The measurement of radioactivity is primarily conducted using instruments that detect and quantify ionizing radiation. The most commonly used units are the becquerel (Bq), which measures the rate of radioactive decay, and the sievert (Sv), which assesses the radiation dose absorbed by living tissue. Instruments such as Geiger-Müller counters and scintillation counters are frequently employed for detecting alpha, beta, and gamma radiation. These devices provide valuable data that toxicologists use to evaluate potential health risks.