On May 6th 1896 Rolf Maximilian Sievert was born in Stockholm Sweden. Sievert devoted his life to the measurement and medical usage of ionizing radiation. His invention of the Sievert chamber for consistent measurement of radiation dosage helped pave the way for the safe control of ionizing radiation in medical applications. In recognition of his achievements, the SI unit for equivalent dose and efficient dose was designated the sievert, Sv, in 1979.
Professor Rolf Sievert worked with many organizations on radiation protection issues including the Swedish Radiation Protection Institute (SSI), the International Commission for Radiological Protection (ICRP) and, the International Commission for Radiation Units and Measurements (ICRU, Chairman 1956 to 1962).
For further reading:
Biography – Wikipedia
SI Unit the Sievert – Wikipedia
Rolf Sievert, the man and the unit – Karolinska Institutet
Radiobiology
BBC – h2g2 – The Measurement of Radioactivity
Paul Hutchinson's Blog 