What kind of radiation exposure is usually cumulative?

Low-level radiation exposure is considered to be cumulative because it generally refers to prolonged exposure to low doses of radiation over an extended period, which can lead to an accumulation of radioactive effects in the body. This type of exposure often occurs from sources such as background radiation, medical imaging, or occupational settings where individuals may be exposed to radiation over many years.

The cumulative nature of low-level exposure is significant in environmental health, as even small amounts of radiation can add up and increase the risk of long-term health effects, such as cancer. This contrasts with high-energy or acute radiation exposure, which may result in immediate effects but does not typically accumulate in the same way. Environmental radiation can also be cumulative but is more commonly discussed in terms of low-level exposure in terms of health impacts over time.

Thus, low-level radiation stands out as the correct answer due to its defining characteristic of being cumulative in the context of continuous, long-term exposure.