Dr. Tsubokura's Radiation Lecture Vol.90
Author: Masaharu Tsubokura
Editors: Akihiko Ozaki M.D., Yuki Senoo
179. Units of measure and elements are often named after physicists
There are many types of technical terms in the field of radiation, such as Becquerel, Sievert, and X-ray (In Japanese, X-rays are called Roentgens). Many of these words are derived from the names of scientists who made significant contributions to radiation-related research.
The Becquerel (Bq) is a unit of radioactivity, which is the ability of radioactive substances to emit radiation. Simply put, it represents the number of radioactive substances. Therefore, Becquerels are used with regard to an object that exhibits radioactivity, such as food or soil.
In 1896, Henri Becquerel, whose family has been studying fluorescent materials for three generations in Paris, was planning to conduct an experiment using sunlight when he discovered radioactivity by accident. Becquerel had to postpone the experiment for several days due to cloudy weather, and he put photographic film into a desk drawer together with a piece of uranium, both of which he intended to use in the experiment. A few days later, he noticed that the photographic film had developed, even though it had been in the drawer and not directly exposed to sunlight.
This was the moment that the radioactivity of uranium—in other words, the fact that radiation emitted from uranium was hitting the photographic film—was discovered. Later on, Curie named this ability of uranium “radioactivity.” For their achievement, Henri Becquerel and the Curies received the Nobel Prize in Physics in 1903.
180. The Sievert is a unit showing radiation’s effects on the human body
There are many types of technical terms in the field of radiation, such as Becquerel, Sievert, and X-ray (In Japanese, X-rays are called Roentgens). Many of these words are derived from the names of scientists who made significant contributions to radiation-related research.
The Sievert is a unit of radiation exposure in a human body. This unit is used with regard to human bodies that have been exposed to radiation. For instance, it is used to represent the effects of ingested food on health or to measure the health effects of spending time in an area with a certain air dose rate.
Rolf Maximilian Sievert, a Swedish physicist, was known for his accomplishments in studying the effects of radiation on the human body, particularly regarding radiation protection. The name Sievert was used to develop radiation protection measurements based on the estimated effects of radiation on the human body and to compare the severity of adverse health effects of radiation with other health risks.
Sievert was the key person in establishing the Swedish Radiation Observation Network, which detected the Chernobyl nuclear accident and informed the rest of the world about it before the former Soviet government announced the accident.
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The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, 17rd and 24th June 2018 was reproduced for MRIC Global under the author's permission.