Mercury is a toxic heavy metal found in air, water and soil. It can be dangerous to humans even in small amounts. The main source of exposure to mercury is through the consumption of fish. Fish can accumulate mercury when they reside in contaminated water. Eating fish contaminated with mercury can cause serious health effects in people, even at low exposure levels......READ THE FULL ARTICLE>>>
Therefore, it is important to be aware of which types of fish have the highest mercury content and take steps to reduce the risk of mercury poisoning. This article provides an overview of mercury toxicity, sources of mercury in fish and the types of fish that should be avoided because of their mercury content and its potential negative health effects.
What is Mercury and Its Sources?
According ro CDC, Mercury (Hg) is a heavy metal found throughout the environment. It can be found in air, water and soil and can be released both naturally and through human activities.
Natural sources of mercury include volcanic eruptions, weathering of rocks and burning of vegetation, while human sources include coal-burning power plants, incineration of municipal waste and mining operations.
Once in the environment, mercury cycles and is moved around. It can accumulate in living organisms and in aquatic ecosystems. In water, mercury includes several forms, such as organic mercury, elemental mercury, and inorganic mercury compounds. Fish and shellfish are the major consumers of the organic form of mercury, methylmercury, which is generated through a chemical process from inorganic mercury.
Effects of Mercury Poisoning
Exposure to mercury can cause a variety of health effects. In humans, effects of mercury poisoning can include reduced IQ, motor deficiencies, reduced hearing, impaired vision, nerve damage and kidney damage. Exposure to mercury in pregnant women can result in miscarriage, high blood pressure, fetal exposure and impaired neurological development in the fetus.
In large amounts, elemental mercury is most toxic, followed by methylmercury and then inorganic mercury compounds. Generally, people are exposed to mercury mainly through the consumption of contaminated fish, which is the form of methylmercury. Therefore, it is important to know which fish should be avoided and which ones have low mercury content.
Sources of Mercury in Fish
Fish and shellfish are the main dietary sources of mercury due to their ability to absorb methylmercury from the water and accumulate it in their tissues.
The amount of mercury present in a particular species of fish depends on its age, size, and variety of food consumed. Generally, larger, longer-lived predatory and bottom-dwelling fish have a higher level of mercury in them.
Identifying Types of Fish with High Mercury Content
When choosing which types of fish to eat, it is important to check what types of fish have higher levels of mercury and which do not. Generally, larger, longer-lived predatory and bottom-dwelling fish such as shark, swordfish, king mackerel, tilefish, tuna and marlin have the highest levels of mercury.
These fishes should be avoided as much as possible. Other types of fish such as cod, salmon, haddock, pollock, sardines and tilapia have low mercury content and can be safely consumed.
In addition, shellfish such as clams, mollusks, shrimp, squid, and oysters typically have low levels of mercury and can be safely consumed.
Nutritionists recommend eating more seafood as a part of a balanced diet. Eating seafood low in mercury can provide important essential fatty acids, vitamins, minerals and protein while avoiding the dangers of mercury toxicity.
Mercury is a toxic heavy metal found in air, water and soil and can accumulate in living organisms, including fish. Eating contaminated fish can increase the risk of mercury poisoning and its associated health effects. Therefore, it is important to be aware of which types of fish have the highest mercury content and to take steps to avoid them.
Generally, larger, longer-lived predatory and bottom-dwelling fish such as shark, swordfish, king mackerel, tilefish, tuna and marlin should be avoided, while cod, salmon, haddock, pollock, sardines and tilapia have low mercury content and can be safely consumed. Eating seafood low in mercury can provide important essential fatty acids while avoiding the dangers of mercury toxicity.
