It’s been ten years since the devastating 9.0 magnitude Tōhoku earthquake and its subsequent 46 foot-tall tsunami killed more than 18,000 people, obliterated entire towns, and crippled the Fukushima Daiichi nuclear power plant on Japan’s eastern coast. As the incident unfolded in March, 2011, the stricken power plant released massive amounts of cesium-137 into the surrounding environment (roughly 80 percent of the material running into the Pacific ocean) and continued to pour out around 30 gigabecquerel of cesium-137 and strontium-90 for the next two years. And, as of 2018, around 2 gigabecquerel of radioactive pollution still manages to escape the site daily.
Now, as a decommissioning project that is expected to take a generation to complete enters its second decade, Japan’s government announced a controversial decision regarding the site’s continued cleanup. The government reportedly has approved a plan to dump more than a million tons (~250 million gallons) of seawater treated with the Advanced Liquid Processing System which has been stored at the Fukushima site into surrounding Japanese waters. This water has been stored in a series of 1,000 submerged metal tanks holding the equivalent to 500 Olympic sized swimming pools, which have been built out of over the years as increased capacity has become necessary. Problem is, the site is running out of space so the plan is to slowly release the treated water, gradually diluting it into the surrounding seas over the course of 20 to 30 years. Really, what could go wrong with a plan to release radioactively contaminated liquids — despite being stringently purified — into the open ocean? Perhaps not as much as we’d initially feared.
“Disposing of the treated water is an unavoidable issue in decommissioning the Fukushima Daiichi plant,” Prime Minister Yoshihide Suga told reporters during a recent news conference. The proposed action would not take place for at least two more years, but it has already prompted outcries from both Japan’s domestic fisheries and its international neighbors.
“Seeing this decision being made is completely outrageous and it is something we absolutely cannot accept. We will strongly protest,” Hiroshi Kishi, president of a nationwide federation of Japanese fishery co-ops, said in a response statement. A spokesperson for China’s foreign ministry went even further after Japanese Deputy Prime Minister, Taro Aso, asserted the treated water was safe to consume. “The ocean is not Japan’s trash can,” spokesperson Lijian Zhao challenged. “It should not expect the world to pay the bill for its treatment of wastewater. The Japanese official said the water is okay to drink, why doesn't he take a sip first?”
“The Japanese government has once again failed the people of Fukushima,” Greenpeace campaigner Kazue Suzuki, said in a statement. “The government has taken the wholly unjustified decision to deliberately contaminate the Pacific Ocean with radioactive wastes. It has discounted the radiation risks and turned its back on the clear evidence that sufficient storage capacity is available on the nuclear site as well as in surrounding districts. Rather than using the best available technology to minimize radiation hazards by storing and processing the water over the long term, they have opted for the cheapest option, dumping the water into the Pacific Ocean.”
“Given that the Fukushima nuclear power plant is on the ocean, and with leaks and runoff directly to the ocean, the impacts on the ocean will exceed those of Chernobyl, which was hundreds of miles from any sea,” Ken Buesseler, senior scientist at the Woods Hole Oceanographic Institution, said as the situation unfolded in 2011. “My biggest concern is the lack of information. We still don’t know the whole range of radioactive compounds that have been released into the ocean, nor do we know their distribution. We have a few data points from the Japanese — all close to the coast — but to understand the full impact, including for fisheries, we need broader surveys and scientific study of the area.”
“We haven't yet seen enough data to assess what's going on, so anything that can be done in terms of further monitoring would be very welcome,” he continued.
During the initial months of the nuclear meltdown, monitoring agencies saw extensive releases of iodine-131 and cesium-137. In 2011, the Tokyo Electric Power Company (TEPCO) reported that seawater sampled near the site contained 5 million times the legal limit of iodine-131 and around 1 million times the legal level of cesium-137. While the iodine dissipated quickly thanks to a 8-day half life, the cesium (with a 30-year half life) has stubbornly persisted in the waters off of Fukushima Bay. However, its continued presence may not end up being the apocalyptic ecological event biologists and marine initially feared.
Besides the immediate concerns of a mass die-off caused by acute radiation poisoning (which thankfully did not come to pass) researchers feared the long-term impacts of chronic cesium-137 exposure once the radioactive materials entered the food chain. A marine survey conducted in June of 2011 and published in PNAS that December announced that it had detected found cesium through nearly all of the offshore marine waters out to 600 km and found evidence of of its uptake (as well as that of silver-110) into zooplankton as well as mesopelagic fish.
A 2013 study from the World Health Organization failed to find an observable increase in local cancer rates immediately following the meltdown. And, in 2016, Jordi Vives i Batlle of the Belgian Nuclear Research Centre published a study in the journal Integrated Environmental Assessment and Management, found that radiation levels within the Fukushima fauna were actually lower following the incident than initially predicted. “Exposures were too low for acute effects at the population level to be observed in marine organisms,” the study’s researchers wrote. Furthermore, a follow-on study from this past March found that, to date, local residents had suffered “no adverse health effects” due to the 2011 incident’s fallout. The Chernobyl disaster, on the other hand, killed 31 people in the initial aftermath due to exposure to radiation and thermal burns and has been linked to nearly 20,000 documented cases of thyroid cancer among those exposed in a 2018 UNSCEAR report.
“All life has existed — even before humans appeared on this planet — on a radioactive planet in a radioactive universe,” Dr. Nicholas Fisher, Director of the Consortium for Interdisciplinary Environmental Research at Stony Brook University, noted to Engadget. “You were born radioactive, and you are radioactive right now. I am radioactive just as much as you are. I drank radioactive water this morning for breakfast, as did you. The radioactivity in your body is all natural.”
