Fire in Notre Dame in Paris

[michel123456]

17 hours ago, Enthalpy said:

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".
I had said that the dense smoke had fallen down as it cooled, and 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.

en.rfi.fr - france24.com - medicalxpress.com
and the cited "investigation site" is nearly the only one in France that does more than pasting the AFP news
mediapart.fr (in French, and pay)
some sites relay the information
nouvelobs.com  (in French) - tellerreport.com

Between "10 times some alert limit", "800 times 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 underline that no "lead safe limit" exists.

It is worth noticing that they use robots for taking the scrap out. Pictures from an article in Greek newspaper https://www.kathimerini.gr/1034458/gallery/epikairothta/kosmos/etsi-sw8hke-h-notr-ntam-apo-thn-katastrofh

[swansont]

Robots use could be because of physical danger from e.g. falling debris.  

[Enthalpy]

On 7/19/2019 at 6:46 PM, swansont said:

Robots use could be because of physical danger from e.g. falling debris.  

That's what French officials allege too... But the cathedral square is closed because of lead pollution.

It were about time to admit that the site is a toxic waste, and complete Parisian districts are polluted. The attempted cover-up by French officials reminds every French old enough the Chernobyl catastrophe, as the radioactive cloud allegedly stopped at France's borders.

Fire in April. Many people told quickly "yellow smoke is lead, toxic, decontaminate" - here on 18 April. In July, the officials start to react only because the scandal grows. This is exactly how the French citizens know their government will behave.

[John Cuthber]

OK, so people seem to be saying that because the lead fell down and polluted the floor, it went up and polluted the sky.

OK...

[dimreepr]

3 hours ago, Enthalpy said:

That's what French officials allege too... But the cathedral square is closed because of lead pollution.

A conspiracy theory? I thought better of you... 

[swansont]

5 hours ago, Enthalpy said:

That's what French officials allege too... But the cathedral square is closed because of lead pollution.

There are workers in one of the pictures. Clearly, they can access the area with proper safety equipment, e.g. air filtration masks and bunny suits, which mitigates the immediate risk from lead. 

5 hours ago, Enthalpy said:

It were about time to admit that the site is a toxic waste, and complete Parisian districts are polluted. The attempted cover-up by French officials reminds every French old enough the Chernobyl catastrophe, as the radioactive cloud allegedly stopped at France's borders.

One article says that they did not test the regions until May, which sounds more like incompetence than a coverup. 

5 hours ago, Enthalpy said:

Fire in April. Many people told quickly "yellow smoke is lead, toxic, decontaminate" - here on 18 April. In July, the officials start to react only because the scandal grows. This is exactly how the French citizens know their government will behave.

Again, this is no evidence presented that distinguishes coverup from normal bureaucratic incompetence, and evidence is required in order to make as assertion of the former. The latter, I think, is a given (only being a matter of degree in different bureaucracies)

[John Cuthber]

Lead is hardly the only possible contaminant which would have people wearing masks etc.

Have we ruled out asbestos, for example?
 

6 hours ago, Enthalpy said:

Many people told quickly "yellow smoke is lead, toxic, decontaminate"

By whom?

[Enthalpy]

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.

Frédéric Épaud is a researcher who specializes in medieval wood frameworks. He published his view about rebuilding Notre-Dame's roof structure of oak beams there:
lejournal.cnrs.fr (in French)
in brief English:

• Medieval carpenters obtained one beam per timber, at the centre. No need for giant oaks.
• Narrower oaks dry faster, and carpenters processed them undried.
• 1000 oaks are little. Less than for building a copy of the ship L'Hermione.
• The know-how exists, not only from L'Hermione: the castle of Guénelon is being finished.
• Plans of the roof exist.

This thesis, from an expert, changes the possibilities. The interrogations I still have:

• Processing the timber into beams may happen early, but how long must the beams then dry before assembly? Carpenters use lighter wood presently, of smaller section in sapwood, that starts drying well before they order the beams.
• A metal roof is easily built in 2 years. Drying and hand-working oak takes decades. Shall we wait more than 5 years?
• It wouldn't be the original roof. Is a present-day copy better than a new roof design?
• Wood burns! The lead cover is excluded. Why reconstruct identically a part that nobody sees?
• A titanium or aluminium roof is eternal. Half of the original roof lasted for 800 years, the other half failed.
• The know-how for long-lasting oak frameworks may be lost. L'Hermione and Guénelon are very young.

[Enthalpy]

==========

Please imagine a separation ========== before the paragraph "Frédéric Épaud".

[John Cuthber]

2 hours ago, Enthalpy said:

If 0.3t cyanide had been injected in the atmosphere of a dense city, more people would worry about it.

The population of Paris is about 2 million

And, if they are typical French people, they smoke an average of about 1100 cigarettes per year.
https://en.wikipedia.org/wiki/List_of_countries_by_cigarette_consumption_per_capita

So that's roughly two billion cigarettes per year.

