According to the results of the 3rd National Environmental Health Survey released by the Ministry of Environment in December last year (2018), the mercury concentration in Korean middle and high school students was 1.37 ㎍ / L and the adult was 2.75 ㎍ / L. Blood mercury levels in adults are twice as high as in adolescents (Source: Ministry of Environment, 2018).
The Ministry of Environment said that the levels of mercury in both middle and high school students were less than the recommended value (HBM-1) suggested by the German Human Monitoring Commission, taking into account toxicological and epidemiological factors. However, blood mercury levels in Korean adults are two to three times higher than those in the United States, Canada and Germany (Source: Korea Centers for Disease Control and Prevention, 2018).
As climate change progresses due to global warming, mercury build up in our bodies can increase. A joint team of researchers from the United States, India, and Canada, including Harvard University, recently published a study showing that climate change and overfishing can boost human mercury intake (Schartup et al., 2019).
The team analyzed and analyzed the ecosystem data of the Gulf of Maine in the eastern United States, methyl mercury accumulated in seawater, sediments, and fish for over 30 years from the 1970s to 2000s. A model was developed to evaluate how changes and overfishing affect the buildup of metallic mercury in vivo. Observational data and models are used to calculate how changes in the environment, such as seawater temperature rises and overfishing due to climate change, can affect fish's changes in methylmercury.
● Water temperature 1 degrees Celsius rise… Cod Mercury Concentration 32% ↑ Dome Shark Mercury Concentration 70% ↑
As a result of comprehensive analysis of the observational data, the methylmercury concentration of fish increased significantly as the seawater temperature increased. Mercury emissions declined between 2012 and 2017, while the concentration of methylmercury in bluefin tuna in Maine Bay increased by more than 3.5% annually. If the seawater gets hot in the future, it means that the mercury concentration of fish is likely to increase rapidly. Indeed, the Maine Sea is one of the fastest rising water temperatures in the world as climate change progresses due to global warming.
In particular, when the temperature of seawater rises by 1 ℃ compared to 2000, the methylmercury concentration of 15kg cod is 32% higher and the methylmercury concentration of 5kg Spiny Dogfish is 70% higher. The researchers found that the warmer the ocean waters are due to climate change due to global warming, the more energy the fish need to swim, and the more food they eat to get the necessary energy, eventually accumulating more mercury in the body. Analyzed. Naturally, slower swimmers swim faster than smaller ones, and larger fish require more energy and eat more food, resulting in more mercury in the body.
● overfishing and mercury concentration
Changes in prey due to overfishing also have a significant effect on the concentration of methylmercury in fish. According to the survey, the concentration of methyl mercury in cod in the 1970s was 6-20% lower than that of cod in the 2000s. On the other hand, the methylmercury concentration of domed sharks was 33-66% higher in the 1970s than in the 2000s.
The team found the cause of the large changes in mercury concentrations in both fish over 30 years from the change in food. Indeed, in 1970, overfishing herring declined sharply, while cod consumed small fish under herring in the food chain, while domed sharks fed cephalopods, such as squids with high levels of methylmercury. Will. As the food of the cod and the domed shark that were feeding the same herring changed, the mercury concentration of the domed shark increased and the mercury concentration of the cod decreased.
However, as overfishing disappeared in the 2000s, herds re-grown, and cods that ate small fish ate higher levels of mercury as they ate above herrings in the food chain. The concentration of methyl mercury in the building is lowered. Eventually, the fish's methylmercury concentration changed significantly as the food chain changed depending on overfishing.
The team used the model to calculate how the mercury concentration in fish changes, especially with changes in sea temperature, changes in mercury emissions, and when food is lost to overfishing.
The results of each scenario show that if the water temperature rises by 1 ° C and the mercury emission decreases by 20%, the mercury concentration in cod increases by 10% and the mercury concentration in domed sharks by 20%. In addition, when the temperature rises by 1 ° C and herring disappears by overfishing, the concentration of mercury in cods decreases by 10%, while the concentration of mercury in domed sharks increases by 70%. Of course, a 20% reduction in mercury emissions at a constant seawater temperature results in a 20% reduction in fish water concentration (see figure below).
About 3 billion of the world's population is known to get a certain amount of nutrition from seafood. In particular, Korea is relatively exposed to mercury due to its food-loving habits.
Mercury is also emitted in nature, but a significant amount comes from human activities such as coal burning, waste incineration and automobile smoke. Mercury is used in various ways around our lives, including fluorescent lamps, batteries, and pesticides. Most of the mercury released once accumulates in the ocean, and the mercury in the ocean is converted to methylmercury by microorganisms.
When mercury enters the living body, it is accumulated without being discharged. Through the food chain, mercury is concentrated in the predators such as cod, bluefin tuna, and swordfish. In particular, the accumulation of mercury in the body above the threshold can cause fatal damage to the nervous system. A typical disease is Minamata disease, a neurological syndrome manifested by mercury poisoning.
The Minamata Convention, an international agreement to reduce mercury emissions and eventually eliminate them, came into force on August 16, 2017, two years ago. As of August 23, 2019, 128 countries around the world have signed the Convention and 112 have ratified it. Korea signed the agreement on September 24, 2014, but has not ratified it yet. Climate change and overfishing are amplifying the mercury intake of mankind, which is also pressing Korea's ratification of the Minamata Convention.
<Reference>
* Ministry of Environment, 3rd National Environmental Health Basic Survey, Results Announced (2018)
* Centers for Disease Control, Environment and Health (2018)
* Amina t. Schartup, Colin P. thackray, Asif Qureshi, Clifton Dassuncao, Kyle Gillespie, Alex Hanke & elsie M. Sunderland, Climate change and overfishing increase neurotoxicant in marine predators, Nature, 2019
https://doi.org/10.1038/s41586-019-1468-9
[Report File] Climate Change, Mercury Intake Increases The reason is?
2019-08-22T13:08:51.181Z
According to the results of the 3rd National Environmental Health Survey released last December by the Ministry of Environment, the mercury concentration in Korean middle and high school students was 1.37㎍ / L, and the adult mercury concentration was 2.
Source: sbskr