How has RERF research of the A-bomb survivors and their children helped the world? We think the answer to that question can be summarized in the following two ways.
One way is that RERF has clarified the effects of radiation on human health. We have accumulated a wealth of knowledge about radiation health effects over a span of about 70 years, since the start of our research. For example, we know that A-bomb survivors have higher cancer-incidence and mortality rates than the unexposed. Incidence of solid cancers (defined as all cancers except leukemia) began to increase about 10 years after the exposures and continues its rise today. In addition, lifetime risk of dying from cancer by age 70 for people exposed to around 100 mSv at age 30 is about 21% on average for men and women, compared to 20% for unexposed individuals—a 1% increase.
According to our research of A-bomb survivors, it is now known that people have a higher cancer risk the younger they were at the time of exposure (except for lung cancers). However, many aspects of the mechanisms behind how radiation is involved in cancer development remain largely unknown, and thus further research into this topic is necessary. With future mechanistic studies in mind, biosamples such as blood and urine collected with consent from A-bomb survivors and their children are essential. And, such biosamples exist only in Hiroshima and Nagasaki.
The second way is in the creation of global standards used to protect people from radiation exposure. In modern society, we are exposed to radiation in a variety of places. The most common location are hospitals, which typically have special rooms to house radiation equipment used in examination and treatment. However, the general public also moves through hospital corridors, for example, just outside these rooms. For that reason, strict controls are placed on radiation emitted from the areas, in accordance with government regulatory standards, allowing anyone to safely pass by hospital rooms where radiation is used. To create such standards designed to protect people from radiation, it is necessary to accurately understand true radiation risks. RERF’s research results from A-bomb survivors and their children are used to this end.
Information about the relationship between exposure doses and disease risks obtained from this research is verified and recorded by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Next, based on this risk information, the International Commission on Radiological Protection (ICRP) provides recommendations to international organizations and national governments about how to handle radiation protection. In response to ICRP’s recommendations, all countries, including Japan, create radiation protection standards appropriate for their own situations and, based on these standards, manage radiation within their own borders.
These standards are used not only in the aforementioned case of management of medical irradiation in hospitals. They have also been used to protect nuclear workers, nuclear emergency workers, and even the general public from radiation in Fukushima, the location of the 2011 nuclear accident.
As can be understood from the above, RERF’s research has a global reach in terms of both scientific insight and health protection.