Mercury Information

Mercury drops

What is Mercury?

The Basics:
The shimmering liquid metal mercury is one of the basic natural elements that make up the Earth's composition. Mercury is known as a "heavy metal" because it is very dense. A cup of mercury, for example, is more than fourteen-times heavier than a cup of water.
Mercury in Our Environment...
Low levels of mercury can be found throughout the environment--in rocks, plants, animals, water and the air. Mercury becomes airborne when rocks erode, volcanoes erupt and soil decomposes. It then circulates in the atmosphere and is redistributed throughout the environment.Mercury factoid
Mercury is also released into the environment (typically airborne) when coal, oil or natural gas is burned or mercury-containing garbage is incinerated. Once in the air, mercury can fall to the ground with rain and snow, landing on the soil or in various water bodies, causing contamination. Lakes and rivers can also become contaminated when there is a direct discharge of mercury-laden industrial waste or municipal sewage. Once present in these water bodies, mercury accumulates in fish and may ultimately reach the dinner table.
Mercury's Effect on Humans...
Mercury has been a part of human culture throughout history.  In more recent times, mercury was used for preparing felt for hats, controlling mildew in paints, killing weeds as a component of herbicides, as well as various medical uses (using mercury in these ways is no longer common).  Today, we recognize that mercury is a neurotoxin. Exposure to mercury can deteriorate the nervous system, impairing hearing, vision, speech and even a person's gait. It can also cause involuntary muscle movement and make chewing and swallowing more difficult. High levels of exposure can lead to serious illness or even death. Locally, the majority of exposure to mercury is the result of eating fish containing mercury or when a product containing mercury is broken and the mercury is exposed to air or directly contacted. Knowing what products may have mercury as well as the proper disposal can help ensure that humans and the environment are protected.
Mercury Containing Items:
Fish - nearly all fish and shellfish contain traces of mercury depending on where the fish was caught and the type. Be sure to check for fish advisories before consuming.

Thermometers - mercury is used in fever, basal, weather, and candy/deep fry thermometers since mercury expands and contracts evenly with changes in temperature.

Lights - mercury is used in fluorescent lights, neon lights, outdoor security and street lighting, and headlights. Fluorescent lights, however, are very energy and cost efficient so they should be used, but recycled.

Dental Amalgamalso known as "silver filling", it is made of two nearly equal parts: liquid mercury and a powder containing silver, tin, copper, zinc and other metals.

Button Batteries - including in watches, hearing aids, toys and other devices requiring small batteries, contain small amounts of mercury.

Switches & Relays - mercury has been used as an electrical conductor in a variety of switches. When the device is moved, the switch tilts and mercury makes the electrical contact.  Many manufacturers have removed these switches but they still may be found especially in older items. Examples include: non-digital thermostats, chest freezer, automobile hood lights, irons/space Heaters, washing machine, laptop computer, lawn mowers.
For more information about sources of mercury please check out the EPA website at: