August 18, 2019, 03:58:35 PM
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Topic: Fire at Notre-Dame de Paris  (Read 828 times)

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Offline Enthalpy

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Re: Fire at Notre-Dame de Paris
« Reply #1 on: April 19, 2019, 07:52:26 AM »
Trying to estimate the lead concentration sent in the air by the fire...

Smelter workers had (in some places, have) harmful amounts of lead in the body due to lead's vapour pressure. If melting pure lead at 601K, the (equilibrium) vapour pressure is 10-11atm. If bronze molten at 1210K contains 10%Pb, the lead vapour pressure is 10-4atm.
https://en.wikipedia.org/wiki/Vapor_pressures_of_the_elements_(data_page)

In Notre-Dame's fire, the lead roofing melted around 600K, but the drops that landed on the burning oak beams didn't leave the flames. At 1400K, lead vapour pressure is 10-2atm. In addition, liquid or gaseous lead in the flames made oxides that went in the atmosphere as fumes, in amounts not limited by the vapour pressure. To my opinion, this is probably the yellow smoke that I never saw over a wood fire.

The firefighters may have inhaled noxious amounts, especially those who climbed in the towers. The nearby inhabitants downwind too. Inhabitants farther downwind and by-passers maybe; the smoke didn't fall down immediately, according to the pictures.

I consider prudent that all people who smelled the smoke clean the clothes they wore, and clean with a vacuum cleaner all surfaces of rooms whose window was open.

Some study mapping the amounts would be urgently needed, diagnosis in the firefighters' blood more so. Treatments to lead poisoning exist
https://en.wikipedia.org/wiki/Lead_poisoning
« Last Edit: April 19, 2019, 08:15:31 AM by Enthalpy »

Offline wildfyr

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Re: Fire at Notre-Dame de Paris
« Reply #2 on: April 19, 2019, 01:03:04 PM »
How is it possible to get this concern to relevant health authorities? Or find out if it's already being addressed?

Offline Borek

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Re: Fire at Notre-Dame de Paris
« Reply #3 on: April 19, 2019, 03:11:45 PM »
Yellowish smoke is not something unusual during fire, so I wouldn't search for too elaborate explanations without additional knowledge.

Actually I was surprised by how light the smoke was, I was expecting much more black one, with lots of soot.
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Offline Enthalpy

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Re: Fire at Notre-Dame de Paris
« Reply #4 on: April 20, 2019, 05:27:24 AM »
How is it possible to get this concern to relevant health authorities? Or find out if it's already being addressed?

French authorities will do everything they can to hide any problem, and will act only under people's pressure. The proper way is to inform the public.

Offline Enthalpy

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Re: Fire at Notre-Dame de Paris
« Reply #5 on: April 20, 2019, 05:49:35 AM »
Yellowish smoke is not something unusual during fire, so I wouldn't search for too elaborate explanations without additional knowledge.

Actually I was surprised by how light the smoke was, I was expecting much more black one, with lots of soot.

Stone-old dry oak burns cleanly. It go enough oxygen because the lead roofing melted quickly as the flames advanced. 5mm lead melting at 327°C in a big fire at >1000°C. A tin soldier doesn't last for long in a chimney neither, and 50m propagation in 1h leaves time.

I too wish I had more information, but:
  • From French authorities we won't get any sensible one. That's an absolute constant over history, whatever the regime.
  • The sooner poisoned people get a treatment, the better. Lead in the blood can be chelated, in the bones not.
  • It seems unavoidable that lead went in the fumes. Some remained in the fire, and then the vapour pressure let it evaporate. Can something prevent it?
  • There were >>100t lead as roofing, but 100µg in the blood are unhealthy. Many processes provide a path stronger than 10-9.
  • The roof materials weren't so diverse, from pictures before the fire. Oak and lead. Dry oak in chimneys doesn't make yellow fumes. β-PbO is yellow.

