LEDs and fluorescent lighting.

[eem2am]

Hello,


Fluorescent lights (eg the new CFLs) contain mercury and present a toxic hazard to humans. (?)

However, a recent court case in UK has proven that Mercury is not in fact very poisonous at all….

Between January and April 2009, William Dowling (69) of Colne, Lancashire , UK gave his ex-wife (Maureen) a cup of tea once a week, and he laced this tea with mercury.
His unsuspecting wife, Maureen, drank the tea and even remembers seeing silver globules in the bottom of the cup.

Maureen and the daughters eventually informed the police who raided William Dowling’s house and caught him red-handed trying to hide a pot of mercury.
They also found a coffee jar laced with mercury. William Dowling confessed to administering Mercury into his wife’s tea over the four months.

Maureen said that she had become ill with nausea and memory loss……..however, the court declared that Maureen’s illness was not likely to have been caused by the Mercury.

Willam Dowling was let off with a one year suspended jail sentence and is pictured in the Daily Express, 29th August 2009, page 17, with a huge smile on his face , walking free from court.

This Lady, Maureen, who drank Mercury for four months , is living proof that Mercury is not in fact very poisonous at all.

All I say is Rest-In-Peace mass mains lighting with LEDs.

Not only is LED’s competitor,( fluorescent lights containing Mercury), not very toxic, but LED lights need bigger heatsinks, are more reliant on electrolytic capacitors, and LEDs are more expensive.

Can we finally lay to rest the onset of domestic mains LED lighting?

 

[betwixt]

The toxicity of Mercury is not disputed - it IS a cumulative poison. The case you refer to used liquid mercury which is heavy and hence was found at the bottom of drinking cups and also has poor solubility. In compound form it is highly toxic and easily absorbed into human tissue. Had William Dowling been a chemist, the outcome would have been more tragic.

The biggest argument in favour of mercury based CFLs is that the fossil fuels burned to produce the power they use also contains traces of metalic compounds, including mercury. The justification for their 'eco'ness is that the amount they contain is less than the extra amount that would be released if an incandescent lamp was used. It's a lose, lose situation, mercury is used either way but CFL overall uses slightly less.

CFL and FL also contain relatively large amounts of phosphorous which is just as bad. They also contain electrolytic capacitors!

LED technology is probably where we will end up in a few years. It isn't as efficient as CFL but it's pretty close and the longevity of LED, together with it's lower toxicity will probably win the case for it. Time will tell.

Brian.

 

[Kral]

eem2am,
See the following for an eye opening experience.
**broken link removed**
http://www.masters-of-photography.com/S/smith/smith_minamata.html
**broken link removed**
Regards,
Kral

 

[eem2am]

http://www.timesonline.co.uk/tol/news/uk/crime/article6813673.ece

http://news.bbc.co.uk/1/hi/england/lancashire/8226473.stm

...these show a man who poisoned his wife with mercury but she is deemed to be ok.

 

[betwixt]

True, but it was also stated, I quote:

"That was not only a wicked way of treating your wife it was also potentially fatal. Fortunately your plan was discovered before any serious harm had been caused."

I don't think that implies that Mercury is safe, only that the dose she received did no obvious and immediate damage. In its liquid form, Mercury is difficult to absorb into body tissue, it is when it combines into other compounds which can be absobed that the danger increases. Note that in this particular case, liquid Mercury was spotted at the bottom of drinking vessels, hence not in solution or compound form. Mercury is very dense and surprisingly heavy if you have ever handled it, thats why very little was likely to have been consumed.

I state again, Mercury is extremely toxic, as are most heavy metals. It is a cumulative poison that builds up in the human body over time and primarily causes damage to the nervous system, causing loss of sensation, paralysis and eventually death.

The argument over using it in CFL devices has some merit but skips over the underlying toxicity problem. CFL does give an overall reduction in pollutants because of longer life before replacement and reduced energy production by-products but they are nevertheless dangerous and should be disposed of as controlled waste. The same applies to CCFL as used in LCD screen backlights and the light sources in document scanners.

Brian.