Air Quality Control 
Colorado's Top Installer of Radon Removal Systems

Call Toll-Free

1-800-NO-RADON

Free Estimates         Same-day Service         Guaranteed Results

Phone: (303) 466-2626 
Email: AQCA@Mail.com

Call Today for a Free Estimate to Fix Your Radon Problem:

(303) 466-2626    1-800-NO-RADON
http://www.mitigationsystem.com/coloradoradon.html  -   Call (303) 466-2626  -  Air Quality Control offers the following services: radon mitigation, testing, and remediation.  They specialize in radon gas abatement, measurement, reduction, and removal.  They are one of the Nation's largest radon companies and install high-quality, affordable radonmitigation systems.  To reduce your home's radon levels or for radon gas measurement options, contact Air Quality Control at 1-800-420-3881.  (Other [improper] search terms: raddon, raidon, raydon, radeon mitigator, midigation, radongas, radontesting mitigater, remitigation contractor, radon mediation, mitigaton company, abatment.) http://www.RadonDenverColorado.comAir Quality Control offers radon mitigation services throughout Colorado including the following cities: Denver, Littleton, Boulder, Broomfield, Aurora, Longmont, Fort Collins (Ft. Collins), Parker, Arvada, Englewood, Loveland, Castle Rock, Golden, Louisville, Westminster, Lafayette, Erie, Evergreen, Colorado Springs, Commerce City, Morrison, Elizabeth, Monument, Lyons, Windsor, Johnstown, Pine, Berthoud, Larkspur, Dillon, Dacono, Mead, Ward, and All of CO.  They install radon gas remediation systems in the following counties:  Jefferson, Arapahoe, Denver, Adams, Elbert, Douglas, Boulder, Gilpin, Clear Creek, Summit, Park County, Teller, Boulder, Grand, Eagle, Lincoln, El Paso, Crowley, Fremont, Chaffe, Lake, Pitkin, Jackson, Broomfield, Morgan, Washington, Weld, Larimer, Garfield, Routt, and all other Colorado Counties.  http://www.colorado-radon.com

Radon Mitigation

When a building (or house) is found to have an elevated level of radon gas (defined by the U.S. Environmental Protection Agency as a radon result of 4.0 pCi/l or higher,) methods of reducing the levels can be applied to cure the problem.  The most common method of Radon mitigation (also known as remediation or abatement) is Active Soil Depressurization (ASD.) This method utilizes PVC piping attached to an electric suction fan.  The piping typically begins below the lowest floor of the structure's foundation (penetrating the slab of the basement or the plastic membrane of the crawl space) and extends upward to an exit point above ground level.  The inline suction fan is mounted in an inconspicuous location on the exterior or within an attic above the home.  In cases where the radon fan is installed in the attic, the discharge pipe extends out through the roof so the gas can be released outdoors.

Active (fan assisted) radon mitigation systems can reduce the radon gas entry by as much as 99%.  A qualified radon contractor (also known as a radon mitigator or radon remediation specialist) can typically install a mitigation system in a home in less than a day.  After the system is installed, the radon levels begin to drop almost immediately.  Passive radon reduction techniques (such as sealing cracks or installing pipes without an inline fan) are rarely effective at reducing radon levels.  The reason that these "passive" techniques are ineffective is because radon gas is under pressure and must escape from the ground.  It is a very inert, un-reactive gas that can be drawn up through the pours of concrete, around drains, utility penetrations, or expansion joints.  Attempting to "seal out" radon is similar to trying to keep water out of a basement by painting the walls and floor with waterproofing paint.  It may work temporarily if the problem is minor, but it wouldn't keep standing water out.  The only way to fix a water problem is to redirect the water somewhere else before it enters the home.  The same principles apply to radon correction.  Sealing cracks and openings is part of the radon mitigation process; however this is to prevent the downward draw of conditioned air from the home and to improve the pressure field extension of the system below the slab.

What is Radon?

Radon is naturally occurring, odorless, and colorless gas produced by the breakdown of uranium in soil, rock, and water. Because radon is a gas, it can enter buildings through openings or cracks in the foundation. The radon gas itself decays into radioactive solids, called radon daughters. The radon daughters attach to dust particles in the air, and can be inhaled. The inhalation of radon daughters has been linked to lung cancer.

Radon has been identified as the second leading cause of lung cancer in the United States (second only to smoking.) The Environmental Protection Agency reports that radon causes between 15,000 and 22,000 lung cancer deaths every year in the United States.

