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High radon levels in a Minnesota (USA) basement with a passive under slab vent pipe system can be seen in the left half of the graph. After installation of a radon fan (ASD), a permanent reduction in radon levels to approximately 0.6 pCi/L can be seen in the right half of the graph. The most common approach is active soil depressurization (ASD).
In a working mine, the radon level can be controlled by ventilation, sealing off old workings and controlling the water in the mine. The level in a mine can go up when a mine is abandoned; it can reach a level which can cause the skin to become red (a mild radiation burn). The radon levels in some of the mines can reach 400 to 700 kBq m −3. [17]
Very high radon concentrations (>1000 Bq/m 3) have been found in houses built on soils with a high uranium content and/or high permeability of the ground. If levels are 20 picocuries radon per liter of air (800 Bq/m 3 ) or higher, the home owner should consider some type of procedure to decrease indoor radon levels.
Radon is measured in picocuries per liter of air (pCi/L) or becquerel per cubic meter (Bq m-3). Both are measurements of radioactivity. The World Health Organization (WHO) sets the ideal indoor radon levels at 100 Bq/m-3. [97] In the United States, it is recommend to fix homes with radon levels at or above 4 pCi/L.
Under this modeling, the best policy is obviously to reduce the radon levels of all homes where the radon level is above average, because this leads to a significant decrease of radon exposure on a significant fraction of the population; but this effect is predicted in the 0–200 Bq/m 3 range, where the linear model has its maximum uncertainty ...
A slab-on-grade or basement floor should be poured over a cross-laminated polyethylene vapor barrier over 4 inches (10 cm) of granular fill to prevent wicking of moisture from the ground and radon gas incursion. Inside a steel building, water vapor will condense whenever it comes into contact with a surface that is below the dew point temperature.
A real-valued Radon measure is defined to be any continuous linear form on K (X); they are precisely the differences of two Radon measures. This gives an identification of real-valued Radon measures with the dual space of the locally convex space K (X). These real-valued Radon measures need not be signed measures.
To achieve these aims, WHO has formed a network of key partner agencies from some 40 Member States. This network is the basis for the WHO International Radon Project which was launched in 2005. Working groups will collect and analyse information on radon risk, radon policies, radon mitigation and prevention as well as risk communication. The ...