Lead Poisoning

[Derek Geldard]

OK.

Be fair, the posting was in uk.d-i-y on the topic of the safe removal of lead bearing paint ! For that purpose it was accurate enough IMO, even if unbalanced in the face of conflicting opinions.

The trouble for a layman reading this topic up nowadays is the amount of single interest group propaganda (mostly anti vivisectionist) out there. In any event it is always difficult to differentiate between conspiracies and c*ck-ups.

Having checked, I accept that nowadays the conventional wisdom is that the Thalidomide disaster was as a result of a c*ck-up. They marketed a drug for the treatment of Morning Sickness in Pregnancy and didn't test it on pregnant animals. What is more, the regulatory agency (whoever it was at the time) failed to protect the public from this. This seems scarcely credible from today's perspective and feeds the conspiracy theories.

OTOH A report I read (can't find it now, conspiracy theorists, no doubt) said they tested it and discarded unfavourable results.

The anti-vivisectionists say that even if they had tested it on pregnant animals then it wouldn't have revealed any hazard.

I note from my reading that the FDA never allowed Thalidomide to be prescribed in the USA because they were not satisfied with the rigor of the testing in Europe.

All that said, I'm sure you wouldn't want to let any of this give succour to people who say that Lead may not be toxic because medical testing is not reliable.

And finally, I'd just add that my cousin had a baby sometime around

1961 which was stillborn with deformed limbs, she had been taking Thalidomide. The midwife said they (at the maternity hospital) couldn't understand what was happening, they had been "overwhelmed" with babies with deformed limbs over the previous fortnight, presumably when all the involved pregnancies started to come to term.

DG

[Andrew Gabriel]

Talking of which, I came across a couple of interesting cases.

One was a child, who eat a couple of lead soldiers. For that short time, his body was probably way over any permitted lead dosage, but it passed without anything notable at the time AFAIK. It came to light a number of years later when he was xrayed. There were no lead soldiers visible, but the excess lead was depositied in his growing bones at the growth plates. The bones continued growing normally afterwards, but xrays showed an opaque plate a certain distance back from the ends in each bone at what had been the tips of the bones (growth plates) at the time he eat the soldiers. As such, it was a good demonstration of how bones grow.

The second case was that of someone who was shot but not killed. Bullets are often not removed when they are not in a position to do physical harm. The body detects an alien object and grows a covering round it to protect the body, which is normally very effective. One place where this turned out not to work was a bullet which is near a bone joint. The synovial fluid turns out to be a good solvent for lead, allowing it to disperse continuously throughout the body and cause slow lead poisening.

[Denn013]

Re - lead poisoning - how about mercury? when I was a kid in the fifties my dad and uncle were elctrical type guys who cobbled together all sorts of gadgets that actually worked. I used to love playing with the mercury - rolling it about on the floor - watching the globules all find themselves and join together. I would push it all together with my fingers and eventually get it back in the jar. I became an Electrical Engineer and in 1971 sold a mercury switch these guys had made to a factory which was shut down for lack of one. By then mercury was banned. I got £100 for the switch - I still have one. I am still here and have probably been exposed to this stuff more than most - but I have no problems - ha ha ha he he he he.

Health and Safety and experts all gone way over the top (in pursuit of money of course) ha ha ha

[dennis]

Try burning the stuff and breathing in the vapours and you might feel different. Or maybe a nice organic compound?

[Mark Spice]

Google for Minamata Bay for a nice (?) example.

Metallic Hg is relatively benign as it is not absorbed that well from the gut, make it more lipophillic by adding a methyl group (CH3) and it can cross lipid membranes like the blood-brain barrier. At this point it is metabolised back to Hg and so cannot cross out of the brain and so it accumulates causing toxicity to the CNS.

Cheers

Mark (the ex-toxicologist)

[meow2222]

thanks for the link. Removal was using a hot air gun, which is an inappropriate method for removal of lead and arsenic bearing paints. Removal using gel creates larger particles and traps them in the gel instead of creating fine particles and blowing them round the place, as a hot air gun does.

