Frequently Asked Questions

General Information

Why is reducing mercury pollution important?

Mercury is toxic to both humans and aquatic life (e.g., fish and shellfish), if ingested. Mercury exposure at high levels can result in adverse health effects that harm the brain, heart, kidneys, lungs and immune system of people of all ages. Unborn babies and young children are especially vulnerable, as exposure to high levels of mercury can damage their developing nervous systems and thereby affect their ability to think and learn.

Be Mercury Free seeks to educate the public about the hazards associated with mercury, the common sources of mercury in homes or businesses, and the best ways to prevent mercury from ending up in our waterways.

How does mercury end up in the environment and our waterways?

There are many ways mercury can end up polluting the environment. Because mercury can be a solid, liquid or vapor, preventing mercury contamination is difficult once it is released. Mercury can escape to the environment when it is dumped down the drain or when items containing mercury (see examples below) are broken or thrown away. Whether thrown in garbage cans or burned in incinerators, this improperly disposed mercury will eventually enter the atmosphere. The airborne mercury is then deposited to our lakes and streams when it rains, where it is converted by naturally occurring bacteria into methylmercury, a more toxic organic form of mercury that contaminates our water and our fish.

What is the best way to keep mercury out of the environment?

Pollution prevention is the best way to protect our health and the environment from mercury contamination. This means tackling the problem at the source so less mercury pollution is created.

One way you can help prevent mercury pollution is to safely dispose of mercury-containing items at a certified Household Hazardous Waste Facility (click here for a list of local facilities near you). You should also replace older mercury-containing products or equipment in your home with safer alternatives, whenever possible. Finally, know what to do to safely clean up a mercury spill in your home.

Where do we find mercury in our daily lives?

Mercury has properties that have made it useful in many different consumer and commercial products and industrial sectors. Sources of mercury include:

  • Fluorescent light bulbs
  • Button cell batteries
  • Older mercury thermometers and thermostats
  • Dental amalgam waste from silver fillings
  • Some electrical switches and relays
  • Some older laboratory equipment and chemicals used in medical facilities, schools and universities.

Mercury from all of these items can end up in our watershed if disposed of improperly.

One of the more common mercury-containing items found in our households today is compact fluorescent light bulbs (CFLs). CFLs and other fluorescent bulbs often break when thrown into the trash or when they end up in a landfill or incinerator, releasing mercury into the environment. Therefore, it is especially important to dispose of these items at local facilities for handling household hazardous wastes.

While the use of mercury has been reduced, you should be aware that some older items in your home or office—and even some new products available for purchase—may contain mercury.

Learn more about how to safeguard your home from mercury.

How do we know if fish are safe to eat?

For those who catch their own fish, the State of California regularly posts fish advisories and “safe eating guidelines” for specific water bodies. The U.S. Food and Drug Administration and the U.S. Environmental Protection Agency also offer advice to help you choose the safest commercially available fish to eat. Learn more about fish eating guidelines here.

Have more questions?

Contact the Be Mercury Free Program at (916) 875-6644 or

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