Radon buildings

Care must be taken in handling radon, as with other radioactive materials. The main hazard is from inhalation of the element and its solid daughters which are collected on dust in the air. Good ventilation should be provided where radium, thorium, or actinium is stored to prevent build-up of the element. Radon build-up is a health consideration in uranium mines. Recently radon build-up in homes has been a concern. Many deaths from lung cancer are caused by radon exposure. In the U.S. it is recommended that remedial action be taken if the air in homes exceeds 4 pCi/1. 

The Clinton experience can be contrasted with radon observations in Boyertown, Pennsylvania, where buildings with radon concentrations over 500 times the U.S. EPA action level were found adjacent to buildings below the action level.48 Therefore, the presence of elevated-radon buildings in a neighborhood is at best only an indication that the probability of having a radon problem has increased. 

Mueller Associates, Inc., Syscon Corporation, and Brookhaven National Laboratory, Handbook of Radon in Buildings, Hemisphere Publishing Corporation, New York, 1988, p. 95. 

Radon from the soil can enter buildings through cracks in the foundation when the pressure inside is lower than in the soil. The rate of infiltration depends on the soil type, the building structure, and the pressure differential between the soil and the building,... 

Radiation other titan radon Estimated 360 eaneers per year. Mostly from building materials. Medieal exposure and natural baekground levels not ineluded. 

As the science of indoor air quality has matured, indoor air professionals have realized that many indoor air contaminants and the associated health effects are linked to specific types of buildings and their characteristics. For example, radon is primarily an indoor air concern in homes because of the ease with which it can be transported inside residential construction from the soil beneath. On the other hand. Sick Building Syndrome (SBS) primarily afflicts office building occupants who experience acute health and comfort effects that appear to be linked to time spent in a specific building. 

Radon (Rn) is a naturally occurring radioactive gas. Radon enters buildings from underlying soil and rocks as soil gas is drawn into buildings. 

The primary source of radon in most buildings is the surrounding soil and rock, well water, earth-based building materials. 

The radioactive gas radon seeps out of the ground a product of radio. tiv< processes deep in the Earth. There is now some concern that its. iimnlation in buildings and its nuclear decay products can lead to dangerou, . h Vs I-, ot... 

Radon Entry into Buildings A house will contain radon if the following four conditions exist ... 

A driving force exists to move the radon to the building. 

The most common way radon enters a building is when lower indoor air pressure draws air from the soil, bedrock, or drainage system into the house. If there is radon in the soil gas, it will also be drawn in. Just as gravity will make water flow from a high elevation to a lower elevation, pressure differences will make radon-laden air move from an area of higher pressure to an area of lower pressure. For a variety of reasons, most buildings tend to maintain an indoor air pressure lower than outdoor air pressure. If cracks and holes in the foundation are open to the soil, radon will be drawn indoors. Radon movement by pressure differences is called pressure-driven transport. 

Radon can also enter buildings when there are no pressure differences. Place a drop of food coloring in a glass of water eventually, the coloring will spread out (diffuse) and color the water— even without stirring. Radon will do the same thing—spread from an area of higher concentration to an area of lower concentration until the concentrations are equal. Radon movement in this way is called diffusion-driven transport. 

Radon can also emanate from the building materials themselves. The extent of the use of radium-contaminated building materials is unknown but is generally believed to be small. 

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