Author: Masaharu Tsubokura
Editors: Akihiko Ozaki M.D., Yuki Senoo
183. Polonium is found in seafood
Owing to the achievements of scientists such as Becquerel, Curie, and Rontgen, radiation-related research has made significant advancements since the end of 19th century.
Various radioactive substances, such as radioactive potassium and uranium, are present in almost everything, including in our bodies, the soil, and the air. After the discovery of radiation from uranium by Henri Becquerel in 1896, various other radioactive substances have been discovered.
Marie Curie and her husband, Pierre Curie, discovered an ore that emits more radiation than metallic uranium. Later, they successfully extracted new radioactive substances called polonium and radium from the metal.
A high concentration of polonium is found in seafood. Since Japanese people consume a lot of seafood, it is known that we are exposed to a relatively higher level of radiation from seafood compared to the worldwide average. By the way, polonium was named after Poland, which was under the occupation of the Russian Empire at that time and the homeland of Curie.
184. The advancement of radiation-related research in the late 19th century
After Rontgen discovered X-rays in 1895, Becquerel discovered that radiation was emitted from uranium in 1896. Furthermore, in 1898, the Curies discovered a new radioactive substance called radium. With the remarkable accomplishments of many physicists, radiation-related research has made extensive progress since the late 19th century. Following the advancements of radiology, technology using radiation has been implemented in a variety of fields, such as medicine and agriculture.
On the other hand, it was known at an early point that radiation has adverse health effects on the human body. In 1896, the same year as Becquerel discovered the radioactivity of uranium, dermatitis caused by exposure to X-rays was reported. Following this report, general radiation protection principles were summarized in three key points (time, distance, and shielding) to protect hands from radiation. Furthermore, in the early 20th century, it was reported that skin cancer and leukemia were also associated with radiation exposure.
While radiation technology has progressed rapidly, knowledge of the health effects of radiation exposure accumulated through research and investigations. Based on current investigations, the concept of radiation protection, such as determining the upper limit of radiation exposure, has gradually developed and is still being improved.
The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, 16th and 22nd July 2018 was reproduced for MRIC Global under the author's permission.