The recent decision to release treated Fukushima nuclear wastewater into the sea, beginning on August 24, has once again sparked concerns regarding the safety of seafood consumption. With this development, there is a great need for ongoing monitoring to ensure the removal of radioactive elements like strontium-90 and cesium-137, both of which carry carcinogenic risks, during the treatment process. The public must exercise caution when consuming deep-sea large fish due to the risk of methylmercury poisoning, which can damage the central nervous system and lacks a known antidote.
Japanese authorities have announced that the wastewater, treated with the Advanced Liquid Processing System (ALPS), will be discharged into the sea with all radioactive substances removed, except for tritium, which remains at concentrations below 1,500 becquerels per liter. The International Atomic Energy Agency (IAEA) has endorsed Japan’s plan, asserting its compliance with international standards. Nevertheless, concerns persist among the public regarding potentially harmful substances in the discharged wastewater.
Tritium, in theory, poses minimal risk when present at concentrations below 1,500 becquerels per liter, as it is commonly found in the environment and does not significantly penetrate the human body. However, concerns revolve around the possible presence of strontium-90 and cesium-137, given their longer half-lives of 29 and 30 years, respectively, and the fact that only 12 years have elapsed since the nuclear disaster. Continuous monitoring is essential to determine whether these pollutants exceed established safety standards following the wastewater discharge.
The consequences of strontium-90 and cesium-137 entering the human body may be severe. Cesium, chemically similar to potassium, has a propensity to accumulate in muscles, soft tissues, and organs, elevating the risk of various cancers. Strontium, structurally akin to calcium, readily accumulates in bones, increasing the risk of bone cancer and leukemia.
Aside from nuclear radiation, you should be cautious about heavy metal contamination, particularly methylmercury, when consuming seafood, especially deep-sea large fish like tuna, shark, and swordfish. These long-lived fish accumulate substantial amounts of methylmercury over their years in the ocean. Methylmercury can impair the central nervous system and pose risks to pregnant women and infants, potentially diminishing a child’s IQ by up to 1.5 points, as observed in a U.S. study.
Notably, mercury is categorized into three forms: elemental, organic, and inorganic. While chelating agents can help remove elemental and inorganic mercury from the body, there is currently no antidote for methylmercury, which is organic in nature. Therefore, it is imperative to avoid excessive consumption of methylmercury-contaminated seafood.
To balance nutritional benefits from fish with the avoidance of fish toxins, Dr. Yen suggests the following precautions:
- Prioritize Small Fish: Opt for smaller fish, approximately the size of your hand, as they have shorter lifespans and lower mercury content.
- Avoid Fish Heads, Skin, and Organs: These parts of the fish tend to harbor toxins, including mercury and other heavy metals, environmental hormones, and polychlorinated biphenyls (PCBs), making them unsuitable for consumption.
- Limit Deep-Sea Large Fish Consumption: For adults weighing around 110 pounds (50 kilograms), it’s advisable to consume a maximum of 80 grams of deep-sea large fish per week, equivalent to half the size of your hand or three to four slices of sashimi.
- Caution for Children and Pregnant Women: Due to the potential impact of methylmercury on intellectual development, children under six and pregnant women should avoid deep-sea large fish. This aligns with the U.S. Food and Drug Administration’s (FDA) recommendations.
- Stay Hydrated: Drinking plenty of water can aid in the detoxification process, as most heavy metals are water-soluble and can be excreted through urine.