(This, of course, immediately made me think that you, or someone upstream from you, had just made the whole thing up, because that's what usually happens when people throw around unsourced quotes. Only my preternatural desire to not do anything productive or entertaining with what remains of my evening spurred me to continue the investigation.)

The document in question is titled "Shedding Light on Mercury Risks from CFL Breakage", and it can indeed be found on a Mercury Policy Project site of some description - mpp.cclearn.org, instead of their main www.mercurypolicy.org . Interested readers can download it from here (PDF).

Unfortunately, although the authors certainly do say that "hypersensitivity of the developing brain to damage from elemental mercury has been well documented in animal studies", they do not cite any such studies. It's also a bit odd that there's no human epidemiological evidence to be had - if this is actually the case - since quite a lot of epidemiological studies have been done on people who live in areas with lots of air pollution, and air pollution from coal-fired power stations, among other sources, is rich in elemental mercury.

And the Mercury Policy Project themselves don't seem to make this same claim anywhere else, which also strikes me as odd.

I can't, for a start, find it anywhere on the main Mercury Policy Project Web site. When I searched the site for "developing brain", I found they have a document called "Over the Limit: Eating Too Much High-Mercury Fish, dated October 2008 and authored by Edward Groth and Eric Uram, here (PDF). It's about methylmercury, which you'll recall I agree is a very toxic substance, but it doesn't seem to mention elemental mercury anywhere. If they think elemental mercury's a big deal, you'd think they'd have mentioned it.

The only other mercurypolicy.org hit for "developing brain" was a link on this page, to a paper (PDF) titled "Public Health and Economic Consequences of Methyl Mercury Toxicity to the Developing Brain". Which, again, ain't about metallic mercury; they mention metallic mercury, but only because elemental mercury pollution that finds its way to the appropriate bacteria can be turned into methylmercury. Which, once again, is bad news.

Switching the search to mpp.cclearn.org, I found the CFL-breakage document, two more documents warning about methylmercury, and two documents that mention the possible dangers of mercury fillings. Read charitably, they recommend the application of the precautionary principle, which in this case apparently means avoiding mercury-amalgam fillings that provably outgas very very close to zero mercury - well, compared with the amount of mercury you inhale every day from normal suburban air, anyway. Instead, I suppose you should insist on gold, no matter how expensive it is, because I'm sure nobody this dedicated to the precautionary principle would recommend those strange and untested composite fillings composed of synthetic resins with names as long as your arm.

The authors you mention also don't seem to have any collaborative works listed in Medline. I'm no Medline search ninja, but I've done a few searches now and haven't found anything from anybody else that support your statement, either. I mean, apparently you can probably tell, by dissecting fetuses, if pregnant rats were exposed to four hours a day of air contaminated with 300 micrograms of metallic mercury per cubic metre; since that's one thousand times the Main Ambient Air Guideline of 300 nanograms per cubic metre, I'm not bloody surprised.

It's not hard to find hits for a search vaguely connected with with developing brains and mercury hypersensitivity; here's a jumping-off point. The results that're actually relevant all seem to be talking about organic mercury compounds or large doses of metallic mercury, though. Do please tell me if you strike oil on results page 19, or something.

Oh, and since we seem to be playing the Duelling Experts game with an added coda of Make The Other Guy Humiliate Himself 'Cos He's Wrong, Wrong, Wrong, I hereby require that if your allegation turns out to be misattributed, fictional, published in the Letters section of a medical journal and then misleadingly claimed to have been "published in a peer-reviewed journal", et cetera, you must drop your pants and run seven times around the pool table singing "I've Got A Lovely Bunch Of Coconuts".

You may select a clockwise or anticlockwise run according to your personal preference.

The words of people who actually know:
"There is no comparable body of epidemiological
evidence on the effects of mercury
vapor in the very young, but an analogous
hypersensitivity of the developing brain to
damage from elemental mercury has been
well documented in animal studies."

• Edward Groth, PhD, Groth Consulting Services, Pelham, NY
• Alicia Culver, Green Purchasing Institute and
• Eric Uram, Headwater Consulting / Sierra Club – National Environmental
Quality Strategy Team.

Mercury Policy Project
1420 North St.
Montpelier, VT 05602
www.mercurypolicy.org
©2008

Now, your job is to admit your ignorance and advise your readers.

The EU incandescent-lamp ban, to choose one example, does indeed have a 2012 deadline. But member states are left to their own devices as to how they enforce this. Some are banning sales of incandescent lamps altogether; others, like Britain, have a voluntary phase-out, starting with hundred-watt bulbs.

I need to know why you think the ban will, in fact, make it impossible to buy incandescent bulbs of all sorts in all - or even most - of the EU by 2012. Given the usual degree to which nations conform to international agreements - even ones having to do with very important things like human rights and inhumane weapons, never mind just light bulbs - I'd find it very surprising if incandescent bulbs actually became impossible to at least buy in batches on eBay from overseas, even in countries that ban their sale locally.

