Even moderate mercury consumption has serious consequences, namely for women and children. To minimize mercury ingestion, it’s necessary to understand how mercury enters the environment and our bodies.
The major contributors to environmental mercury contamination are coal-burning power plants. Heavy metals, including mercury, are spewed into the air when coal is burned for fuel. Once emitted, these toxins enter our waterways and are introduced into the food chain. Bacteria in lakes and rivers digest the mercury, creating a compound called methyl mercury. This mercury-laden bacteria move up the food chain and accumulates in larger fish, like tuna and swordfish, which are then consumed by humans. Because mercury accumulates in the fish and bacteria at the very bottom of the food chain, the larger fish that are popularly consumed can have concentrations of the chemical thousands of times greater than their surroundings. Methyl mercury is especially easily absorbed by humans, putting anyone who consumes aquatic animals at risk. It will naturally be expelled from the human body, but it may take 6 months to a year for mercury levels to significantly decrease.
Pregnant women and young children are most affected by mercury exposure. As it accumulates in women’s bodies, it reduces fertility and raises the probability of developmental disabilities in children exposed to even moderate levels in utero. Children exposed to air-borne pollutants like mercury have a much higher incidence of respiratory illnesses, like asthma and acute bronchitis. While no amount of mercury is beneficial, it’s important to know what kinds of fish have the highest levels and consumption of high-risk fish should be limited.
Michigan is surrounded by the Great Lakes, some of the nation’s largest sources of fresh water, which are endangered by the several coal-burning power plants located on Michigan’s coastline. One of the top mercury-polluting coal plants located within 200 miles (the Monroe Power Plant in Monroe) of Grand Rapids. Fortunately, the EPA has recently passed new emission limits for coal-burning power plants. On December 21, 2011, the Environmental Protection Agency issued new Mercury and Air Toxics Standards, which will require power plants not already meeting EPA standards to do so within the next 3 years. Though no level of mercury emissions is “safe”, this will go a long way to reduce mercury levels in our water system. The EPA claims that it will reduce instances of childhood asthma, acute bronchitis, heart attacks and other serious illnesses. With a greater understanding of how people are exposed to mercury and the implementation of the new EPA standards, we can reduce the amount of respiratory illnesses and developmental disabilities for future generations.