Mercury in Water

Mercury in Water

Question #1: What is Mercury?

In it's metallic state, mercury is a shiny, silvery liquid metal at room temperature. It is odorless and evaporates into the air slowly. As a metal it is used in electric switches, thermometers and fluorescent lights. It used to be used in filling cavities.

Mercury can combine with other elements to form two kinds of compounds:

• It can form inorganic compounds which are used in batteries, paper manufacturing, and chemical industry. Mercury in water is usually found in this inorganic form.
• It can form organic compounds. This is its most harmful form but mercury in water is not usually found in this form. Mercury as an organic compound is found in large fish such as bass, shark, sword fish and tuna. For example, it is spewed into the atmosphere from factories along Lake Michigan. It can be carried fifty miles by air and come down into the lake along with rain or snow. It then lodges in the muscle of large fish and then is eaten by humans.

Question #2: How does mercury come to pollute our drinking water?

Large amounts of mercury are released naturally from the earth's crust. Other sources include traces of mercury in oil and coal that are released through burning. Metal smelting and cement manufacture pollute the atmosphere with mercury. Another source is municipal landfill as well as sewage. The incineration of materials containing mercury, such a batteries, will spew mercury into the air.

Wind and rain carry mercury even great distances from its source and deposit it in lakes, rivers and reservoirs. Run off from rain and land fill seep into the ground to become a part of underground water.

Question #3: How can mercury in water affect my health?

The type and severity of the health effects of mercury depend on the kind of mercury you are exposed to and the quantity that has built up in your body. Inorganic mercury, the kind usually found in drinking water, doesn't usually have much affect on adults. But young children are more vulnerable. High levels of exposure can affect the nervous system causing symptoms such as irritability, nervousness, changes in vision or hearing and difficulties with memory. We don't yet know the impact, if any, of low levels of exposure.

Organic mercury, the kind not usually found in drinking water, has more serious effects. At high levels it can damage the nervous system and the kidneys. It is particularly harmful to young children and can interfere with brain development.

Question #4: How big a problem is mercury in my drinking water?

It is estimated that 68,000 pounds of mercury were released into the waters and land of the U.S. from 1987 to 1993. A lot of this has come from chemical and related industries. The top six states to release mercury are Tennessee, Louisiana, Delaware, Ohio, Alabama, and West Virginia. Hence, it is in those states that mercury in drinking water is most likely to be found.

Question #5: How can I tell if mercury is in my drinking water?

If you get your tap water from a public water system, they are required by law to send you annually a Consumer Confidence Report (CCR). You can find information on contaminants that were above the Maximum Contaminant Level (MCL) on the Environmental Protection Association (EPA)website. Look to see if there is mercury in your water and how much. They cite the "Level Found" and the "MCL" (Maximum Contaminant Level). For mercury, the standard set by the EPA is .002 milligrams per liter. Any water which has more than this amount of mercury is not safe. The water company is required to state that mercury is over the MCL limit and what they are doing to correct this.

If you get your tap water from a private well, it is recommended that you have it tested for mercury and other pollutants that may make it unsafe to drink as is. You can order a water testing kit and test it yourself or hire a water testing laboratory in your area to do it for you.

Question #6: How would I go about removing mercury from my drinking water?

There are three kinds of filters that can remove mercury in water from your tap water: Distillation, Reverse Osmosis, and Filtration (granular or carbon block). However, you need to check the individual filter that you are considering to not only see if they claim to reduce mercury, but if this has been certified by the NSF International as a filter that does indeed effectively reduce mercury.

For more information about mercury and other toxic contaminants, go to "Mercury in Water".

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