Source: image; David Ropeik

You may have heard that the government of Japan has approved the release of 1.25 million tons of wastewater collected on the site of the Fukushima-Daichi nuclear complex since the accident there in 2011. On the scientific evidence, this release poses as close to zero risk to human or environmental health as any risk ever gets. But on the optics — the emotions — here we go again with “OMG! It's radioactive!” That OMG carries its own dangers. It’s worth examining.

The Science

The water was pumped over three melted nuclear reactors to keep them from overheating, then collected and filtered to remove anything that might be considered a pollutant, except for radioactive tritium, which is an unstable molecular version of H20 — water — and can't be captured by filtration. Tritium is a weak type of radioactive particle. It poses a tiny risk even if you ingest high levels, and the levels in the 1,020 (and growing) storage tanks are very low. The plan is to filter the water again to capture any other radioactive elements it may still contain, and slowly release it into the ocean, over four decades, so the dose of tritium in the water released will be one-fortieth of the dose allowed in drinking water in Japan, and one-seventh the level allowed by the World Health Organization.

The International Atomic Energy Agency notes that this is “in line with practice globally.” Nuclear plants are permitted to release low amounts of tritium in their cooling water at levels below carefully researched safety thresholds. (Sometimes there are un-permitted pipe leaks.) Despite alarms from environmental groups, extensive research has never associated these releases with any harm to human or environmental health.

Tritium also forms naturally in the upper atmosphere and tiny levels literally rain down on us all the time. It’s also in some of those glow-in-the-dark EXIT signs in theaters, at levels way higher than in the Fukushima storage tanks.

The Optics/Emotions

The South Korean government said, “The decision can never be accepted and would cause danger to the safety and maritime environment of neighboring countries.” The Chinese government called the decision “extremely irresponsible” and said that “The leak of large amounts of radioactive materials (from the Fukushima accident) has had far-reaching implications on the marine environment, food safety, and human health.” It’s worth noting that both countries have nuclear power programs that regularly emit low levels of tritium into cooling water. As do Russia and Taiwan, both of which expressed “serious concern."

Some environmental groups sounded alarms. Greenpeace called the action an “unjustified decision to deliberately contaminate the Pacific Ocean with radioactive wastes.” Protestors in Japan called it “nuclear terrorism” and, wearing contamination protection clothing outside a government office, waved signs with various types of fish bearing the ominous radioactive warning radura.

Social media messages from South Korea and China included alarms like "Fukushima water could destroy half the Pacific Ocean in 57 days" and "Japan is inflicting a disaster on other nations." Many called for a mass boycott of Japanese seafood, citing worries of "high radioactive content" in fish imported from Japanese suppliers. People in the fishing business along the northeast coast of Japan, whose catch has been inspected in government labs ever since the accident with no evidence of contamination, are still struggling from decreased demand, complain about a decision they worry will make things worse.

The Science Behind the Optics/Emotions

Radiation has been a scary word since the atomic bombings of Japan, the atmospheric testing of nuclear weapons (that raised tritium levels in rainfall globally), and the rise of the environmental movement that used the potential cancer risk of radiation to successfully get that atmospheric testing stopped. (It was fear of radioactive fallout that inspired Rachel Carson in Silent Spring to raise similar alarms about the indiscriminate use of chemical pesticides.)

But it scares us for more intrinsic psychological reasons. We are more afraid of any risk we can’t detect with our own senses, more afraid of any risk imposed on us than if we engage in it voluntarily (you get more ionizing radiation in airplane travel than this tritium release might expose you to… but then, you choose to travel), more afraid of risks that are human-made than if they’re natural (tritium in rainfall = no problem), and more afraid of risks that cause greater pain and suffering… as cancer often does. We are also more afraid when we don’t trust the people or government agencies we count on to protect us… and the Japanese government’s poor risk communication during the Fukushima accident badly eroded that trust.

The scientific evidence on the psychology of risk perception refutes those who call fear of radiation “irrational.” It may not match the evidence — and to be fair who among us has all that evidence anyway — but given the tools we’ve evolved to gauge potential danger, radiophobia makes sense as we try to keep ourselves safe. This is why Professor Hirohiko Fukushima of Chuo Gakuin University in Japan wisely summarized the issue this way: “Japan is in a battle to alter perceptions, whether of the trustworthiness of its own government or of the risk posed by the treated water.” And why Associate Professor Eunjung Lim of Kongju National University in South Korea was shrewd to observe “whether their worries are rational or not, many people in the region are going to be very, very anxious.”

The worry is real. And that worry is in fact the real threat. Fear that doesn’t match the evidence can cause problems too. We could use more nuclear power to help combat climate change, but radiophobia is why that form of energy is not considered “clean” the way solar and wind are, even though like those sources nuclear emits no greenhouse gas emissions or particulate pollution. Political opposition remains to the installation of cell phone towers and power lines and smart meters on homes and businesses that help reduce energy consumption, all because of radiophobia, an excessive fear that flies in the face of the evidence and does real harm too.

So the Fukushima water release issue provides an opportunity; to recognize that our perceptions of risk, though they make sense because they help us feel safe, are sometimes a threat all by themselves. And just as we should rightly be cautious about the physical risks that worry us, we need to apply some caution to the emotional way we instinctively respond to those risks, if we want to do the smartest job of keeping ourselves safe.