Abstract
Biological effects of neutrons are larger than those of low-LET radiation and those depend on their energy. Since, neutron sources such as accelerator, reactor and cosmic-rays must be taken into consideration to assess human risk from neutrons, the researches on wide range of neutron energy is needed. The critical accident occurred at 1991 in Japan caused necessity of researchs on biological effects of neutrons. While many researches had been conducted to assess biological effects of neutrons, especially carcinogenesis in experimental animal, details of mechanisms of them are still obscure. Since 2001, NIRS has started the biological effects research program on neutrons to evaluate two major subjects: relative biological effects (RBE) of neutrons for carcinogenesis and for effects on developing nervous systems in rodents. In this program, to investigate energy dependency of biological effects of neutrons cyclotron-derived fast neutrons (10MeV) are used and electrostatic accelerator-derived neutrons (~2MeV) will be available in the near future. In this symposium, we will present recent results obtained in our laboratory, and also discuss our future plans. [J Radiat Res 44:373-374 (2003)]
