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Radon 101 Menasha Health Department Environmental Health
Vocabulary Uranium: A radioactive element generally found in the environment. As uranium decays, it releases radiation and forms other elements (like radium and radon) until it becomes a stable element (lead). Radon: A naturally occurring radioactive gas found in soils, rock and water throughout the United States. Radon causes lung cancer and is a threat to health because it tends to collect in homes, sometimes to very high concentrations. As a result, radon is the largest source of exposure to naturally occurring radiation
Vocabulary Radioactive decay: The process in which an unstable nucleus emits radiation and changes to a more stable isotope or element. A number of different particles can be emitted by decay. The most typical are alpha or beta particles, often accompanied by gamma radiation.
Radon Radon comes from Uranium in the ground via a series of radioactive decays You can’t see, smell or taste it It is found all over the US It can get into any type of building The only way to know if a building has radon is to test for it
Half Life Half-life: The amount of time it takes for half of the radioactive atoms in a sample to decay into a more stable form. Half Life of Radon is 3. 8 days
PARENTS AND PROGENY OF RADON-222 IN THE GROUND Po-218 Rn-222 Ra-226 IN THE AIR alpha 3. 8 d Pb-214 3 min alpha 27 min 1600 y beta Bi-214 Th 20 min beta U-238 Pb-210 alpha Po-214 0. 0002 s 4. 5 E 9 y 21 y
How does radon get into buildings? Construction joints Cracks or gaps in floors and walls Gaps around service pipes and through water supply lines Drain tiles and sump pump crocks
Sandy Soil Strong Radon Sources Clay ALL HOMES HAVING CONTACT WITH GROUND SHOULD BE TESTED, WHETHER CHANCE ELEVATED IS 1% OR >20% ALL HOMES SHOULD BE TESTED
RADIUM OFTEN TENDS TO CONCENTRATE IN SOIL B HORIZON BACKFILL IS SOIL E & B; TOPSOIL O AND A ARE USED ELSEWHERE Geologic Soil and Bedrock PLEISTOCENE
ESTIMATED PERCENTAGES OF HOMES WITH RADON > 4 p. Ci/L, MAIN FLOOR YEAR AVERAGE BY ZIP CODES; 87, 000 MEASUREMENTS Menasha % > 4 p. Ci/L 0 – 1% 1 – 10% 10 – 20% > 20% < 4 MSMTS.
Different Types of Radiation and their impact on the body Alpha radiation Impacts tissue surface Beta Radiation Enters tissue but does not pass through Gamma Radiation Travels through tissue all the way through the body
Health Risks of Radon Deposits of radioactive decay in lungs Increases chance of lung cancer 20+ years later Radon exposure is the second leading cause of lung cancer in nonsmokers
Radon Testing Short Term Testing 48 hours Minimum Activated Charcoal Place in the most occupied room in the lowest level of the house 20” above the floor
Radon Follow-Up Testing Alpha Track Detector 90 to 365 Days Will average level throughout the seasons
Radon Levels US EPA Radon action level: 4 p. Ci/L
RADON CONTROL FOR EXISTING HOUSES: SUB-SLAB DEPRESSURIZATION FAN SEAL CRACKS AND OPENINGS TO SOIL DEPRESSURIZED ZONE
WHEN BASEMENT AIR PRESSURE (d. P) GOES DOWN, RADON ENTRY INCREASES. THE DAY BEFORE STACK FAN FIRST TURNED ON, INSTALLERS VENTILATED BASEMENT.
SUB-SLAB DEPRESSURIZATION FAN ON AND OFF; TWO WINDOWS OPENED 3”, CLOSED Feb 24 - March 2 RADON, p. Ci/L TURN FAN OFF BEDROOM TURN FAN ON CLOSE OPEN TIME, HOURS
POPULATION-AVERAGED PUBLIC EXPOSURES TO IONIZING RADIATION (PIE: DOSE, = CANCER RISK EQUIVALENT RADON 54% IS DUE TO AVERAGE INDOOR RADON: 1. 3 p. Ci. L
Conclusion Radon can be dangerous Testing is the only way to know if radon is present If radon levels are high, mitigation will effectively reduce radon to levels <4 p. C/L Questions – Contact the Menasha Health Department (920) 967 -3520 tdrew@ci. menasha. wi. us