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Mercury emitted from coal-fired power plants comes from mercury in coal, which is released when the coal is burned. While coal-fired power plants are the largest remaining source of human-generated mercury emissions in the United States, they contribute very little to the global mercury pool. Recent estimates of annual total global mercury emissions from all sources -- both natural and human-generated -- range from roughly 4,400 to 7,500 tons per year. Human-caused U.S. mercury emissions are estimated to account for roughly 3 percent of the global total, and U.S. coal-fired power plants are estimated to account for only about 1 percent.
EPA has conducted extensive analyses on mercury emissions from coal-fired power plants and subsequent regional patterns of deposition to U.S. waters. Those analyses conclude that regional transport of mercury emission from coal-fired power plants in the U.S. is responsible for very little of the mercury in U.S. waters. That small contribution will be significantly reduced after EPA’s Clean Air Interstate Rule and Clean Air Mercury Rule are implemented.
U.S. coal-fired power plants emit mercury in three different forms: oxidized mercury (likely to deposit within the U.S.); elemental mercury, which travels hundreds and thousands of miles before depositing to land and water; and mercury that is in particulate form.
Because mercury can be transported thousands of miles in the atmosphere, and because many types of fish are caught and sold globally, effective exposure reduction will require reductions in global emissions.
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Consequently, there is guaranteed exposure to mercury from emissions, and in substantially large quantities than from a little chance of broken CFL (and even then, the mercury content is quite little).
You're missing the point, this is very small area where mercury vapor is being concentrated. Again the only question is how many bulbs before that exposure becomes greater.
It quite simple, more mercury is emitted due an incandescent bulb being used than is present in a CFL to begin with. Even the GEICO caveman can do that calculation.
Again, you are evading the issue. You are auguring points in a fashion that is devious and misleading.
As Coleman said, dispersion and level of exposure at contact is the issue. Exposure of toxins below a certain level can be safely filtered by the body in most cases.
The issue with these bulbs is that on the moment of them being broken, the permissible exposure limit and threshold limit value spikes to levels which are deemed harmful.
Mercury concentration in the study room air often exceeds the Maine Ambient Air Guideline (MAAG) of 300 nanograms per cubic meter (ng/m3) for some period of time, with short excursions over 25,000 ng/m3, sometimes over 50,000 ng/m3, and possibly over 100,000 ng/m3 from the breakage of a single compact fluorescent lamp.
You are arguing overall release through the entire life process of the technologies and then attempting to claim one is worse than the other while ignoring the immediate exposure limits in the situations upon a broken bulb in a home or building.
You argument has no bearing on the context of my discussion.
If you wish to object to the issue, you will need to provide proper citation that deals with the research I have provided in the context it does.
You're missing the point, this is very small area where mercury vapor is being concentrated. Again the only question is how many bulbs before that exposure becomes greater.
/sigh
Unfortunately, I am beginning to think that is their intent.
Yes but overall mercury emissions are global issue, US coal fired plants account for 1% of global pool.
It doesn't matter, considering there is as much a chance of getting same, if not more, amount of mercury from seafood you and I consume as there is a possibility of if we happen to break open a typical CFL.
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You're missing the point, this is very small area where mercury vapor is being concentrated. Again the only question is how many bulbs before that exposure becomes greater.
Why is it more of a threat than Albacore Tuna at a grocery store?
It doesn't matter, considering there is as much a chance of getting same, if not more, amount of mercury from seafood you and I consume as there is a possibility of if we happen to break open a typical CFL.
You're suggesting this or have a reference? I've only briefly looked over the study from Maine Nomander referenced which provided a wide variety of circumstances where a bulb may be broken but I did not see any reference comparing it to other sources.
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Why is it more of a threat than Albacore Tuna at a grocery store?
It's going to depend on the circumstances and the amount of exposure, as I said it's not a matter of if it is but how many bulbs and the circumstances. The Maine study did comparisons between breaking one in ventilated room, unventilated, where a vacuum was used etc. While on the topic not sure if they still do but in the past the EPA suggested using a vacuum for cleanup which I've always questioned. The Maine study shows significantly higher contamination and continued contamination using a vacuum.
You're suggesting this or have a reference? I've only briefly looked over the study from Maine Nomander referenced which provided a wide variety of circumstances where a bulb may be broken but I did not see any reference comparing it to other sources.
I haven't seen comparisons either, just numbers and the fact that people have been consuming mercury via seafood. Link
I've eaten a LOT of seafood and have never dealt with a broken CFL since I switched to them about seven years ago. Whether you're in an area with strong mercury related emissions, or dealing with water/seafood with mercury, the chances of your mercury consumption is much greater through these sources (air, water, food) than from breaking a CFL or an LCD screen on your TV, computer screen, cameras, cell phone, air conditioning units, gas/electric ovens, neon lights, HID lights (my current and last car has it and becoming more common)... and if you happen to have an old fashioned (not digital) thermostat anywhere around, take a look at the amount of mercury used in that thing. And we're to be worried about 4% of the small mercury content used in a CFL (0.16mg) that one may not break in a lifetime?
