What is radon?

Radon is a radioactive gas - that means it continuously decays and releases radiation. It is produced from minerals in soil, such as uranium and radium.

Although radon is present throughout the environment, when high levels are present indoors people are exposed to more of its radiation and their risk of cancer increases. Such a situation can be discovered easily and corrected.

How does radon enter a home?

Radon, because it is a gas, is able to move though spaces in the soil or fill material around a home's foundation. Most homes tend to operate under a negative pressure - this is especially true in the lowest portions of the home and during the heating season. This negative pressure acts as a vacuum (suction) that pulls soil gases, including radon, into the lower level of the structure. Some causes of home vacuum are:

• Heated air rising inside the home (stack effect).
• Wind blowing past a home (downwind draft effect).
• Air used by fireplaces, wood stoves, and furnaces (vacuum effect).
• Air vented to the outside by clothes dryers and exhaust fans in bathrooms, kitchens, or attics (vacuum effect).

Radon can enter a home through the floor and walls -- anywhere there is an opening between the home and the soil (see list of Major Radon Entry Routes below). Examples of such openings include dirt floor crawl spaces, unsealed sumps, cracks in slab-on-grade floors, utility penetrations, and the tiny pore spaces in concrete block walls. A basement, of course, provides a large surface area that contacts soil material.

Major Radon Entry Routes

1. Cracks in concrete slabs.
2. Spaces behind brick veneer walls that rest on uncapped hollow-block foundations.
3. Pores and cracks in concrete blocks.
4. Floor-wall joints.
5. Exposed soil, as in a sump or crawl space.
6. Weeping (drain) tile, if drained to an open sump.
7. Mortar joints.
8. Loose fitting pipe penetrations.
9. Open tops of block walls.
10. Building materials, such as brick, concrete, rock.
11. Well water (not commonly a major source in Welsh homes).

What happens after radon gets into the home?

Once radon enters a home it moves freely throughout the indoor air and people can breath it into their lungs. Understanding how it distributes through the home environment can help explain why timing and location are important factors to consider when conducting a radon test.

The level of radon is often highest in the lower part of the building. Radon moves through a house by diffusion and natural air movements and it can be distributed by mechanical equipment such as a forced-air ventilation system. As radon moves away from the home's foundation or other entry points, it mixes (and is diluted) into a greater volume of air. In addition, more dilution often occurs in the upper levels of the home because there is more fresh air ventilation there.

Greater dilution and less house vacuum may also occur when the house is more open to the outdoors during the non-heating season. This generally results in lower indoor radon levels in the summer compared to the winter.

How can I find out if my home has a radon problem?

Radon is colourless, odorless and tasteless. Therefore, a radon test is the only way to find out how much radon is in your home. RPW Radon Wales recommends that all homeowners have their homes tested for Radon. Every home is unique due to its local soil, construction details, maintenance and degree of depressurisation. Therefore, test results from nearby homes cannot be relied upon to predict the radon level in another home. Likewise, previous test results may not reflect current and future radon levels for a home that has been remodeled, weatherised or had changes made to its heating, air conditioning or other ventilation and heating systems.

The results of a properly and professionally performed radon test will help homeowners determine for themselves if they need to take further action to protect their family from the health risks of radon in the home.

Contact RPW Radon Wales by telephoning 07977 414447, by filling in an online contact us form or emailing enquiries@rpwradonwales.co.uk.