Radon exhaled. RDPs remain stuck to lung issue. Po-218 and Po-214 emit alpha particles. Alpha particles strike lung cells causing physical and chemical damage to DNA.
Physical and chemical damage to DNA from radiation Physical damage occurs when DNA stuck directly. Chemical attack can occur from ions and free radicals created when radiation impacts fluid surrounding DNA
Scientific basis for radon risk estimates Studies on miners. Committee on the biological effects of ionizing radiation. Studies on residential occupants. Laboratory animal studies.
EPA Risk Assessment Radon-related lung cancer risk: - life time risk at 4 pCi/L Action Level: 1:100 for smokers 1:1000 for non-smokers - Central risk estimate: 14000 lung cancer deaths/year uncertainty range: 7000 to 30000 deaths/year
IDNS state policy recommends that people not have long-term exposures above 4.0 pCi/L
It is in the interest of people to establish a comprehensive program for determining the extent to which radon and radon progeny are present in dwellings and in other buildings at levels that pose a potential risk to the occupants and foe determining measures that can be take to reduce and prevent such a risk.
Working level month The actual potential for contracting lung cancer increases with the dose received and the duration of expose to a given dose. A time and a dose measure is used to quantify lung cancer potential. This is the Working Level Month (WLM). Equivalent to 170 hours of exposure at I Working Level (WL).
Conclusions: Estimates for U.S. -15000 lung cancer deaths/year 10000 in smokers 5000 in never smokers Uncertainty Range = 6000-36000/yr Liner dose-response Little credible evidence for a threshold effect Increased risk for nonsmokers confirmed Higher risk associated with exposure received at low rates