Every home should be tested for radon regardless of where the home is located, the age of the home, foundation type, or whether or not the home is in an area where homes are “prone to having radon problems.” Homes with elevated radon levels have been found in practically every county in the United States.

The United States Environmental Protection Agency has established that if a home or building is found to have a radon level of 4 pCi/l or higher, action should be taken to reduce it. In most cases, radon levels can be reduced to 2 pCi/l or lower with the installation of an active (fan-assisted) venting system. As of September, 2009; The World Health Organization has established an action level of 2.7 pCi/l (100 Becquerel per cubic meter.) 

Radon’s primary hazard is caused from inhalation of the gas and its highly radioactive heavy metallic decay products (Polonium, Lead, and Bismuth) which tend to collect on dust in the air. The problem arises when these elements stick to the delicate cells lining the passageways leading into the lungs.

There is sufficient evidence for the carcinogenicity of radon and its isotopic forms, radon-222 and radon-220, in experimental animals. When administered by inhalation, preceded by a single exposure to cerium hydroxide dust, radon induced pulmonary adenomas, adenocarcinomas, invasive mixed adenosquamous carcinomas, and squamous cell carcinomas in male rats. Extrapulmonary metastases occurred in only one animal. Most or all of the tumors were believed to be bronchiolar or bronchio-alveolar in origin. Radon decay products in combination with uranium-ore dust induced a progression of activity from single basal cell hyperplasia in bronchioles to malignant tumors in male hamsters when exposed by inhalation. Lung tumors observed were adenomas, adenocarcinomas, and squamous cell carcinomas; bronchiolar and alveolar metaplasia, adenomatous lesions, fibrosis, and interstitial pneumonia were also observed. When administered by inhalation in combination with decay products, uranium-ore dust, and cigarette smoke, radon-induced nasal carcinomas, epidermoid carcinomas, bronchio-alveolar carcinomas, and fibrosarcoma were observed in dogs of both sexes. In general, a significant increase was observed in respiratory tract tumors in rats and dogs in comparison with unexposed animals. A dose- response relationship was noted in those experiments with rats in which radon was tested. In most instances, tumors at sites other than the lung were not reported, but in one study, mention was made of tumors of the upper lip and urinary tract in rats.

An IARC Working Group reported that there is sufficient evidence for the carcinogenicity of radon and its decay products in humans. Increased incidences of lung cancer have been reported from numerous epidemiologic studies of groups occupationally exposed to high doses of radon, especially underground hard rock miners. These include particularly uranium miners, but also groups of iron-ore and other metal miners, and one group of fluorspar miners. Strong evidence for exposure response relationships has been obtained from several studies, in spite of uncertainties that affect estimates of the exposure of the study populations to radon decay products. Several small case-control studies of lung cancer have suggested a higher risk among individuals living in houses known or presumed to have higher levels of radon and its decay products than among individuals with lower presumed exposure in houses. The evidence on the interaction of radon and its decay products with cigarette smoking with regard to lung cancer does not lead to a simple conclusion. The data from the largest study are consistent with a multiplicative or submultiplicative model of synergisms and reject an additive model. In many studies of miners and in one of presumed domestic exposure, small cell cancers accounted for a greater proportion than expected of the lung cancer cases. In one population of uranium miners, this proportion has been declining with the passage of time. Because of the limited scale of epidemiologic studies of nonoccupational exposure to radon decay products available at the time reviews were made, quantification of risk has been based only on data of miners’ experience. An IARC Working Group considered that the epidemiologic evidence does not lead to a firm conclusion concerning the interaction between exposure to radon decay products and tobacco smoking. Most of the epidemiologic studies involve small numbers of cases, and the analytical approaches for assessing interaction have been variable and sometimes inadequate.

HOW RADON ENTERS

Radon moving through soil pore spaces and rock fractures near the surface of the earth usually escapes into the atmosphere. Where a house is present, however, soil air often flows toward its foundation for three reasons: (1) differences in air pressure between the soil and the house, (2) the presence of openings in the house’s foundation, and (3) increases in permeability around the basement (if one is present).

In constructing a house with a basement, a hole is dug, footings are set, and coarse gravel is usually laid down as a base for the basement slab. Then, once the basement walls have been built, the gap between the basement walls and the ground outside is filled with material that often is more permeable than the original ground. This filled gap is called a disturbed zone.

