Sieverteissä

Sieverteissä is the inessive plural form of the Finnish word sievert, the SI unit used to express radiation dose in terms of biological effect. The form is used when measurements are given in sieverts and multiple values are discussed, for example in reports detailing doses recorded at several locations or times.

The sievert (Sv) quantifies the radiation dose equivalent or effective dose. It is derived from the absorbed dose, measured in gray (Gy), by multiplying by dimensionless radiation weighting factors that reflect how different radiation types affect biological tissue and by tissue weighting factors that emphasize the sensitivity of different organs. The resulting quantity enables comparison of potential health risks from different radiation exposures. Historically, the sievert is defined so that 1 Sv equals 100 rem; today the rem is rarely used in scientific contexts.

Compared with gray: Gray measures energy deposited per kilogram, while sievert translates that energy into a biological risk. For the same physical dose, high-LET radiation such as alpha particles yields a higher dose in sieverts than low-LET radiation like X-rays. For example, 1 Gy of alpha radiation is often associated with about 20 Sv for the radiological effect, depending on context and weighting factors.

Usage: Doses are usually expressed in Sv or more commonly in millisieverts (mSv). Natural background radiation is roughly 2–3 mSv per year; occupational exposure limits commonly cap at 20 mSv per year on average, with possible higher single-year limits (up to 50 mSv) in some jurisdictions. Public exposure limits are typically around 1 mSv per year.

Note: The term sieverteissä appears mainly in Finnish writing when listing multiple measurements within the unit; the everyday usage is often to speak of a value in sieverts rather than the plural form.