What unit of measurement is used for Radon concentration?

Radon concentration is commonly measured in becquerels per cubic meter (Bq/m³) or picocuries per liter (pCi/L). The unit of measurement that reflects a standard practice for radon concentration in many countries, including guidance from health organizations, is the becquerel per cubic meter. One becquerel corresponds to one disintegration per second, making it a valuable unit in the context of radioactive measurement and providing a direct sense of the activity level of radon in the air.

The choice of 37 Bq/m³ is particularly significant because it corresponds to the radon concentration of 1 pCi/L, establishing a direct conversion factor between the two units. The accuracy and relevance of becquerels in capturing radon levels make this answer the most suitable in the context of radon measurement practices.

While the other options present numbers in picocuries or higher briskly moving into millecuries, these are less common in routine radon concentration analysis and tend to represent higher levels of radioactivity—often more suited for different applications or less frequent in residential environments where radon measurement is prioritized.