GreenLightsBlog

One of the big (manufactured, in my opinion) controversies about CFLs is the mercury contained in them.

For a while, I’ve avoided touching this issue because it’s, well, touchy.

I confess that I have a (hopefully unfounded) fear that sensationalism rules the public and that the mere mention of mercury (ohh no! isn’t that toxic stuff!?) will simply drive the masses to unthinking and fearful avoidance.

Hahahaha, again, please don’t think I’m accusing you of being unthinking - what I’m confessing is an unfounded fear.

So, now that we’ve asserted that we’re all adults capable of rational discussion, what are my thoughts?

Short, to-the-point answer: the mercury contained in CFLs is too minute to be harmful for your health or your family’s health, even if you break a few. Heck, even if you break a bunch! You’d have to break 20 CFLs at once to get the same amount of mercury as an older-style thermometer.

Also, because CFLs save energy which is oftentimes generated from burning coal in the U.S., and burning coal releases mercury, CFLs actually reduce the amount of mercury going into the environment.

Longer answer, for those who want to think this through more thoroughly: the thing to know about mercury is that it comes in more than one form. Elemental mercury is the liquid metal stuff that we’re all familiar with. The thing to know about elemental mercury is that it’s not very dangerous. It’s not very dangerous because the body doesn’t tend to absorb it, so it never gets anywhere where it can do harm.

When elemental mercury is present in the environment, say in a lake, in sufficient amounts, something happens.

Small organisms (say, small fish) living in the lake will absorb a small amount of mercury, and it will be converted in their bodies to methylmercury, an “activated” organic form of mercury that is absorbed into the body, and is retained in the body better (worse?) than elemental mercury.

The small fish themselves generally won’t actually be affected by the methylmercury in their body, because it’s not present in very high concentrations.

Now something really interesting happens. The organism that preys on the small fish, say a medium-sized fish, will have to eat 100’s or even 1000’s of small fish in its lifetime in order to survive. Because the activated methylmercury is absorbed and retained in the body well (in contrast to elemental mercury, which is not), the medium-sized fish will have a much higher concentration of methylmercury in their body than the small fish did.

This continues along every step of the food chain, so that the higher you go, the higher concentration of methylmercury is present.

Well, guess who’s at the very tippety-top of the food chain? (= You guessed it! Lucky us! Homo sapiens.

So in communities that may eat seafood as their staple, people may eat 100’s or 1000’s of relatively large predator fish, thereby ingesting a supply of heavily “bioconcentrated” organically activated methylmercury, resulting in birth defects and other undesirable things in communities that eat fish from mercury-contaminated lakes.

Hence, the legitimate concern about mercury in the environment, which due to very significant amounts of bioconcentration and bioactivation, may result in birth defects in humans, especially in polluted lakeside seafood-eating people.

So where does this leave us with CFLs?

One conclusion is that the minute amount of unactivated elemental mercury present in CFLs is a far cry from a health concern. In fact, you may be surprised to learn that, if you have any of those silver-colored fillings in your teeth, you probably have, not 20, but 200 times as much mercury in your mouth as is present in a CFL!

The second conclusion is that because each 5mg-of-mercury CFL prevents significantly more than 5 mg of mercury from being released into the environment from burning coal, if you’re concerned about mercury in the environment, or mercury contamination, you should actually use as many CFLs as you can, and encourage everyone else you know to use CFLs also! Doing so will reduce the amount of mercury released into the environment due to burning coal for energy, even net of the amount that’s inside the CFL itself.

So there you have it. (=

Eddie Chu
Founder, GreenLights

Filed under: Uncategorized on October 5th, 2007