Mercury is a naturally occurring metal and a liquid chemical element at room temperature.
- It is one of the primary pollutants of concern in Indiana’s rivers and streams
- It cannot be artificially produced and it does not break down into other substances
- It conducts electricity and is especially useful in a variety of electronic devices and in industrial applications
- It is highly toxic to humans and wildlife and so must be handled and disposed of properly.
In humans, it can damage the liver, kidneys and brain. If ingested, mercury can affect the central nervous system. Mercury also accumulates over time in the bodies of animals, including humans, meaning that prolonged exposure to small amounts of mercury can potentially be as dangerous as exposure to a large amount at once.
Because mercury is a liquid at room temperature, it forms beads that can accumulate in the tiniest places. These mercury droplets can give off odorless mercury vapor. Breathing this vapor can be very dangerous depending on how much mercury is in the air and how long you breathe it. Small children and pregnant women are at the highest risk for health impacts from mercury, but everyone can be affected.
As a pollutant, it stays in the environment for a very long time. About two-thirds of the mercury found in the environment today is there because of human activity. Mercury is released as pollution when coal is burned in electric generating plants. It also comes from industrial processes and from improper disposal of household products that contain mercury. Because mercury is a liquid and because it easily evaporates into the air, it can enter our environment very easily. It is believed that much of the mercury in rivers and streams is actually deposited there from the air. Once mercury is in the environment, it can be very difficult to clean up. It spreads easily and stays around for a long time. A very small amount of mercury can cause a big problem. Just 3 grams of mercury can contaminate a 60 acre lake. A typical mercury thermometer alone contains ½ to 2 grams of mercury. Three grams equals about 1/25 of a teaspoon.
What are the sources of mercury?
- Thermometers with silver colored liquid inside
- Thermostats (non-electric)
- Clothes irons with an automatic shut-off function
- Fluorescent light bulbs and mercury vapor lamps
- Some latex paint manufactured before 1990 (mercury was used to inhibit the growth of mold)
- Batteries (Mercuric oxide and some alkaline batteries)
- Gauges such as barometers and older blood pressure meters
- Electrical switches on appliances such as space heaters, freezers, and sump pumps
- Laboratory chemicals
- Antibacterial products containing thimerosal or merbromin
- Scientific apparatus
How can I prevent mercury pollution?
- Learn about common products that contain mercury
- Make a list of the products in your home that contain mercury using the Mercury Information Flyer
- Avoid buying products that contain mercury except for fluorescent light bulbs. Fluorescent bulbs use less electricity than incandescent bulbs.
- Keep mercury-containing items out of the trash (including fluorescent light bulbs). Use appropriate disposal methods or recycle mercury-containing products.
- Make an effort to reduce reliance on coal burning by conserving electricity whenever possible.
- Never break open items that may contain mercury
- Never burn mercury
- For further information about human exposure to mercury, please call the Poison Center at (800) 222-1222.
- For information about disposal of mercury-containing items in Allen County, Indiana, contact the Allen County Department of Environmental Management at 260-449-7265.
- More resources are available from the Indiana Department of Environmental Management
Special Information for Dentists
Amalgam materials used in the past for filling dental cavities often contained mercury. Although mercury is no longer used by dentists, dental offices are required to have special equipment including amalgam separators that trap mercury and allow it to be properly handled.
New dental offices are required to submit a report to City Utilities to let us know that you are meeting the requirements of the federal rules. Also, dental offices that are bought or sold must submit a report at the time of sale. In 2020, all dental offices will be required to submit a report.
This form may be downloaded, filled in, then printed and mailed to the Water Pollution Control Plant