Tokyo must keep in mind wastewater dumping is global issue

The Japanese government said the 1.25 million metric tons of contaminated water it will release into the Pacific Ocean over the next 30 years or so will be diluted more than 100 times using seawater. It said this will ensure that the tritium in the water will be one-fortieth of the national drinking water standard, or one-seventh of the World Health Organization's standard.

But this statement needs a transparent scientific basis. If dilution is safe and easy, people may wonder why Japan would wait until now to deal with it.

Japan announced on Tuesday the decision to dump the contaminated water from the tsunami-crippled Fukushima Daiichi nuclear plant, with releases to begin in two years.

The decision has been met with strong skepticism and opposition at home and abroad. The main reason is that Japan's decision is not based on technological progress regarding nuclear wastewater treatment, but rather because its existing storage capacity for nuclear wastewater could last for less than two years. Another reason is that the Japanese government plans to start decommissioning the Fukushima Daiichi nuclear power plant in two years.

The discharge of radioactive water is closely related to the quantity of nuclear radiation and the kind of nuclear radiation material it contains. There is great uncertainty about the speed, scope and impact of its diffusion and dilution, but one thing is sure: the wastewater will move a large distance with ocean currents and marine organisms, which may directly or indirectly affect the surrounding countries and the whole marine ecosystem.

The US State Department issued a statement on its website after the Japanese government officially announced the decision, expressing understanding and disguised support. However, the radioactive water that will pour into the sea from Fukushima will eventually reach US shores across the Pacific Ocean. The extent of its impact remains to be determined by scientific research.

The United Nations Convention on the Law of the Sea stipulates that "states have the obligation to protect and preserve the marine environment", and urged that all necessary measures be taken to avoid cross-border environmental disasters. The convention also says that when a state becomes aware of imminent danger to the marine environment, "it shall immediately notify other states it deems likely to be affected by such damage", as well as relevant international organizations.

Therefore, Japan must consider the harm to the marine environment, food safety and human health caused by the discharge of a large amount of nuclear wastewater containing radioactive substances such as tritium, in order to avoid man-made marine environmental disasters. It should report the process and results of treatment in an open, transparent and scientific manner and accept the third-party supervision of international organizations such as the International Atomic Energy Agency and relevant countries, so that the world can know whether the radioactivity of the water from Fukushima has been reduced to a safe level.

Japan is also a victim of contaminated nuclear water. After so many years of effort, the fishing industry around Fukushima is just beginning to return to normal, so fishermen and groups involved in the industry around Fukushima are among the most vocal opponents. They worry that renewed damage from rumors of nuclear contamination could ruin their efforts over a decade to restore the region's image after the nuclear plant disaster.

The Japanese government conducted talks last year with JF Zengyoren, a nationwide federation of Japan's fisheries cooperatives, Fukushima's local fisheries association and the local government, but failed to reach a consensus.

The decision announced on Tuesday "is extremely regrettable and totally unacceptable", Hiroshi Kishi, president of JF Zengyoren, said in a statement on Tuesday, adding that "this is an act that tramples on the feelings of fishermen not only in Fukushima prefecture but also in the rest of Japan."

Some local fishing associations also have expressed their distrust to Tokyo Electric Power Co, owner of the Fukushima plant, saying they wondered whether the water pollution purification equipment was even operating normally.

Contaminated water treatment is indeed a world problem. Discharging into the sea is one of two options－the other being vapor release－recommended by a panel of Japanese experts and considered more economical and technically feasible.

In a sense, Japan is taking the lead in handling this global problem. On the issue of nuclear power safety, humankind should be a community with a shared future where benefits and risks are shared.

The author is a professor at the College of Policy Science at Ritsumeikan University and director of the Research Institute of Global 3E in Japan.