Mercury FAQ’s

What is Mercury?

Mercury, also known as quicksilver, is an element that does not break down.  It occurs naturally and is found in very small amounts in oceans, rocks, and soil.  It becomes airborne when rocks break down, volcanoes erupt, and soil decomposes.  It then circulates and is redistributed throughout the environment.

Mercury can become airborne when coal, oil, wood, or natural gas are burned as fuel or when mercury containing garbage is incinerated.  Once in the air, mercury can fall to the ground with rain and snow, landing on soil or in bodies of water, causing contamination.

Lakes and rivers are also contaminated when there is a direct discharge of mercury-laden industrial and municipal waste into these water bodies.  Once present, mercury accumulates in the tissue of fish and other organisms and may ultimately reach your dinner table.

Although mercury is a very useful element with many unique properties and applications, it poses a very real health risk.  We can minimize this risk by reducing our use of mercury-containing products and disposing of mercury-containing waste.

How Does Mercury Effect Wildlife?

Eagles, osprey, loons, turtles, mink, otters, and other fish-eating creatures are at risk from eating mercury contaminated fish.  Mercury in their diets can cause early death, weight loss, and problems with their ability to reproduce.  Unfortunately, wildlife cannot read fish advisories or change their eating habits to avoid mercury contamination.

How Does Mercury Get Into Fish?

Once in a lake or river, mercury is converted to methylmercury by bacteria and other processes.  Fish absorb methylmercury from their food and from the water as it passes over their gills.  Mercury is tightly bound to proteins in all fish tissue, including muscle.  There is no method of cooking or cleaning fish that will reduce the amount of mercury in a meal.  Nationwide, mercury is represented in more fish consumption advisories than any other chemical.

Methylmercury accumulates as you move up the food chain:

1. Methylmercury in the water and sediment is taken up by tiny animals and plants known as plankton.
2. Minnows and juvenile fish eat large quantities of plankton over time
3. Large predatory fish consume smaller fish, accumulating methlymercury in their tissues.   The older and larger the fish, the greater the potential for high mercury levels in their bodies.
4. Fish are caught and eaten by humans and animals, causing methylmercury to accumulate in their tissues.

Pennsylvania has not issued any fish consumption advisories for Lake Erie or Presque Isle Bay due to mercury.  To stay updated on advisory listings, water sampled, and sampling methods contact the Pennsylvania Department of Environmental Protection (DEP) at 717-787-9637 or via the DEP web site at http://www.dep.state.pa.us/dep/deputate/watermgt/WC/subjects/fishadvisory.htm .  For Ohio advisory listings, contact the Ohio Department of Health at 614-644-6447 or via the world wide web at http://www.odh.state.oh.us

(info compiled from PA DEP website)