What are the Negative Health Effects of Mercury?
Mercury in fish affects people in various ways. Even small amounts of exposure to mercury can cause serious health problems in humans and animals. There are different types of mercury and different ways you can be exposed to it in your environment.
Eating shellfish and fish is a source of mercury exposure, but this doesn’t mean that you should completely avoid fish altogether. Fish is an excellent source of nutrients.   
In the United States, government agencies suggest keeping blood mercury levels below 5.0 mcg per liter. 
One U.S. study of 89 people showed mercury levels ranged from 2.0-89.5 mcg per liter on average. 89% had levels above the maximum limit. The study reported higher fish intake was associated with higher mercury levels. 
Many studies show that people frequently consuming larger fish like perch and pike have higher levels of mercury.   Higher levels of mercury in humans and animals have been linked to brain issues, such as a decrease in fine motor skills, attention, memory, and dexterity. 
Health advocates are widely discussing the negative health consequences of heavy metals like mercury. Studies have associated heavy metal exposure with conditions like Parkinson’s, autism, depression, anxiety, and Alzheimer’s. More studies are necessary to confirm this association. 
Mercury exposure has also been tied to an increased risk of heart attacks, high blood pressure, and higher LDL or ‘bad’ cholesterol.    A study of 1,800 men showed those with the highest mercury levels were twice as likely to die from heart problems compared to men with lower levels. 
Most experts and advocates recommend moderating consumption of high-mercury fish and believe the nutritional benefits of fish likely outweigh the risks from mercury exposure. 
Some people may be more at risk than others, such as pregnant women or women who may become pregnant, breastfeeding mothers, and young children. Children, infants, and fetuses are more vulnerable to mercury toxicity, and mercury can also pass to a breastfeeding mother’s infant or a pregnant mother’s fetus. One study highlighted how children exposed to mercury in the womb have difficulty with language, memory, motor function, and attention.