Radon control

The types of mechanical barriers that have been tried or suggested for radon control lit into one... 

The first problems on the list are not specific to radon control but are encountered on nearly every construction job. In spite of quality control and communication problems and the understandable wariness builders show when asked to build something in a different way, the residential construction industry has responded to new techniques, materials, and public demands. The average house being built today is very different from a home built 20 years ago. If a product or a method can be demonstrated to reliably keep radon out without presenting significant problems with cost, scheduling, or installation, many builders would learn to use it. The major difficulty faced by mechanical barrier approaches is the thoroughness that seems to be required to ensure that no radon problem will occur. 

It is recommended, for potential radon control, to seal open blocks at the time of construction. Block tops have been successfully sealed using... 

Bocanegra, R. and P.K. Hopke, The Feasibility of Using Activated Charcoal for Indoor Radon Control, this volume (1987). 

Jebackumar, R., Feasibility of Radon Control from High Volume Flows and Indoor Air, Master of Science Thesis, Nuclear Engineering Program, University of Illinois at Urbana-Champaign, (1985). 

Activated carbon alpha activity, 282 conditions for optimal performance, 568 contaminants adsorbed, 568 feasibility for indoor radon control, 560-568... 

The EPA issued Model Standards and Techniques for the Control of Radon in New Residential Buildings in 1994. The publication was intended to serve as a model for jurisdictions developing building codes or standards apphcable to their radon control requirements, primarily for one- and two-family homes and other residential buildings of three stories or less. There is no requirement in the Act that new homes meet any specific radon level or that private home owners must test their homes. Consistent with its limited authority under the Act, the EPA was careful to point out in several sections that the Model Standards were not intended to supersede radon resistant... 

Radon—Requires the USEPA to withdraw its proposed radon standard and to set a new standard in 4 years, after NAS conducts a risk assessment and a study of risk-reduction benefits associated with various mitigation measures. Authorizes cost/benefit analysis for radon, taking into account the costs and benefits of indoor air radon control measures. States or water systems obtaiiving USEPA approval of a multimedia radon program in accordance with USEPA guidelines would only have to comply with a weaker "alternative maximum contaminant level" for radon that would be based on the contribution of outdoor radon to indoor air. 

Inhalation dose of radon gas depended on the time of exposure, at 30 days of exposure to 456Bq/m of indoor radon, dedication of cancer tissue on the rabbit s lung don t appeared, as shown in Fig.3. Number zero in Fig.l represents the lung tissue (slide) for the Rabbits was not exposed to radon (control), and number one is for the rabbits that exposed to radon concentration (543 26.87B/m ) within 30 days. While a time of exposure increased to 60 days for the same dose and concentration make an increase of deformation of the exposure tissue without any indication of cancer, as shown in Fig.4, number 2. 

New explosives controls - Do they affect you (The Control of Explosives Regulations 1991) What your doctor needs to know Radon m the workplace... 

Deals with issues that affect the quality of our air and protection from exposure to harmful radiation. OAR de >el-ops national programs, technical policies, and regulations for controlling air pollution and radiation exposure. Areas of concern to OAR include indoor and outdoor air quality, stationaiy and mobile sources of air pollution, radon, acid rain, stratospheric ozone depletion, radiation protection, and pollution prevention. 

American Academy of Environmental Medicine (AAEM), 277 American Association for Aerosol Research (AAAR), 267 American Association of Pharmaceutical Scientists (AAPS), 267 American Association of Poison Control Centers (AAPCC), 277 American Association of Radon Scientists and Technologists (AARST), 267... 

Radon is a noble gas and is therefore not readily ionized or chemically reactive. Its properties in terrestrial material will be controlled by its solubility in melt and fluid as well as its diffusion coefficients. Compared with the lighter noble gases, Rn diffuses more slowly and has a lower solubility in water. It will also more readily adsorb onto surface that the lighter rare gases. It can, however be lost by degassing in magmatic systems (Condomines et al. 2003). More information about the behavior of Rn can be found in Ivanovich and Harmon (1992). 

Like most other indoor air contaminants, radon can be controlled by keeping it out of the house, or reducing the concentration by mixing it with fresh air after it has already entered. The following approaches have been tried or suggested9 ... 

It should be pointed out that attempts to control radon by making a gastight barrier around the foundation have not been completely effective. It is likely that they have done some good, but many... 

The application of dampproofing and waterproofing materials on the exterior, interior, or both sides of the foundation that can serve as a radon-resistant barrier is recommended to help control radon entry. It must be understood that a coating applied to a foundation intended to resist the flow of radon into the building is in addition to the normal waterproofing/dampproofing requirements. 

In theory, the application of radon barriers should be adequate to avoid elevated radon levels in houses. In practice, however, a backup radon mitigation system has been found essential for maintaining indoor radon concentrations below 4 pCi/L in most homes studied. In the recent radon-resistant residential construction projects conducted by U.S. EPA and/or private builders, several of the homes designed to be radon resistant have contained radon concentrations above 4 pCi/L. In each of those houses, a backup system consisting of an active (fan-assisted), or passive (wind-and-stack-effect-assisted), SSD system was installed at the time of construction. When mechanical barriers failed to adequately control radon, the soil depressurization methods were made operational. 

Membranes of plastics and rubbers that are used to control liquid water penetration and water vapor diffusion are effective in controlling air movement as well. If they can be adequately sealed at the joints and penetrations and installed intact, then they could also provide a mechanical barrier to radon entry. 

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