What are the common units for measuring radiation?

Common units for measuring radiation include becquerels, grays, sieverts, and rads.

Radiation is energy emitted from a source, and it can be measured in different ways depending on what aspect of the radiation you are interested in. The becquerel (Bq) measures the activity of a radioactive source, specifically the number of decays per second. For example, if a sample has an activity of 1 Bq, it means one atom in the sample decays every second.

The gray (Gy) is used to measure the absorbed dose of radiation, which is the amount of radiation energy absorbed per kilogram of matter. One gray is equivalent to one joule of radiation energy absorbed by one kilogram of matter. This unit is particularly important in medical contexts, such as radiotherapy, where precise doses of radiation are used to treat cancer.

The sievert (Sv) is a unit that measures the biological effect of radiation. It takes into account not just the absorbed dose (measured in grays) but also the type of radiation and its impact on different tissues. For instance, 1 Sv of alpha radiation has a different biological effect compared to 1 Sv of gamma radiation. This unit is crucial for assessing the risk of radiation exposure to humans.

Lastly, the rad is an older unit of absorbed dose, where 1 rad is equal to 0.01 gray. Although it is less commonly used today, you might still encounter it in some contexts, especially in older literature or in the United States.

Understanding these units helps us to analyse and manage the effects of radiation in various fields, from medical treatments to nuclear power and environmental safety.