Radon moves into the disturbed zone and the gravel bed underneath from the surrounding soil. The backfill material in the disturbed zone is commonly rocks and soil from the foundation site, which also generate and release radon. The amount of radon in the disturbed zone and gravel bed depends on the amount of uranium present in the rock at the site, the type and permeability of soil surrounding the disturbed zone and underneath the gravel bed, and the soil’s moisture content.

The air pressure in the ground around most houses is often greater than the air pressure inside the house. Thus, air tends to move from the disturbed zone and gravel bed into the house through openings in the house’s foundation. All house foundations have openings such as cracks, utility entries, seams between foundation materials, and uncovered soil in crawl spaces and basements.

Most houses draw less than one percent of their indoor air from the soil; the remainder comes from outdoor air, which is generally quite low in radon. Houses with low indoor air pressures, poorly sealed foundations, and several entry points for soil air, however, may draw as much as 20 percent of their indoor air from the soil. Even if the soil air has only moderate levels of radon, levels inside the house may be very high.

Because radon is a gas, it has much greater mobility than uranium and radium, which are fixed in the solid matter in rocks and soils. Radon can more easily leave the rocks and soils by escaping into fractures and openings in rocks and into the pore spaces between grains of soil.

The ease and efficiency with which radon moves in the pore space or fracture effects how much radon enters a house. If radon is able to move easily in the pore space, then it can travel a great distance before it decays, and it is more likely to collect in high concentrations inside a building.

The method and speed of radon’s movement through soils is controlled by the amount of water present in the pore space (the soil moisture content), the percentage of pore space in the soil (the porosity), and the “interconnectedness” of the pore spaces that determines the soil’s ability to transmit water and air (called soil permeability). 

Radon can move through cracks in rocks and through pore spaces in soils.  Radon moves more rapidly through permeable soils, such as coarse sand and gravel, than through impermeable soils, such as clays. Fractures in any soil or rock allow radon to move more quickly.

Radon in water moves slower than radon in air. The distance that radon moves before most of it decays is less than 1 inch in water-saturated rocks or soils, but it can be more than 6 feet, and sometimes tens of feet, through dry rocks or soils. Because water also tends to flow much more slowly through soil pores and rock fractures than does air, radon travels shorter distances in wet soils than in dry soils before it decays.

For these reasons, homes in areas with drier, highly permeable soils and bedrock, such as hill slopes, mouths and bottoms of canyons, coarse glacial deposits, and fractured or cavernous bedrock, may have high levels of indoor radon. Even if the radon content of the air in the soil or fracture is in the “normal” range (200-2,000 pCi/L), the permeability of these areas permits radon-bearing air to move greater distances before it decays, and thus contributes to high indoor radon.

PROPERTIES

Radon was discovered in 1900 by Friedrich Ernst Dorn, (Germany). Named after the element “radium” (radon was called niton at first, from the Latin word “nitens” meaning “shining”) but has been called radon since 1923. It is an essentially inert, colorless, odorless gas at ordinary temperatures. Its melting point is 202 degrees K and the boiling point is 211 degrees K. When cooled below the freezing point radon exhibits a brilliant phosphorescence which becomes yellow as the temperature is lowered and orange-red at the temperature of liquid air.

The atomic radius is 1.34 angstroms and it is the heaviest known gas, being nine times denser than air. Because it is a single atom gas (unlike oxygen, O2, which is comprised of two atoms) it easily penetrates many common materials like paper, leather, low density plastic (like plastic bags, etc.) most paints, and building materials like gypsum board (sheetrock), concrete block, mortar, sheathing paper (tarpaper), wood paneling, and most insulation.

Radon is also fairly soluble in water and organic solvents. Although reaction with other compounds is comparatively rare, it is not completely inert and forms stable molecules with highly electronegative materials. Radon is considered a noble gas that occurs in several isotopic forms. Only two are found in significant concentrations in the human environment: radon-222, and radon-220. Radon-222 is a member of the radioactive decay chain of uranium-238, and radon-220 is formed in the decay chain of thorium-232. Radon-222 decays in a sequence of radionuclides called radon decay products, radon daughters, or radon progeny. It is radon-222 that most readily occurs in the environment. Atmospheric releases of radon-222 results in the formation of decay products that are radioisotopes of heavy metals (polonium, lead, bismuth) and rapidly attach to other airborne materials such as dust and other materials facilitating inhalation.

Denver Radon Mitigation