The sievert (Sv) is a unit of measurement used to quantify the biological effects of ionizing radiation on human health. It helps assess the potential risk of radiation exposure by considering both the amount of radiation absorbed and its impact on different types of tissues. One sievert represents a significant dose of radiation that can lead to health issues, including radiation sickness or increased cancer risk. For practical purposes, smaller doses are often expressed in millisieverts (mSv), where 1 Sv equals 1,000 mSv, making it easier to discuss everyday exposure levels, such as those from medical procedures or environmental sources.