The equivalent dose that accounts for the different biological effects of different radiations is measured in

Explanation

The sievert multiplies the absorbed dose in grays by a quality factor, which is 1 for beta and gamma but about 20 for alpha particles, because alpha deposits its energy in a very short track and does far more local damage. Legal exposure limits for workers and the public are therefore set in millisieverts. The becquerel describes the source rather than the dose received.