“Now, there are some bodies of water that have received very high levels of radioactivity from human activities,” Fisher explained. “Fukushima Bay, the Irish Sea, which has received radioactive wastes from the [now-closed] Sellafield nuclear fuel reprocessing plant.” Of course, the Fukushima incident is notable as it is currently “the single largest accidental release of radioactivity into the oceans,” Fisher points out.
Of all the radiation present in the oceans today, Fisher estimates that only between 1 and 2 percent of it originated from humans and, of that tiny amount, 99 percent of which was generated through nuclear weapons testing in the ‘40s - ‘60s — not accidents like Chernobyl, Three-Mile Island or Fukushima. “The [health] effects are virtually negligible,” Fisher said. “This is true for, certainly, Three Mile Island where there was essentially no radioactivity released that ended up in the ocean.”
Understand that humanity has been dumping radiation — often literally — into our oceans since we first split the atom. From the early ‘40s to 1962, the United States government made a series of remote atolls, part of the Marshall Islands archipelago, practically glow in its pursuit of atomic weapons. The Soviets were notorious throughout the Cold War for dropping radioactive waste into the Arctic and Barents Seas — including more than a dozen reactor cores salvaged from decommissioned submarines and icebreakers. The Sellafield nuclear reprocessing plant in Cumbria, operated by British Nuclear Fuels, polluted the Irish Sea with radioactive waste for decades, while the La Hague power plant located along the Normandy coast has deposited similar wastes into the English Channel.
Incredibly, all of the radioactive material humans have plopped into our seas is literally a drop in the ocean compared to the amount of natural radiation found there. “The ocean is quite radioactive, much more so than rivers,” Dr. Henrietta Dulai, Associate Professor at the Department of Geology and Geophysics, UH Mānoa, said in 2019. “Sodium and chloride make it salty, but that is also caused by other major ions such as potassium. Potassium-40 makes the ocean very radioactive. There are 10,000 units of potassium for every unit of caesium in the ocean, even after Fukushima.”
Dr Fisher further explains that “more than 99 percent of the doses that marine organisms get from radioactive substances is from natural material, primarily a radioisotope called polonium-210.” This element is ubiquitous in the ocean, forming from the decay of uranium-238 found in bedrock, though polonium is an alpha emitter and therefore can potentially raise one’s risk of eventually developing cancer upon exposure.
The 250 million gallons that the Japanese government wants to disperse is a combination of water used to keep the damaged reactors and fuel ponds cool as well as ground and seawater that seeps into the site. TEPCO estimates that every day, approximately 1000 cubic meters of
groundwater flows into the area around the damaged reactors with another 400 cubic meters flowing into the facility buildings’ basements. This water becomes contaminated with oil pollutants as well as radioactive materials and therefore must be cleaned before being released back into the environment, through a process known as the Advanced Liquid Processing System (ALPS). After cesium and strontium concentrations in the contaminated water are reduced, the liquid is subjected to iron and carbonate pretreatment precipitation tanks before passing through a series of 16 absorption towers which leach out virtually all of the radioactive materials it contains, save for a bit of stubborn Tritium.
Tritium is “about as harmless as you can get in terms of a radioactive substance,” Fisher explained. It’s a naturally forming hydrogen ion created when cosmic rays collide with air molecules in the atmosphere. As such, tritium exists in trace amounts throughout the Earth’s groundwater aquifers. What’s wild is that tritium can bond with oxygen in exactly the same way regular hydrogen does to produce “tritiated” water. Though technically radioactive, this is different stuff than “heavy water” and is chemically identical to regular water. As such, there’s no way to filter titrated water out of a body of water without eliminating all of the water altogether. What’s more, tritium doesn’t exhibit any toxicity when concentrated in the body, half of it is excreted roughly every ten days, and while it does emit radiation, it’s a beta emitter making it just slightly less dangerous to the public’s health than its alpha-emitting cousin, polonium-210. Still, TEPCO isn’t taking any chances and will dilute the tritium to 1500 becquerels per liter — 1/40th of what Japanese environmental standards demand and 1/7th that required by the World Health Organization’s drinking water guidelines.
As of 2018, the Fukushima cleanup effort was producing around 170 cubic meters of ALPS-treated water every day and storing the material in its expanding archive of protective steel containers, which is expected to reach capacity by the summer of 2022. The Japanese government unfortunately cannot simply load these canisters onto a barge and head for deeper international waters away from offshore fisheries because that would be a violation of the London Convention. The government does also have the option to conduct a vapor release (essentially allowing the treated water to slowly evaporate away) but argues that the oceanic release is the more efficient disposal method. It has has also asserted (slide 2) that “even if the entire amount of the ALPS treated water stored in the tanks were to be disposed of in one year, the impact would be no more than 1/1,000 of the exposure impact of natural radiation (2.1 mSv/year) in Japan.”
So while the long-term environmental impacts of the Fukushima incident will not be fully realized for years or potentially decades to come, the initial results of the event have biologists cautiously optimistic. Dr. Fisher does not foresee major health risks for pescatartians (especially since Japan has engaged in a voluntary ban on seafood exports in recent years). “The biggest impact would be on the fishermen, on their livelihoods,” Fisher stated. “But I do not expect that there will be any public health impacts to people eating any of the seafood that they happen to harvest and sell.”
I do think a systematic monitoring effort in coastal waters is relatively inexpensive to do and would provide factual information rather than on fear or suppositions,” he continued. [We] “are going to need actual hard numbers about just how much radioactivity is building up in our seafood and how much radioactivity human beings get from eating that seafood, and what the impact of that radioactivity would be on our bodies and compare that to the radioactivity we're exposed to in our daily lives.”