Fukushima's tritiated water discharge: Health and environmental implications derived from historical nuclear incidents

The Fukushima disaster is the first major nuclear accident to occur along a coastline. It sparked concern about the global dispersion of radionuclides via oceanic currents. The decision to discharge Fukushima tritiated water into the Pacific Ocean further intensified concern and criticism, despite endorsement by the International Atomic Energy Agency (IAEA). The discharged water contains tritium concentrations well below international drinking water standards. The IAEA has verified the safety of the water and continues to oversee the discharge process to minimize potential harm to human health and marine ecosystems. Tritium, by contrast, is a naturally occurring radionuclide, and its controlled release from nuclear facilities is a globally accepted and long-standing practice. Alongside natural and controlled emissions, a massive amount of tritium was released into the environment during nuclear weapons testing in the 20th century—hundreds of times greater than the current global residual inventory. As a result, both human populations and ecosystems have historically been exposed to substantial levels of tritium without definitive evidence of adverse effects. This study reviews the risks of tritiated water in the context of major nuclear events and emphasizes its significantly lower internal dose contribution than naturally occurring radionuclides such as carbon-14 and potassium-40. It compares tritium's physical characteristics, biological behavior, and effects on human health with those of key radionuclides. Drawing on scientific evidence and empirical data from widespread nuclear testings, the Chernobyl and Fukushima disasters, and regions with naturally high background radiation, this study finds no discernible risk at the current FDNPP discharge rate and argues that the controlled release of tritiated water poses negligible—possibly non-existent—risk to human health and the environment.