What is the average indoor radon concentration in picocuries per liter (pci/l)?

The average indoor radon concentration is typically reported to be around 1.3 picocuries per liter (pci/l). This figure is significant because it reflects a median level found in homes across the United States. Understanding this average is crucial for radon mitigation specialists, as it serves as a baseline to assess whether a home's radon levels are elevated and potentially hazardous to health.

Radon, being a naturally occurring radioactive gas, can accumulate in spaces like basements and first floors, posing risks such as lung cancer with long-term exposure. Therefore, knowing that the average concentration is approximately 1.3 pci/l allows specialists to identify when mitigation methods may be necessary, as the U.S. Environmental Protection Agency (EPA) recommends fixing homes that have radon levels at or above 4.0 pci/l to reduce health risks.

The other options fall short of reflecting the commonly accepted average, making it important to recognize that 1.3 pci/l aptly represents a typical indoor environment. This knowledge is essential for professionals in the field when evaluating and addressing radon levels in homes.