New Lightbulbs for a Better World, But What about the Mercury Content?

light-bulbfluorescent-bulb1As most of you are probably aware, there is a big push to change lighting from traditional incandescent lighting to fluorescent lighting. 95% of output energy from incandescent lighting is given off as heat as opposed to illumination. The most popular trend in “new light bulbs” are compact fluorescent lights (CFLs), which only require about 20 to 25% of the energy that incandescent light bulbs need to generate light. While CFLs are initially more expensive than traditional incandescent light bulbs, they pay for themselves with a significantly longer life, lasting ten times longer than incandescents.

However, while many people are pushing for the elimination of incandescent light bulbs, CFLs are potentially problematic; they contain mercury and currently 98% of used CFLs are not recycled. Mercury is extremely toxic to humans and especially toxic to unborn and developing children.

Mercury vapors in fluorescent lighting emit ultraviolet light when hit with a beam of electrons. The UV energy excites a phosphor on the inside surface of the glass tube, causing it to fluoresce and produce photons of visible light.”

A study was done that involved quantifying the mercury vapors that were released from broken CLFs. They found that over a 4 day period, a 13 watt bulb released 30% of its total mercury content. A conclusion from this study was that further sorbent-based technologies need to be developed for suppressing mercury vapor release from lamps such as CFLs.

This is a very interesting topic because the current energy and global warming crises have led scientists and engineers to find new paths to save the environment. CFLs, in my opinion, are a very good thing despite their mercury content because they decrease energy usage for lighting that WE ALL use every day. So, next time you are going to buy lightbulbs for the lamps in your residence and/or work place, think about the impact of the bulb you choose on the environment.

Comments (8) Add yours ↓
  1. skassel

    How much mercury is in an average CFL and how does this compare to the amount of background mercury we are exposed to every day?

    25 November 2008
  2. jaxtell

    A report from National Geographic News says that a switch to CFLs, and the resulting closure of coal-burning plants, will actually reduce mercury pollution.

    “For environmentalists, the clincher is that by requiring less energy, CFLs will actually cut down on mercury pollution produced by coal burning, and EPA agrees.

    ‘By using less electricity, CFLs help reduce mercury emissions from coal-burning power plants, which are the largest source of human-caused mercury emissions in the United States,’ said agency press officer Ernest Jones.”

    This article also gives suggestions for recycling these lightbulbs, which is said to recover 95% of the mercury. I agree with Meghan in that CFLs are a good idea. We just need to be sure to handle them properly.


    26 November 2008
  3. jsteves

    I knew that the fluorescent lightbulbs were more energy efficient, but I didn’t know that they contained mercury! I think that if the amount of mercury contained in these lightbulbs was unsafe (although I’m not sure if any amount of mercury can really be called “safe”), then they wouldn’t be on the market. I think Jon’s right–due to the mercury content, we need to know how to dispose of the lightbulbs properly. Now I know what to do when my fluorescent bulb on my desklamp finally burns out! 🙂

    28 November 2008
  4. csimmons

    I’m pretty sure the lightbulbs come with directions in case a lightbulb does break, but I know that the mercury content is small enough that as long as you don’t stick your face in the mercury and just let the room air out for the rest of the day after you clean up what you can, it’ll be fine.

    28 November 2008
  5. mhickey

    “As an illustration of the effects of CFL breakage, the release of only 1 mg of Hg vapor (?20% of the Hg inventory in a single CFL) into a 500 m3 room (10 × 10 × 5m) yields 2.0 ?g/m3 or ten times the ATSDR-recommended level of 0.2 ?g/m3 in the absence of ventilation”.

    29 November 2008
  6. mhickey

    Sorry, some characters in my above comment did not come through correctly when I copy and pasted the quote.

    “As an illustration of the effects of CFL breakage, the release of only 1 mg of Hg vapor (~20% of the Hg inventory in a single CFL) into a 500 m3 room (10 × 10 × 5m) yields 2.0 ?g/m3 or ten times the ATSDR-recommended level of 0.2 ?g/m3 in the absence of ventilation”.

    *The remaining “?’s” stand for micro.

    29 November 2008
  7. csimmons

    Alright, and with ventilation? Who in their right mind would leave the room closed up? Also, this test was probably done with no attempt at cleaning up the spill. Again, if it’s cleaned up as much as possible and then aired out it should be fine. I’m not saying that we shouldn’t care that there is Hg in the bulbs, it’ll be great if they can minimize the amount as much as possible, but the amount present now isn’t as dangerous as some people might make it out to be.

    29 November 2008
  8. pweibel

    As Jon said, a little bit of research shows that CFL’s actually reduce overall mercury pollution. However, it should be important to note than there are safe ways to dispose of CFL’s that don’t pollute the air with Mercury, people just don’t realize they need to do this: like with batteries. Also, you should all start putting your CFL’s away, and start buying LED light bulbs, which are ridiculously more efficient, and if my knowledge of LED’s is true, they will last longer. Here is a link to someone who sells them:
    As you’ll see they are pretty expensive compared to traditional light bulbs. But when they only take 2 W of power…

    30 November 2008

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