People fond of eating sushi are often worried about mercury in sushi as it is common to find mercury in fish. Although an average person who consumes a moderate amount of seafood containing mercury is not prone to serious health problems, this topic has been a very concerning issue.
It is stated in many reports that seafood has always contained mercury in the form of methyl mercury at very low levels of and do not pose a threat. Japan has consumed a lot of seafood (especially tuna, which has the highest mercury content of all sea foods) for hundreds of years and there are no data for health issues due to eating too much seafood
A person with a healthy liver and a pair kidneys that function properly can completely expel the low levels of methyl mercury contained in seafood. It takes about 70 days to detox half the amount of methyl mercury in the body. For the cautious people, American research papers claim that 6 oz of tuna per week is a very safe figure. However it is highly recommended for pregnant women to refrain from seafood. Although it is not a threat to the mother, the undeveloped fetus should be kept away from any trace of mercury.
Mercury naturally exists in low concentrations in the deep sea waters. Microorganisms that dwell in this area contain mercury,which are then transferred to their predators, the plankton. Small fishes feed on the plankton, which are then preyed by the bigger ones. The higher the fish in the food chain, the higher the mercury content becomes. The fishes that are highest in mercury are the tuna family, swordfish, and shark. It is also known that deep sea water fishes, such as Chilean sea bass, have higher mercury content.
In the mid 1950’s a disease named after Minamata City in Japan (located in southern Japan), where roughly 2500 cases of severe neurological damage in patients were reported due to industrial pollution. High amounts of industrial mercury waste were dumped in the Minamata bay and led to contamination of the fish that the local people consumed. The Minamata disease should not be confused as a disease resulting from consuming seafood in general. It was a result of poor environmental regulations, and not a natural cause. Present regulations are stricter than ever, and Minamata disease is not a concern any longer.
It is also important to know where the fish you regularly consume is caught. Some areas still have poor environmental regulations, and mercury may not only be the issue of concern.