NT

[meow2222]

I cant help but wonder when someone claims a job thats perfectly diyable must only be done by a professional. No evidence of risk of gel stripper removal of lead paint was presented, and it is hard to see how the precautions recommended would be appropriate for any appropriate removal method, ie gel paint stripper.

NT

[Weatherlawyer]

Any comparison with medical practices then and now was inviting silly comment to go with your OP.

Anyone working in a factory anywhere in the UK, was liable to any amount of serious illness all unexplained by the death certificate. These days the opposite is true with anyone entering hospital likely to get dead for their cure.

Why do you think that the cotton industry moved to India after centuries of employing western Europeans at the huge rate disparity between Asian and European pay rates?

All of a sudden people were getting the idea that there was a conspiracy in the industry about the numbers of deaths due to cotton dust in the factories. And overnight the factories "couldn't compete".

A recent report has been released in the Stoke on Trent area, showing that after decades of being the most dangerous place to have children, other hospitals in the country have caught them up.

(The incidence of mentally damaged people here outnumber those of any other place I have been, all due to techniques used in maternity units here.)

[HLAH]

Mercury poisoning has been shown to cause severe top-posting in test subjects ;-)

H

[The Medway Handyman]

Lead flashing? I'll send the local pikeys round :-)

I don't suppose they care about H&S when nicking it!

[Tim Lamb]

In message , Andrew Gabriel writes

What does Zinc do to you?

Perfect ventilation is not really practical welding large work pieces, farm gates etc. I was angle grinding the corners off some galvanised brackets today and watched the Zinc fume off with a purple flame.

regards

>

[AJH]

Zinc oxide fumes are a cumulative poison. In small doses the effect is headaches and flu like symptoms. Do a google on welder's fume fever.

is a high hit.

Easily overdone even working outdoor.

AJH

[Mark Spice]

There appears to be a dose response relationship with inhaled ultrafine zinc-oxide powder (at least in guinea pigs) - this leads to increased airway resistance and decreased volume. This experiment was looking at acute doses (dosed for a week). (1)

"The type of lung disease caused by metal compounds depends on the nature of the offending agent, its physicochemical form, the dose, exposure conditions and host factors. The fumes or gaseous forms of several metals, e.g. cadmium (Cd), manganese (Mn), mercury (Hg), nickel carbonyl (Nl(CO)4, zinc chloride (ZnCl2), vanadium pentoxide (V2O5), may lead to acute chemical pneumonitis and pulmonary oedema or to acute tracheobronchitis. Metal fume fever, which may follow the inhalation of metal fumes e.g. zinc (Zn), copper (Cu) and many others, is a poorly understood influenza-like reaction, accompanied by an acute self-limiting neutrophil alveolitis." (2)

The short answer would appear to be that you may get flu-like symptoms from inhaling too much Zn dust. However overall Zn appears to be relatively benign compared to the heavy metals like Pb and Hg. I'd suggest using a mask and/or ventilation where practical.

Cheers

Mark

(1) Pulmonary function of guinea pigs exposed to freshly generated ultrafine zinc oxide with and without spike concentrations. Lam HF et al. American Industrial Hygeine Association Journal 1988

(2) Metal toxicity and the respiratory tract. Nemery B. The European Resipirtory Journal 1990

[The Medway Handyman]

No idea Tim - but you probably won't ever go rusty :-)

[Tim Lamb]

In message , AJH writes

That explains Monday mornings:-)

Current weather makes outdoor work a pain anyway.

I have fitted the barn trusses using my patent fork lift extension and am currently dodging between fitting purlins and pre-painting feather edge boarding as showers permit.

regards

[Tim Lamb]

In message , Mark Spice writes

I certainly recognise the headache/flue symptoms following this sort of work. Rust dust also gives a rapid headache but responds to a simple filter mask.

Fumes from galvanised material tend to be vapour so presumably need something more sophisticated and hence bulky. Gas welding wearing reading glasses is an acquired skill:-(

regards

[Andrew Gabriel]

What, a bit like this?

am currently dodging between fitting purlins and pre-painting feather