As of 2005 in the US, 49.7% of Electrical Generation was from Coal. So, I guess for a US average we could take the mercury figures above and cut it roughly in half.
FRDE, DrDeth, What Exit?:
I’m not a chemical engineer, so I’m not sure if coal plants have to discharge mercury. Facts are that they do discharge mercury, so I’m still fine with that “assumption”.
Even if you go with 1/2 of power coming from coal using the 10mg amount, and the other half generated in some manner that creates 0 mercury pollution, then the numbers are:
Incandescent:
5mg to light, + ~0 to manufacture = 5mg of mercury. (All of it released into atmosphere)
CFL:
1.2mg to light, + 4mg to manufacture = 5.2mg of mercury, less than 1/4 of it released if you find a waste depot.
Then of course there’s sulphur dioxide, nitrous oxide, carbon dioxide, etc. etc. Still CFL FTW.
Of course, those of us who care enough about the environment to pay extra for our electrical power to make sure it’s 100% wind generated can’t take advantage of the particular trade-off … Have to think about disposal, I think.
Don’t get me wrong. I recycle my fluorescent bulbs, tubes and CFLs. I use Solar Panels to generate about 75% of my power. I was just defending the logic that says the threat of Mercury waste from CFLs is less than the threat from the average power consumed by the incandescent bulbs replaced.
I thought Nanodahad raised a good point that made sense.
This isn’t so much in reply to your point, but your point made me think of a question of my own, so that’s why I’m quoting you - to let others see my train of thought.
So where does the mercury come from in the first place? And isn’t it safer in the long run to return that mercury into the earth and its filtration systems involving soil and water, instead of into the air like (coal) power plants do?
And, for that matter, aren’t landfills “locked up” anyway? I thought the reason that even our biodegradable stuff isn’t degrading is that landfills are sealed and filled in so that sunlight and water can’t do their degrading thing. While I wouldn’t assume they’ll be hermetically sealed forever, it just seems like locking the mercury away in glass tubing, then in a garbage bag, then in a sealed landfill for a good long time is better than spewing it into the air. But I might be wrong about that.
In most States, it is fine for compact fluorescent lamps, considered household hazardous waste, to be disposed of in household garbage. This is because most garbage in the US goes to municipal solid waste landfills which are lined and capped. The leachate (liquids that have percolated through all the garbage) is tested and treated as hazardous waste, if necessary.
This is not the case in areas where garbage is incinerated or in States with more stringent environmental regulations like California. In places where CFL cannot be disposed of in household garbage, contact your local mayor’s office about household hazardous waste drop-off sites or go to www.earth911.org to find the nearest recycler.
However, mercury in landfills is converted to methyl compounds, which come out in the dump’s methane plumes, not the leachate.
Also, much of the mercury in a lamp actually comes out when the lamp breaks, before reaching the landfill. However some remains bound to the phosphors.
Someone here read my mind again. I’ve been switching to the CFL’s and when I went to throw the “box”* away recently I saw the little note about them containing mercury and wondered how that could be good for the environment. So thanks for this thread!
I think I’ll keep using them because they do last longer. I’ll just set aside a spot in the garage to collect used ones for hazardous disposal but it doesn’t look like I will need to be doing that very often. I noticed that they do start out dim when turned on, then get brighter (and I’m in a very warm climate) and I actually like that because I hate walking into a dark area and having my retinas blasted when I turn on the light.
*This brings up another concern. These lights are always sold in these heavy duty almost impossible to open plastic packs. How is that good for the enviroment? At least incandescent bulbs are packed in recycleable/biodegradeable cardboard.
Yeah, that was my point.