Radon is a radioactive gas that comes from the decay of radium in the soil. Radium is a decay product of uranium. Uranium is present in almost all rocks and soil and material derived from rocks. Radon is a colorless, odorless, invisible gas that occurs naturally. Chronic exposure to elevated radon levels has been linked to an increased incidence of lung cancer in humans.
Yes. For most people, radon is their largest source of exposure to nuclear radiation. The US Environmental Protection Agency (EPA) has identified radon as the second
leading cause of lung cancer in the United States. Many homes, contain radon concentrations that are high enough to give their occupants lifetime exposures of the same size as those received by
underground miners who showed the increased risk of lung cancer mortality. When radon and its decay products are inhaled into your lungs they emit energetic particles called alpha particles. These
alpha particles can strike the sensitive lining of the bronchi. When this happens, the cells in your lungs are
damaged, subsequently increasing your risk of developing a cancer. Most of the alpha particle radiation comes from radon decay products. People usually characterize their exposure to this radiation damage by the amount of radon in their living spaces since it is easier to measure radon rather than energy that radon decay products deposit in the lung tissues.
Radon gas typically moves up through the ground to the air above and into your home through cracks and other holes in the foundation. Your home traps radon inside, where it can build up. Any home may have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements.
Radon gets in through:
- Cracks in solid floors
- Construction joints
- Cracks in walls
- Gaps in suspended floors
- Gaps around service pipes
- Cavities inside walls
- The water supply
also be dissolved in water, particularly well water. After coming from a faucet, about
one ten thousandth of the radon in water is typically released into the air. The more radon there is in the water, the more it can contribute to the indoor radon level.
Your house type will affect the kind of radon reduction system that will work best. Houses are generally categorized according to their foundation design. For example: basement, slab-on-grade (concrete poured at ground level), or crawlspace (a shallow unfinished space under the first floor). Some houses have more than one foundation design feature. The right radon reduction system depends on the design of your home and other factors.
In many cases, simple systems using underground pipes and an exhaust fan may be used to reduce radon. Such systems are called "sub-slab depressurization," and do not require major changes to your home. These systems remove radon gas from below the concrete floor and the foundation before it can enter the home. Similar systems can also be installed in houses with crawl spaces.
Sealing cracks and other openings in the floors and walls is a basic part of most approaches to radon reduction. Sealing does two things, it limits the flow of radon into your home and it reduces the loss of conditioned air, thereby making other radon reduction techniques more effective and cost-efficient. The EPA does not recommend the use of sealing alone to reduce radon because, by itself, sealing has not been shown to lower radon levels significantly or consistently. It is difficult to identify and permanently seal the places where radon is entering. Normal settling of your house opens new entry routes and reopens old ones.
Source - Environmental Protection Agency (EPA)