Last edited by EinsteinsGhost; 07-18-2011 at 10:57 AM..
And we're to be worried about 4% of the small mercury content used in a CFL (0.16mg) that one may not break in a lifetime?
<sigh> The only point I'm trying to make is that DCforever and yourself are trying to use overall emissions as a basis for your argument. Nomander has brought up a very significant point because the exposure is going to be greater. Without a good comparison you can't come to any conclusions.
As far as breaking one inside a home I've never broken any of the small ones but have broken plenty of the larger tube ones. I have quite a large scar on my one finger about an inch long brought on by my lighting fast reflexes. One fell from the ceiling and I was able to catch it midair, damn thing smashed into the wall and shattered.
<sigh> The only point I'm trying to make is that DCforever and yourself are trying to use overall emissions as a basis for your argument. Nomander has brought up a very significant point because the exposure is going to be greater. Without a good comparison you can't come to any conclusions.
Prove it.
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As far as breaking one inside a home I've never broken any of the small ones but have broken plenty of the larger tube ones. I have quite a large scar on my one finger about an inch long brought on by my lighting fast reflexes. One fell from the ceiling and I was able to catch it midair, damn thing smashed into the wall and shattered.
Is that more exposure to mercury from FL than from lifetime of exposure from air, water and seafood?
I haven't seen comparisons either, just numbers and the fact that people have been consuming mercury via seafood. Link
I've eaten a LOT of seafood and have never dealt with a broken CFL since I switched to them about seven years ago. Whether you're in an area with strong mercury related emissions, or dealing with water/seafood with mercury, the chances of your mercury consumption is much greater through these sources (air, water, food) than from breaking a CFL or an LCD screen on your TV, computer screen, cameras, cell phone, air conditioning units, gas/electric ovens, neon lights, HID lights (my current and last car has it and becoming more common)... and if you happen to have an old fashioned (not digital) thermostat anywhere around, take a look at the amount of mercury used in that thing. And we're to be worried about 4% of the small mercury content used in a CFL (0.16mg) that one may not break in a lifetime?
Yet part of the point is that we are implementing technologies to which contain such a hazard to replace technologies that did not contain such under the same circumstances. You break an incandescent light and the risk is that of not cutting your finger as opposed to its replacement now having a mercury exposure hazard. That study is simply showing that the exposure level of simply breaking one in a closed room has severe spikes above that of safe exposure.
Now you may have never broken one, but most of us at some point in our lives have broken an incandescent in some fashion or another. Some people have such accidents more often than others and this trend will likely not change when all incandescent are replaced by CFL. Also consider that these lights are being replaced in numerous household components and as such increases, the chance of random breakage increases as well. I don't think everyone wants to treat every light source as if it were a class 1 hazard.
The point is that while I understand your position that we are all exposed to mercury through other products, the levels of such exposure are key and the research is showing that those levels under those situations are well above what is considered safe. As for the others, those need to be assessed individually case by case and not though anecdotal excuse concerning the hazard these may provide. The fact though that we have exposure in various forms is not justification to increase that exposure in more products. By doing so, we may elevate the exposure to a point where it can become a major issue of noticeable significance.
There is no reason to crusade the position of CFL bulbs when there are other technologies available. The only benefit is that with CFL, due to its costs being the least between the newer technologies, it can be used to promote political change with mandates without too many people (who are not informed to the details of them) having major objections.
Personally, Mercury is simply one problem with them, their ballast encapsulation issues are another hazard as well and when a replacement technology has multiple increased hazards over that of its previous technology, it is simple common sense as to the choice of which one is appropriate.
Is that more exposure to mercury from FL than from lifetime of exposure from air, water and seafood?
Measuring exposure comes in amount/time exposure. In some toxins, exposure of a small amount over long periods of times may have no significant dangers. Depending on the toxin, the time and amount will change to such.
The tests conducted in the study I linked was testing immediate exposure levels to which safety exposure limits to 300ng/mⁿ, ⁿ=3. If you are exposed above that, it is harmful and the tests show some spikes of up to 25,000ng. Which I hope you can see the concern.
It is like radiation. We experience exposure to radiation everywhere we go as it is a basic principal of the world. The issue is how much you are exposed to and the time to which you are exposed to it. Mercury in that aspect is similar. Now certainly you can argue over those PELs, but you would also have to establish the level of exposure of other sources before you made such a comparison. That said, I think that it is safe to say that if 300ng is safe, 10,000 to 25,000ng/mⁿ, ⁿ=3 can't be good.
Last edited by Nomander; 07-18-2011 at 01:10 PM..
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One fell from the ceiling and I was able to catch it midair, damn thing smashed into the wall and shattered.
