General Radon Information

South Carolina specific radon and radon level information can be found throughout this site. You will be able to find information about certified radon inspectors in South Carolina, as well as detailed radon level information for every county in South Carolina.

Radon is a radioactive, colorless, odorless, and tasteless gas. It is formed as natural deposits of uranium throughout the earth’s crust decay. As radon decay products are inhaled, they can alter the cells in the lungs. These alterations can increase the potential for getting lung cancer. Radon is the second leading cause of lung cancer behind smoking. An estimated 14,000 people die of radon related lung cancer each year.

The amount of radon in a building is dependent upon several factors. These factors include the geology, a driving force, pathways into the building, and the ventilation rate. As the concentration of uranium is in the underlying soil increases, so does the strength of the radon. Radon is transported to buildings more easily through permeable soils. Buildings can create pressure differentials that will draw in the soil gases. Radon can enter the building through many paths such as cracks in the foundation, utility penetrations, sumps, and floor drains. The ventilation rate of the building affects the final radon concentration.

EPA has made the recommendation of no long-term radon exposures above 4 pico couries/liter (pCi/L). This action level was based on both health and economics. The only way to tell if a building has elevated levels of radon is to have it tested.

Any home can have a radon gas problem. Homes can trap radon inside. Over time, it builds up. How does radon enter your home? Houses act like large chimneys. As the air in the house warms, it rises to leak out the attic openings and around the upper floor windows. This creates a small suction at the lowest level of the house, pulling the radon out of the soil and into the house. You can test this on a cold day by opening a top floor window an inch. You will notice warm air from the house rushing out that opening; yet, if you open a basement window an inch, you will feel the cold outside air rushing in. This suction is what pulls the radon out of the soil and into the house. You might think caulking the cracks and the openings in the basement floor will stop the radon from entering the house. It is unlikely that caulking the accessible cracks and joints will permanently seal the openings radon needs to enter the house. The radon levels will still likely remain unchanged. All houses should be tested for radon, if not during the sale or purchase, at least after you take occupancy. Even houses in areas of low radon potential can have elevated radon levels. The probability of course is less in low radon potential areas but it doesn't matter what the probability is if your house is the one that has high radon.

The SC Radon Zones map shows areas in SC with the highest chance for radon. If radon is breathed in, it can change the cells in the lungs. These changes can increase the chances for getting lung cancer. The World Health Organization, the U.S. EPA and the U.S. Department of Health and Human Services' National Toxicology Program have all concluded that radon is a known cancer-causing agent in humans. The National Academy of Sciences' Biological Effects of Ionizing Radiation VI Report (1998) concluded that radon causes between 15,000 and 22,000 lung cancer deaths each year in the United States. The U.S. Surgeon General has warned that radon is the second-leading cause of lung cancer in the United States - second only to smoking. For nonsmokers in this country, radon is the No. 1 cause of lung cancer.

The EPA conducted a nationwide survey and found that approximately 1 in every 15 homes in the U.S. have problems with radon. However, typically in geographic areas with more rocky sub-strata (like the SC upstate), the percentages are closer to 1 in 7 homes. The EPA recommends that every house be tested for radon because elevated levels have been encountered in all 50 states!

The potential for actually getting lung cancer from radon is dependent upon how "high" your radon level is and how much time you spend in your home. The "air tightness" and air communication in each house is also different so the only way you will know if your home has a problem is to have it tested.

Testing for radon is easy and relatively inexpensive. Two standard methods exist for testing a home for the presence of radon gas. Short-term testing methods are designed to provide a quick radon value. Short-term tests can be as short as 48 hours and as long as 90 days. Long-term testing methods are designed to provide an annual average of radon gas. Long-term tests run for a minimum of 90 days, and usually for 6 to 12 months. If elevated levels of radon are found, steps may be taken that will safely and effectively reduce the radon level in your home to within EPA recommended norms (under 4 picocuries).