Many Florida buyers are surprised to learn that radon — a naturally occurring radioactive gas — is a consideration in Florida real estate. While South Florida's risk is generally lower than some other regions, testing is still recommended and can be important for your family's health.
What Is Radon?
Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil, rock, and water. It is colorless, odorless, and tasteless — you cannot detect it without testing. Radon can enter buildings through foundation cracks, gaps around pipes, and other openings. When radon accumulates in an enclosed space, long-term exposure increases the risk of lung cancer. Radon is the second leading cause of lung cancer in the United States (after smoking), according to the U.S. EPA.
Florida's Radon Risk Levels
The EPA divides the United States into three radon risk zones:
- Zone 1 (highest potential): Average indoor radon level above 4 pCi/L
- Zone 2 (moderate potential): Average indoor radon level 2–4 pCi/L
- Zone 3 (lowest potential): Average indoor radon level below 2 pCi/L
Most of Broward County and South Florida falls into Zone 3 — the lowest potential risk category. However, Florida also contains areas of Zone 2, particularly in north and central Florida. The EPA notes that even Zone 3 radon levels can occasionally exceed 4 pCi/L in individual homes, which is why testing is still recommended.
Florida also has a unique geological characteristic: phosphate deposits in central Florida can produce elevated radon. In South Florida, radon concerns are generally lower than in states like Pennsylvania, Iowa, or parts of the Midwest.
EPA Action Level
The EPA recommends taking action to reduce radon levels if testing shows 4 pCi/L or above. The EPA also recommends considering remediation at 2–4 pCi/L. The average indoor radon level in the U.S. is approximately 1.3 pCi/L; the average outdoor level is 0.4 pCi/L.
Radon Testing
Radon testing is simple and inexpensive:
- Short-term test (48–96 hours): A charcoal canister or electronic monitor is placed in the lowest livable area of the home. Most commonly used in real estate transactions. Costs $25–150 (DIY kit) or done by a licensed radon testing professional.
- Long-term test (90+ days): Alpha track detectors provide a more accurate average radon level. Better for understanding true annual average exposure.
For real estate transactions, short-term tests are most practical. They should be conducted with windows and doors closed for at least 12 hours before and during testing.
Radon Mitigation
If elevated radon levels are found, a radon mitigation system can reduce levels by 50–99%:
- Sub-slab depressurization (ASD): The most common mitigation system — a PVC pipe runs through the foundation slab to draw radon from beneath the home and exhaust it above the roofline. A fan maintains negative pressure. Cost: typically $800 to $2,500 installed by a licensed contractor.
- After installation, re-test to confirm levels are reduced below the action level.
Florida requires radon testing or mitigation contractors to be licensed by the Florida Department of Health. Verify licenses at floridahealth.gov.
Radon Testing in Florida Real Estate Transactions
Radon testing is not required by Florida law for residential real estate transactions. However, buyers have the right to test during the inspection period. Given the low cost of testing and the importance of long-term health, including a radon test with your home inspection is a reasonable precaution — even in South Florida's lower-risk zone.