BecTec uses LS (Liquid Scintillation) Radon Detectors for short-term measurement. These LS detectors are made are approved by AARST-NRPP and meet the EPA Indoor Radon and Radon Decay
Radon ( Rn) is a radioactive, colorless, odorless, tasteless noble gas, occurring naturally as a decay product of radium.
Radon has been considered the second leading cause of lung cancer and leading environmental cause of cancer mortality by the United States Environmental Protection Agency. Others have reached similar conclusions for the United Kingdom, France and Canada. Radon exposure in homes and offices may arise from certain subsurface rock formations, and also from certain building materials (e.g., some granites). The greatest risk of radon exposure arises in buildings that are airtight, insufficiently ventilated, and have foundation leaks that allow air from the soil into basements and dwelling rooms.
Radon BC Map of Potential Radon Exposures CLICK LINK
The Minister recommends that:
• Remedial measures should be undertaken in a dwelling whenever the average annual radon concentration exceeds 200 Bq/m³ in the normal occupancy area.
• The higher the radon concentration, the sooner remedial measures should be undertaken.
• When remedial action is taken, the radon level should be reduced to a value as low as practicable.
• The construction of new dwellings should employ techniques that will minimize radon entry and will facilitate post-construction radon removal, should this subsequently prove necessary.
The aim is to remediate and reduce the radon concentration to less than 200 Bq/m³ (5 pCi/L). If the radon concentration is found to be greater than 600 Bq/m³ (pCi/L), the remedial actions are recommended to be completed in less than a year; between 200 Bq/m³ and 600 Bq/m³, the remedial actions should be completed in less than two years.
Since radon is a colorless, odorless gas the only way to know how much is present in the air or water is to perform tests. In BC radon test kits are available to the public at retail stores and Health Agencies, for home use. However, short-term testing is available through licensed professionals, who are often home inspectors. Efforts to reduce indoor radon levels are called radon mitigation. In Canada and the US Health Canada the EPA-Environmental Protection Agency recommends all houses be tested for radon.
Accumulation in buildings
High concentrations of radon in homes were discovered by chance in 1985. Typical domestic exposures are of approximately 100 Bq/m3 (2.7 pCi/L) indoors. Some level of radon will be found in all buildings. Radon mostly enters a building directly from the soil through the lowest level in the building that is in contact with the ground. High levels of radon in the water supply can also increase indoor radon air levels. Typical entry points of radon into buildings are cracks in solid foundations, construction joints, cracks in walls, gaps in suspended floors, gaps around service pipes, cavities inside walls, and the water supply. Radon concentrations in the same location may differ by a factor of two over a period of 1 hour. Also, the concentration in one room of a building may be significantly different from the concentration in an adjoining room.
The distribution of radon concentrations will generally change from room to room, and the readings are averaged according to regulatory protocols. Indoor radon concentration is usually assumed to follow a lognormal distribution on a given territory. Thus, the geometric mean is generally used for estimating the "average" radon concentration in an area.
The mean concentration ranges from less than 10 Bq/m3 to over 100 Bq/m3 in some European countries. Typical geometric standard deviations found in studies range between 2 and 3, meaning (given the 68–95–99.7 rule) that the radon concentration is expected to be more than a hundred times the mean concentration for 2 to 3% of the cases.
Health Risk - Domestic-level exposure
Radon exposure has been linked to lung cancer in numerous case-control studies performed in the United States, Europe and China. There are approximately 21,000 deaths per year in the US due to radon-induced lung cancers. One of the most comprehensive radon studies performed in the United States by Dr. R. William Field and colleagues found a 50% increased lung cancer risk even at the protracted exposures at the EPA's action level of 4 pCi/L. North American and European Pooled analyses further support these findings.
Radon (222Rn), decays to 210Pb and other radioisotopes. The levels of 210Pb can be measured. The rate of deposition of this radioisotope is weather-dependent. Radon concentrations found in natural environments are much too low to be detected by chemical means. A 1000 Bq/m3 (relatively high) concentration corresponds to 0.17 picogram per cubic meter.
Radon concentration in the atmosphere is usually measured in.
(Bq/m3) - becquerel per cubic meter -SI derived unit
(pCi/L) - picocuries per liter (US common unit of measurement)
1 pCi/L=37 Bq/m3
222Rn, has a half-life of 3.8 days and is the most stable isotope, .
210Pb is formed from the decay of 222Rn. It has a short half-life of 55 seconds.
Typical Average Domestic Exposures:
- 48 Bq/m3 indoors, though this varies widely,
- 15 Bq/m3 outdoors
Radon is produced by the radioactive decay of radium-226, which is found in uranium ores, phosphate rock, shales, igneous and metamorphic rocks such as granite, gneiss, and schist, and to a lesser degree, in common rocks such as limestone. Every square mile of surface soil, to a depth of 6 inches (2.6 km2 to a depth of 15 cm), contains approximately 1 gram of radium, which releases radon in small amounts to the atmosphere.
Radon concentration varies widely from place to place. In the open air, it ranges from 1 to 100 Bq/m3, even less (0.1 Bq/m3) above the ocean. In caves or aerated mines, or ill-aerated houses, its concentration climbs to 20–2,000 Bq/m3.
Radon mostly appears with the decay chain of the radium and uranium series (222Rn), and marginally with the thorium series (220Rn). The element emanates naturally from the ground, and some building materials, all over the world, wherever traces of uranium or thorium can be found, and particularly in regions with soils containing granite or shale, which have a higher concentration of uranium. Not all granitic regions are prone to high emissions of radon. Being a rare gas, it usually migrates freely through faults and fragmented soils, and may accumulate in caves or water. Owing to its very short half-life (four days for 222Rn), radon concentration decreases very quickly when the distance from the production area increases. Radon concentration varies greatly with season and atmospheric conditions. For instance, it has been shown to accumulate in the air if there is a meteorological inversion and little wind.
Indoor Radon and Radon Decay - Product Measurement Device Protocols
U.S. Environmental Protection Agency - EPA Link
Office of Air and Radiation (6604J)
July 1992 (revised)
PRODUCT MEASUREMENTS IN HOMES - PROTOCOLS FOR RADON AND RADON DECAY
Office of Air and Radiation (6609J)
EPA 402-R-93-003, June 1993
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