450 likes | 567 Views
Radon… Why Should I Care?. Brandy Toft Air Quality Specialist Leech Lake Band of Ojibwe ITEP IAQ Course March 2013. What Is Radon?. Radon: odorless , colorless, toxic gas derived from decay of uranium in soil Form of radiation that attacks lung tissue
E N D
Radon… Why Should I Care? Brandy Toft Air Quality Specialist Leech Lake Band of Ojibwe ITEP IAQ Course March 2013
What Is Radon? • Radon: odorless, colorless, toxic gas derived from decay of uranium in soil • Form of radiation that attacks lung tissue • #1 cause of lung cancer among non-smokers • Estimated 21,000 deaths year, rising • Smoking increases your risk 4 times! • Elevated indoor levels found in every state
Where Does Radon Come From? • Caused by breakdown of Uranium in earth’s crust. Present in almost all rock, soil, and water • Amount of radon in soil depends on soil chemistry, which varies greatly from one house to next • Moves up through ground into atmosphere, where it can potentially enter your home through cracks/holes in foundation
4 day Radon-222 a,g 3 min Polonium-218 a,g 27 min Lead-214 b,g 20 min Bismuth-214 b,g 0.2 ms Polonium-214 a,g Lead-210 22 yrs b,g Bismuth-210 5 day b,g Polonium-210 138 day a,g Lead-206 Stable Radon Decay Products Po-218 and Po-214 Deliver majority of radiation dose to lungs
Could My Home Have Radon? • 1 in 15 homes in US are above 4 piC/L. ALL HOMES SHOULD BE TESTED FOR RADON! Regardless of location, zone, home design or if your neighbor tested. • Are YOU at risk for lung cancer due to high radon levels? TEST YOUR HOME!
Houses Suck…. Radon
Examples of Entry Points • Cracks in concrete slabs • Spaces behind brick veneer walls that rest on uncapped hollow block foundations • Pores and cracks in concrete blocks • Floor-wall joints (cold joints) • Exposed soil (eg., sump or crawl space)
Examples of Entry Points (cont.) • Weeping (drain) tile, if drained to an open sump • Mortar joints • Loose fitting pipe penetrations • Open tops of block walls • Building materials, such as brick, concrete, rock • Well water
Radon: Lung Cancer Causing Gas • Radon decays into radioactive alpha particles; articles are inhaled, deposited in lungs • Causes physical damage to DNA, increasing potential for cancer
What Level of Rn is Considered Safe? • No known safe level of radon • 9 to 12% of lung cancers are radon induced • EPA recommends homes with radon levels over 4 pCi/L be mitigated • Not a health-based standard • Based on mitigation technology • WHO health based action level 2.7 pCi/L
Health Effects Radiation is a carcinogen(cancer-causing agent) Most cancers do not appear until many years after radiation dose (~10-40 years) • Radiation may also cause other health effects • links to leukemia, stomach & liver cancer • exposure during pregnancy potential links • Genetic defects in children • Developmental disabilities
Health Effects (cont.) • 2ndleading cause of lung cancer in US • Estimated to cause 21,000 deaths annually* • Second only to smoking • Leading cause of lung cancer for non-smokers • 2,900 deaths annually * EPA Assessment of Risks from Radon in Homes (June 2003, EPA -402-R-03 -0003)
More to come…. Adverse health effects of radon will increase as more people Are exposed in tighter homes Population ages Medical-related radiation exposure increases Prevention and mitigation methods reduce risk
Comparing Radon Related Cancer to Other Cancer Types “Stigma” of lung cancer Lung Cancer (radon) 20000 Liver Cancer 18000 16000 Brain Cancer 14000 Stomach Cancer 12000 Annual U.S. Cancer Deaths 10000 Melanoma 8000 Oral Cancer 6000 4000 Gallbladder Cancer 2000 Bone Cancer 0 Source: Bill Field, 2005, UI
Chances Of Developing Cancer Due To Radon Depend On… • Levels of radon in home - Dose • Amount of time spent in home - Duration • Pre-Disposition • Smoker • Non-smoker • Previous Smoker • Genetics
Test, Fix, Save a Life • Everyhome should be tested • Testing is easy • No special skills required • Only takes a couple of minutes • It’s inexpensive – especially compared to medical treatment
TEST TEST TEST TEST TEST TEST.... Adverse health effects of radon will increase as more people are • Exposed in homes and work, • Our population ages, and • Increased medical-related radiation exposure
Radon on the Rez Located in medium to high zones of radon potential Started short term testing in 2005 Handed out over 700 tests 0.4 to 44 pCi/L Crawl spaces (cement and dirt) Basements Need to educate and test!