Offline Enthalpy

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Re: Fire at Notre-Dame de Paris
« Reply #6 on: April 20, 2019, 06:00:16 AM »
How is it possible to get this concern to relevant health authorities? Or find out if it's already being addressed?

French authorities will do everything they can to hide any problem, and will act only under people's pressure. The proper way is to inform the public.

The NGO Robin des bois tells much the same as I do. The French secret police insults it as an answer and threaten to cut the subsidies. The same spooks who insult and defame anyone revealing in France that wind energy is cheap. Don't expect France to work like the Netherlands or Switzerland.

Offline Enthalpy

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Re: Fire at Notre-Dame de Paris
« Reply #7 on: July 19, 2019, 12:20:25 PM »
I had said that the yellow smoke was lead oxide, it is known now that hundreds of metres around the cathedral are polluted by lead, even if newspapers still put "molten".
The dense smoke fell down as it cooled, as you can see it on the pictures. The first 100m are not the worse location.
I would have preferred to be wrong. Tons of lead powder spread over a city are a catastrophe. Newspapers begin to discover the cover-up by officials.

http://en.rfi.fr/france/20190718-paris-orders-clean-schools-near-notre-dame-over-lead-fears
https://www.france24.com/en/20190718-paris-orders-schools-near-notre-dame-cleaned-over-lead-fears
https://medicalxpress.com/news/2019-07-notre-dame-prompts-deep-schools.html
and the cited "investigation site" is nearly the only one in France that does more than pasting the AFP news
https://www.mediapart.fr/journal/france/180719/notre-dame-la-mairie-de-paris-passe-sous-silence-des-contaminations-au-plomb-dans-les-ecoles?onglet=full (in French, and pay)
some sites relay the information
https://www.nouvelobs.com/societe/20190704.OBS15446/notre-dame-de-paris-les-taux-de-plomb-au-sol-aux-alentours-explosent-les-compteurs.html (in French)
https://www.tellerreport.com/news/--notre-dame--worries-about-the-consequences-of-lead-pollution-.HJxrrbEhE.html

Between "10× some alert limit", "800× the legal limit", "child with lead levels in blood much higher than acceptable limits" and "astronomically high lead levels on adjacent roads, blood tests for children under 7 and pregnant women", the discrepancy is vast. I Emphasize that no "lead safe limit" exists.

Offline Corribus

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Re: Fire at Notre-Dame de Paris
« Reply #8 on: July 19, 2019, 02:11:02 PM »
Too bad you can't take blood samples from a representative population in Paris and coordinate the data to where they were at the time of the fire. In seriousness, the long term health consequences of a lead roof the size of the one in Paris aerosolizing during the fire could be very bad.
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

Offline Enthalpy

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Re: Fire at Notre-Dame de Paris
« Reply #9 on: July 22, 2019, 07:52:44 AM »
I can't take blood samples, the government won't, but other groups may.

What upsets me: I reacted that 3 days after the fire, other organisations about 2 days. It would have been the right time to clean the pollution and chelate lead in the blood of contaminated persons. But after 3 months, the lead oxide powder has largely entered the lungs of the inhabitants and visitors, and passed from the blood to the bones, from where removal is nearly impossible.

How much lead? The roof contained about 300t, but only a fraction evaporated in the fire. The whole lead melted and rained down. What fraction fell on wood, where the heat evaporated the lead, and the vapour made lead oxide carried in the atmosphere? Alas, the attic had a wooden floor above the stone arch, so whether this floor had disappeared before or after the roof melted decides the pollution amount.

If lead fell on the wooden floor, about all 300t lead went in the atmosphere. If the floor had disappeared first, only the lead falling on beams evaporated, which could be 10-2 or 10-3× the amount.

Anyway, the toxic concentration of lead in blood is about the same as for cyanide. If 0.3t cyanide had been injected in the atmosphere of a dense city, more people would worry about it.

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