What does the unit Bq/m^3 measure?

The unit Bq/m³, or becquerels per cubic meter, specifically measures the concentration of radioactive decay within a given volume of air. It indicates the number of radioactive decay events occurring per second in one cubic meter of air. This measurement is particularly relevant in the context of radon, a naturally occurring radioactive gas that can accumulate in buildings and pose health risks.

Understanding this unit is crucial for assessing radon levels in indoor environments. Radon measurement is typically expressed in Bq/m³ to effectively gauge the potential exposure risk to individuals. The higher the Bq/m³ value, the greater the concentration of radon and, subsequently, the likelihood of health impacts due to radioactive exposure.

The other options don't accurately reflect what the unit measures. The volume of radon in the atmosphere encompasses broader considerations than what Bq/m³ provides. Similarly, the amount of air in a cubic meter relates to physical volume rather than radioactivity, and the total mass of radon would require a different unit of measure, typically expressing mass rather than activity.