The disposal of Fukushima’s contaminated water poses profound and potentially catastrophic risks to the environment and therefore seafood, according to scientists.
In August, 2023, the Tokyo Electric Power Company (TEPCO) started discharging radioactively contaminated water from the Fukushima Daiichi Nuclear Power Plant into the ocean. The treated water, processed by the Advanced Liquid Processing System (ALPS), is diluted and released into the Pacific Ocean through a 1-km-long tunnel. Tritium is the primary radioactive element in the ALPS treated water, with an annual discharge limit of 22 terabecquerels (TBq) for a projected 30 to 40 year period.
Supporters of the plan suggest minimal ecological impact from the treated water discharge, while opponents express concerns about potential long-term risks to neighboring regions.
According to the study, published in Environmental Science and Technology, Fukushima contaminated water contains 63 non-tritium radionuclides. Once incorporated into organisms, these radionuclides accumulate in different organs and humans can ingest them through seafood consumption.
Role of seafood trade
Scientists said because of the migratory behavior of some marine species and the international distribution of seafood, the migration speed of radionuclides carried by organisms may exceed that of ocean currents.
The researchers from Chinese institutions proposed the Fukushima Contaminated Water Risk Factor (FCWRF) for quantifying risks associated with radionuclides releases. It integrates the different areas of environmental transport, bioaccumulation, and seafood circulation.
After 1,000 days of discharge, certain countries and regions may face risk values hundreds or thousands of times higher than the benchmark because of bioaccumulation, migration and seafood circulation.
The study focused on the interaction between Caesium-137 and the Pacific bluefin tuna population. According to the discharge plan, the activity of Caesium-137 is set to be 0.31 times that of tritium. It was chosen instead of tritium because of its higher bioavailability.
Within 1,800 days after the discharge, an assessment was undertaken to evaluate the potential risks posed by Pacific seafood through international trade. Findings demonstrated the global spread of potential risks from the Fukushima contaminated water discharge, affecting regions such as Asia, Europe, and North America.
Regions with larger seafood import volumes, such as China, the United States, South Korea, Taiwan and Thailand face higher risks. China, Hong Kong, and Russia imposed import restrictions of fishery products from Japan following the discharge plan.
Underestimated risks
Scientists said results highlight underestimated risks to the environment and human health caused by the discharge when only diffusion dynamics are considered.
They made three recommendations including ensuring data transparency and providing public education on the risks as well as strengthening the risk and environmental impact assessment of the water discharge, and improving standards for radionuclides detection and monitoring frequency.
In cases where results meet high standards, policymakers should issue statements to mitigate public panic and protect the development of aquaculture and fishing industries, according to the report.
In March, the International Atomic Energy Agency (IAEA) task force said the discharge of treated water from the nuclear power station was proceeding in line with international safety standards.
The IAEA believes that discharges as planned would have a negligible radiological impact to people and the environment.
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