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Mercury levels in CFL bulbs safer than the alternative

February 9, 2010

You may have heard that the energy efficient compact fluorescent light (CFL) bulbs contain mercury and may be unsafe. While it’s true that they do contain small amounts of mercury, the mercury contained in that bulb is actually safer than the mercury released with the use of incandescent bulbs.

MU environmental science professor, Jan Weaver says, “It’s about the same amount of mercury used for both, but it is contained in the CFL bulbs. That makes a big difference in my mind.”

Even though incandescent bulbs do not contain any of the poisonous element, coal does. The coal, which is burned to make most of our electricity, has mercury in it. In order to burn an incandescent bulb for the lifetime of a CFL bulb, around 5.8 milligrams of mercury is released into the atmosphere, according to Weaver’s research.

Some power plants, such as MU’s, have mercury scrubbers in the smokestacks that remove 90 percent of the mercury from the plant’s emissions. However, 70 percent of the nation’s coal-fired plants do not have the scrubbers and the mercury continues to be released into the air.

The mercury enters the atmosphere where it is absorbed by clouds and rains down into our lakes and ponds. Small fish eat the particles in the water, and bigger fish eat those fish, continuing on in a process of bioaccumulation until one of those big fishes ends up on someone’s dinner table with a significant amount of mercury in it.

Weaver says that most people can handle it, but it can harm developing brain cells. “If a pregnant woman eats those fish it can cause mental retardation and other birth defects in their child.”

CFL bulbs contain 4 to 5 milligrams and the energy used to power them burns about 1.2 milligrams, making the amount of overall mercury about even.

However, as Weaver says, it’s better to have the mercury contained. By taking the old CFL bulbs to the proper waste management services, that mercury can be disposed of in a way that prevents it from entering the ecosystem. Contact your local waste management services to find out how you can safely dispose of the energy efficient bulbs. Columbia residents can find more info on the city’s website.

5 Comments leave one →
  1. February 19, 2010 4:59 pm

    If you don’t like coal-firing plants’ Hg emissions, better do something against these, don’t blame a product like the incandescent light bulb! Not one power plant will get switched off because people buy or are forced to buy CFLs. Not one ice-bear more will survive if you frantically throw out your incandescents! That’s just wishful thinking and make-believe installed by the lighting industry and energy producers that are reluctant to do something really significant about environmental issues a.k.a. climate. If you don’t like emissions, then tax emissions! If you think people are using too much electricity, then tax electricity! Economics 101, anyone?

    And how ridiculous it is to be claiming that mercury were safe inside a glass product that is routinely handled by housemakers and kids! Highly toxic products have no place being legislated into people’s homes, and CFLs are micro-units of special waste spread across peoples homes – the exact opposite of public health and prudent environmental science. When installed and utilized with just a fraction of care you suppose fluorescent lamps are handled with, incandescent lighting makes up a very small fraction of a household’s energy, and even electricity use.

    I sincerely recommend that both you and Jan Weaver read up on

    • paulrolfe permalink
      February 20, 2010 7:29 pm

      Absolutely, the energy industry and government should do more to lower emissions. Since they are not doing as much as people like you and I would like, it is responsible and a good idea to make changes in our own lives. CFL’s do reduce Hg emissions, especially when handled with the proper disposal techniques. People have control over whether they are poisoned with CFL bulbs.

      As far as safety concerns for homemakers and kids, education is key. There are a lot of dangerous things for children. It’s dangerous if they broke a regular light bulb too. Shards of glass are never safe. So, I understand the safety concerns many have and should have, but there are dangers everywhere and people should always be cautious. It would be fantastic if there were a better option. LED’s are excellent, but much more expensive than CFL bulbs at the moment.

      Thanks for the link, I don’t know exactly which section you were recommending though.

  2. Kathy permalink
    February 20, 2010 4:01 pm

    This is all great if you assume consumer’s dispose of the bulbs properly. The problem being of course that they don’t. Also what are the dangers in the home if a bulb breaks?

    • paulrolfe permalink
      February 20, 2010 7:13 pm

      If the bulb breaks in the home, the mercury will evaporate, so air out the house. Clean up the area and then dispose of the broken glass as you would normally with a CFL bulb (Hazardous waste disposal, just like paint or batteries). You would need to intake a large amount of mercury before any effects will occur, so there is not a great risk from one bulb breaking in your home. And it’s still safer than the mercury from coal. Thanks for asking 🙂

  3. otitismediamc permalink
    February 21, 2010 2:12 pm

    Again, CFLs by themselves do not reduce Hg emissions, and will quite obviously, in many instances increase Hg immissions, regardless of what people hope. Even using less electricity if your power supply is dirty-coal fired, even if all the hardcore green-minded households were to get off the grid and put a windmill and a biofuel power plant in their backyards, it would not decrease Hg emissions. The public will still need to force these plants to shut down or modernize, most economically done indirectly via emissions taxation.

    Education is the key, yes, but not for making all adults, children, housecats & dogs to become 99.9% proficient in HAZMAT routines regarding everyday appliances like lamps which is illusory. Look at how spent mercury-containing lamps really get handled around the world, and you will know why. But education may be the key for people to be able to get independent counsel or find out by themselves what is most uselessly wasting which proportions of fossile resources in their homes and lives. Very likely, the results will point to transportation, lack of insulation, oversized and outdated appliances, but NOT to some 35 watt incandescent reading and dinner table lights used for a few hours a day.

    You are wrong in telling Kathy that one would need to intake a large amount of mercury before any effects will occur. Your claim may be valid for acute effects. Hg is considered a highly toxic substance with any more human intake of any dose to be avoided. And yes, I do eat seafish which gets somewhat contaminated with airborne Hg from China and elsewhere, but that’s my personal choice, not a legislated one!

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