Short-Term Fixes…. Sealing cracks and other openings in foundation to limit radon flow into home House pressurization involves blowing air from upper floors or outside into lowest level of house (typically basement) to prevent radon from entering house
Short-Term Fixes…. (cont.) • Natural ventilationreduces radon levels by mixing radon with outside air • Typically a temporary measure due to increased heating/ cooling costs • Heat-recovery ventilator (HRV or air-to-air heat exchanger) can increase ventilation. • Increases heating/cooling costs, too, but not as much as natural ventilation
Long-Term Fixes For houses with basement or slab-on-grade • Subslab suction(or sub-slab depressurization) is most common method. • Pipes inserted through floor slab or below slab from outside house into crushed rock or soil underneath • Fan connected to pipes draws radon from below house, released into outdoor air • Drain tile suction • can be used in houses where perforated drain pipes installed to direct water from foundation, but only when tiles form complete loop around foundation
Long Term Fixes (cont.) • Sump hole suction can be used in houses with basements and sump pumps. • Sump can be capped, can continue to drain water and also serve as location for radon suction pipe • Block wall suction can be used to remove radon from hollow spaces in basement concrete block walls Forhouses with crawl spaces • Passive ventilation(without fan), or active(with fan) • Submembranedepressurization: covering earth floor with heavy plastic sheet, using vent pipe and fan to draw radon from under sheet
Don’t leave me hanging…. Test, test, test….what does it lead to? Tons of funds to identify problem… Where is money to fix problem? Many don’t have funds to fix themselves Have to be very creative to get mitigation $ How do we get it incorporated in with HUD? How do we get it incorporated into Housing?
Leech Lake Mitigations Three main types Sub floor subduction Sump pump Radon barrier Building capacity through training
2007 Radon Mitigation 24 to 2.5 PiC/L
Radon Resistant New Construction New homes can be built to be radon-resistant Minimize radon entry routes Allow for easier remediation of problems that may occur later Costs less if installed during construction (estimated $350 – $500 to cost of new home compared to $800 – $2,500 to retrofit existing home)
Radon-Resistant New Consruction Three categories • Sealing entry routes: basic element in radon mitigation • Similar to controlling moisture and for energy conservation. • Vapor barriers, caulks, foams can seal radon entry routes in foundation and floor areas. • Soil ventilation systems:soil depressurization or sub-slab depressurization systems. • Create suction on soil so radon is removed as soil gas before enteringhouse. • Some of these systems use fans (active systems) and some do not (passive systems)
RRNC (cont.) • Mechanical house ventilation systems • Designed to provide extra outside air dilution or to maintain higher pressure inside building relative to outside, preventing radon from entering
Basic elements of radon-resistant features • Gas Permeable Layer– Layer placed beneath slab or flooring system to allow soil gas to move freely underneath house. In many cases, material used is 4-inch layer of clean gravel • Plastic Sheeting - Placed on top of gas- permeable layer and under slab to help prevent soil gas from entering home. In crawlspaces, sheeting placed over crawlspace floor • Sealing and Caulking - All openings in concrete foundation floor sealed to reduce soil gas entry • Vent Pipe - 3- or 4-inch gas-tight or PVC pipe (commonly used for plumbing) runs from gas-permeable layer through house to roof to safely vent radon and other soil gases • Junction Box– Electrical junction box installed in case electric venting fan is needed later
Leech Lake Radon Mitigations • Radon Barrier Membrane • Sump Pump – drain tile • Sub floor subductions • active and passive systems • RRNC
A Lung Cancer Victim Speaks Dennie Edwards, Elyria, OH, www.cansar.org “In 2004, I had a very bad cold, so my doctor performed a chest x-ray to check for pneumonia. I've never smoked, so you can imagine how shocked I was that he found a 4.5 centimeter mass in my left lung. “Even though I've been a real estate agent for 31 years, I had never bothered to test my house for radon. I always informed my clients that radon testing prior to purchase was an option (to protect my liability), but truthfully, I really didn't care if they tested or not. “Now I had to wonder whether my lung cancer had been caused by radon exposure. While the doctor scheduled my surgery, I scheduled a radon test. The result was 10 pCi/l, (2 ½ times the EPA's Action Level). I had lived in the home for 12 years. Needless to say, I called a contractor to have a mitigation system installed. “Two days later I had surgery. I thought I was surely going to die. When I woke up choking with tubes in my throat, panic set in. They had removed my entire left lung. I'm getting better. I can walk up to a mile. But, I can no longer dance, lift things, or exert myself. “My clients now get a very personal testimonial about the importance of testing for radon."
Brandy Toft Air Quality Specialist Leech Lake Band of Ojibwe air@lldrm.org 218.335.7429