I also expect to see exceptions made, in at least some nations, for specialty bulbs that cannot be had in more efficient versions, and whose contribution to the overall energy budget is not large. Take purpose-built heat lamps, for instance. (Apparently it actually is possible to buy compact fluorescents that fit in standard 375W heat-lamp sockets - this of course means your bathroom heater doesn't heat any more. :-)

And even if it really does become impossible, or unreasonably impractical, to buy ordinary incandescent bulbs in many nations, a deadline of 2012 strikes me as one that gives a decent amount of time for usefully bright and affordable (especially when you take into account their very long lifespan) LED lamps to arrive.

So I just don't see what the big problem is, Kevan. Please support your argument with references if you choose to continue.

There are now a number of efficient Tungsten Halogen incandescent lamps appearing in the market. They offer at least 30% direct energy saving with none of the risks associated with CFLI however the EU legislation will ban these as well!

Kevan Shaw

[EDIT: It now occurs to me that LED lamps will be a good option for almost all of these situations. They're still not quite cheap and bright enough for use as a bathroom light, even when you consider the fact that they'll probably last pretty much forever, But super-LEDs are already quite able to substitute for the low-wattage bulbs that illuminate the insides of fridges and microwaves. You probably can't yet buy an LED lamp with the right dimensions and base to fit in those little nooks, but as soon as even a half-hearted "incandescent ban" is legislated somewhere big, Chinese factories will start pumping out LED fridge bulbs.]

I doubt, however, that incandescent-bulb bans will be so thorough that it will actually be impossible to buy bulbs for these purposes. Perhaps the EU one really will be; I don't know.

The foundations of the PLDA's complaint seem to me to be a scattershot collection of factoids, not all of which are true. Among the statements which I think are invalid:

* CFLs are unsuitable for use on dimmer-switch circuits. This is true for common-or-garden CFLs; if you've got the usual kind of little-buzzing-knob dimmer, you have to remove it altogether from the circuit, not just leave it turned up to max. But it is now possible to buy dimmable CFLs, reducing this problem to a minor nuisance.

* "The ballast power factor is very poor." It's my understanding that it's now quite difficult to buy a CFL with a lousy power factor; power-factor correction circuitry is standard equipment for modern CFLs. I suppose the PLDA ought to know more about this than I do, but they don't seem to mention corrected CFLs at all, which strikes me as odd.

* No organised way to recover or recycle the lamps. True, but not very relevant. I think it's not a bad deal to get a little metallic mercury going into landfills in return for not burning a lot of coal, which creates several different flavours of air pollution, and of course lots of CO2. If you prefer the air-pollution option, put your old CFLs in a bucket, take it outside, and smash 'em with a brick; the mercury will all have wafted away in a minute or two, and you can drop the remains in the bin.

* Disturbance of sleeping patterns, zero effect on real carbon emissions because of carbon-trading systems that already exist: Now I think you're just being silly.

People with CFL bedside lamps are not all suddenly being stricken with insomnia, and I think your understanding of cap-and-trade systems is defective. Yes, organisations subject to emissions-trading systems like the EU one are, in the aggregate, still going to emit as much as the system allows them to, but the whole point of these systems is to reduce pollution by slowly reducing the cap, and it won't be possible to do that if nobody saves any bloody power. The more CFLs and other emissions-reducing devices people install, the lower will be the industry pressure to keep the cap high.

(And you can too use CFLs in enclosed outdoor light fittings. I do here. They may never warm up and start glowing properly if you're using them in a winter in most of the EU, but in warmer climates - including some of the EU - they work just fine.)

The only documents I can find say that environmental mercury is significantly reduced by the use of CFLs, because lower power consumed means less coal burned. I've also never heard these claims about manufacturing energy and waste. Obviously a CFL is a more complex object than an incandescent globe, but I find it hard to believe that the difference outweighs the fourfold power-consumption difference, especially given that CFLs can last a lot longer than incandescents.

Real problems occur in landfill when the microbes present convert the mercury to methyl mercury that is water soluable and 20 times more poisonous to higher life form than metallic mercury.

So don't break them and do recycle them if you csn suffer them in the first place!

By the way according to research carried out for the European parliament it takes 12 times the energy to manufacture a compact fluorescent energy saver lamp that it does to manufacture an incandescent lamp. The study also shows that only 5 grams of waste are produced during the manufacture of an incandescent lamp whereas 112 grams of waste of which 78 grams are hazardous are produced in the manufacture of a compact fluorescent that typically weighs 80 grams!

Kevan Shaw Direstor of Sustainability for the Professional Lighting Designers Association