Tag Archive: Great Lakes


It’s nothing new; everyone knows that the Great Lakes are polluted. However, researchers have recently found pharmaceutical byproducts in Lake Michigan and Lake Erie which raise new concerns about the potential health risk for more than 40 million people who rely on the Great Lakes for drinking water.

The drugs are only a small part of the contaminants that make up the chemical soup stretching from Minnesota to New York. 

A new study by Alliance for the Great Lakes looks at existing data on chemicals and chemical byproducts in the lakes and the impact it may have on the Great Lakes.  “Exposure to some of these chemicals…is cause for consternation for people and concern over fish and wildlife impacts,” writes lead author Dr. Rebecca Klaper, Shaw Associate Professor at the Great Lakes WATER Institute in Milwaukee.

What’s in the chemical soup?

The study shows that there several emerging contaminants in the Great Lakes today including flame retardants, modern pesticides, pharmaceuticals, the antibacterial and antifungal agent Triclosan and the insect repellant DEET. The now famous bisphenol A (BPA)  used in a  large variety of plastics including baby bottles and food packaging, was found in more than half the water samples analyzed to date.

The conclusion

 There’s too little data  and not enough understanding about the emerging contaminants to know how they’ll affect the health of the Great Lakes organisms and the people who live around the lakes. Due to the flawed U.S. system for managing chemicals, exposure to some of these manmade and naturally occurring chemicals, in  water, land and air, is unavoidable. 

The Alliance is calling for a national comprehensive plan to address gaps in research regarding emerging contaminants’ potential harm to public health and the environment and to identify which chemicals may be the most damaging.

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Mercury and the Great Lakes

 

Where are the Great Lakes?

The five lakes – Huron, Michigan, Erie, Ontario and Superior – cover 94,000 square miles and make up 20% of the world’s freshwater. Lake Michigan is the only lake located entirely in the United States; the other lakes share an international border between the U.S. and Canada. The Great Lakes basin is the most ecologically diverse freshwater system of its kind.

What is Mercury?

Mercury is a naturally occurring element that is found in cinnabar, volcanic eruptions, forest fires and many rocks including coal. Human activities, such as coal-fired power plants and manufacturing, have drastically increased the amount of mercury in the environment. Mercury in the air, from various sources, can settle in the water or on the land where it’s washed into the Great Lakes or tributaries.

Once in the water, microorganisms take mercury into their system and convert it into methylmercury, a toxic form of mercury. As methylmercury moves up the food chain, from shellfish to frog to fish to human, it accumulates in the tissues and becomes more toxic. Fortunately, the levels of methylmercury in fish and shellfish depend on how long they live, where they are in the food chain and what they eat.

Humans become exposed to methylmercury when they eat shellfish or fish from the Great Lakes. Mercury poisoning has resulted in development defects and neurological problems in fetuses and infants including cerebral palsy, and nervous system problems in adults. Exposure to mercury can also lead to nausea, loss of color vision, kidney damage, tremors, paralysis and even death.

 

Joint efforts to reduce Mercury

Since 1972 the U.S. and Canada have entered into joint agreements designed to reduce or rid the Great Lakes of persistent toxic substances including mercury. One of the most notable achievements is the Clean Water Act which is regulated by the Environmental Protection Agency (EPA) and has developed water quality criteria for human health and aquatic life in the Great Lakes states. The EPA has also issued water quality criteria for methyl mercury that is used by states to determine acceptable levels of methyl mercury in fish and fish tissues. Additionally, the U.S. has developed two pretreatment standards for toxic substance release from industries, categorical – which are industry specific and applied on a national level, and local limits – which apply to all industries in the general area.

The sale of mercury thermometers has been banned in many states and batteries have also been added to the list to reduce the release of mercury. The most recent and perhaps most important mercury ruling in 2004 seeks to permanently cap and reduce mercury emissions from coal-fired power plants.

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