Each cig is about 0.65 g

So that's a total of 1250 tonnes of tobacco.
And, according to this
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4518591/

the yield of cyanide is about 500 micrograms per gram i.e. about 1 in 2000 of the mass.

So that gives very roughly 0.6 tonnes of cyanide released in Paris each year just from cigarettes- there are, of course, other sources too.

"we estimate that 654 tonnes of HCN were emitted in 2012 from LDV in Canada, including ~252 tonnes in Ontario."

from
https://core.ac.uk/download/pdf/82009669.pdf

How worried are people?
Well, not very worried, because the atmosphere is big.

On a related note, how much of the timber had been treated with copper chrome arsenate?

What's the yield of benzo alpha pyrene from timber in fires?

 

[Enthalpy]

Treated timber: good reason to build a roof of metal instead.

Lead oxide doesn't dilute in the atmosphere. It falls down.

On 7/21/2019 at 1:07 PM, John Cuthber said:

OK, so people seem to be saying that because the lead fell down and polluted the floor, it went up and polluted the sky.

 

On 7/21/2019 at 2:35 PM, dimreepr said:

A conspiracy theory? I thought better of you... 

 

On 7/19/2019 at 6:46 PM, swansont said:

Robots use could be because of physical danger from e.g. falling debris.   

Everything I wrote is confirmed in the Press meanwhile, you know? Too late to propose alternative facts.

[swansont]

17 minutes ago, Enthalpy said:

Everything I wrote is confirmed in the Press meanwhile, you know? Too late to propose alternative facts.

A coverup was claimed in the media ("following a media report claiming the extent of lead contamination has been covered up") , but no evidence was presented in the (English) links. So it's a claim. You didn't present evidence, yet you portray it as a fact.

Chernobyl was not mentioned. That's your own hyperbole.

 

[John Cuthber]

2 hours ago, Enthalpy said:

Everything I wrote is confirmed

So who wrote this?
 

6 hours ago, Enthalpy said:

If 0.3t cyanide had been injected in the atmosphere of a dense city, more people would worry about it.

 

2 hours ago, Enthalpy said:

Lead oxide doesn't dilute in the atmosphere. It falls down.

Delighted to hear it. I know Parisians can be a bit odd, but eating from the floor isn't common there.

[Enthalpy]

A governmental health agency published a report on 19 July, including on page 30 a map made by the police of the lead deposits
www.iledefrance.ars.sante.fr (20MB)
it's frightening. The units are really µg/m² and up to 1.3g/m² lead deposited.

I didn't find in the report when the measurements were made. I believe it was in July, after several rains had cleaned the surfaces.

The figures tell how much lead gets dissolved by HCl under conditions that simulate the digestion, which I believe is a small fraction of PbO. Though, at least Wiki tells "Inhalation is a major source"
fr.wikipedia
so the poisoning of people present during the fire may be much worse.

Multiplying the area by the surface density, I get only 1kg deposited right around the cathedral and 2kg on two districts downwind. Though, intuition shouts that the big dense yellow smoke that escaped for hours contained much more PbO. The figures don't add up. Probably most lead oxide deposited farther downstream: excess lead was observed in the air outside Paris. And most lead went to the sewage before the measurements.

To illustrate 1g/m², I weighed dust after cleaning a room: 1.9g over 30m² is yuk, and this isn't poison. At the cathedral, they got nearly that amount on 1m². Pictures appended.

How unhealthy? Imagine that away from Notre-Dame, at Saint-Michel square that kept open and uncleaned, someone wanting to make photos lays his 0.02m² croque-monsieur on the foutain's rim, then eats it. 30mg/m² were measured (but when?), so he ingests 600µg of digestible lead equivalent. If he's an adult with 6L blood, his concentration climbs to 10 µg/dl, the upper limit set by the Center for Disease Control. On the cathedral's square, concentrations were 20* higher.

The concentration may have been much higher right after the fire, and poisoning over the lungs worse.

[swansont]

13 hours ago, Enthalpy said:

A governmental health agency published a report on 19 July, including on page 30 a map made by the police of the lead deposits
www.iledefrance.ars.sante.fr (20MB)
it's frightening. The units are really µg/m² and up to 1.3g/m² lead deposited.

I didn't find in the report when the measurements were made. I believe it was in July, after several rains had cleaned the surfaces.

I would be very surprised if a government report were published less than ~3 weeks after the measurements were made. You have to write the report, edit it, and very likely have to get multiple layers of approval to publish.

 

What is the density of dust, vs density of lead?

[John Cuthber]

On 7/21/2019 at 9:58 AM, Enthalpy said:

Many people told quickly "yellow smoke is lead, toxic, decontaminate"

Unless, of course, it isn't.
Have you seen the pictures of the Amazon forest fires.

Lots of yellow smoke, but I don't see any obvious source of lead.