(I've taken the liberty of un-capitalizing the chemical names -which doth grate - and italicized the reference to inaccurate press coverage!)
On 7 September, Senior Coroner, Richard Travers, announced his findings into the sad death of Zane Gbangbola who died at his home in Chertsey during flooding in February 2014
This followed a five week Inquest which took place in June and July this year.
The finding was accidental death caused by carbon monoxide poisoning from a petrol driven pump used by the family in their home to remove flood water from the basement.
The Council always maintained that there was no evidence of a link between this tragedy and the former landfill close to the family home. It also consistently stated that there was no wider risk to the public.
The Coroner confirmed that he was satisfied that hydrogen cyanide toxicity played no part in Zane's death and that there was no evidence of hydrogen cyanide in the land and lake, concluding that there was no hydrogen cyanide present in the house at the time of the incident. It is hoped that this finding in particular will provide reassurance and confidence to nearby residents who may have been alarmed by some of the inaccurate press coverage made prior to the Inquest.
Spelthorne Council participated in the Inquest from the outset. It co-operated and assisted the Coroner by providing a comprehensive study on the historic land use of the area in question and by commissioning independent experts in the field of contaminated land.
The Council acknowledges that this has been a long and harrowing process for Zane's parents and continues to offer its condolences to the family.
Newsflash: 13:20 Wed 7th September 2016: Coroner Richard Travers' conclusion:
Common sense at last! We've waited more than 2 years for commonsense to prevail. Thank you Richard Travers. I raise my hat to you!
Update: 09:00 Wed 7th September 2016
Coroner Richard Traver's verdict expected in an hour's time, though you have to look hard in the search engines or even the parent's own website to find that information.
Here's where the news of the imminent verdict is to be found:
Or here's a link to the same article in the "Surrey Comet" that's just popped up in my listings for the last 24hrs, probably the original source.
I raise my hat to journalist Rachel Dickerson for a rare instance of responsible "Zane" reporting, one that does not hype up the hydrogen cyanide theory, or as this blogger prefers to call it, total make believe! (The emergency services, environmental agencies really had no busines releasing their crude readings off hand-held meters for a gas/vapour that prefers to remain dissolved in water. The alleged readings in air ("24,000ppm") were frankly ludicrous.). Let's now wait and see if the coroner shares my conclusions.
It's now 10:20, and no news as yet. But the GetSurrey site has come on stream again, promising to keep us informed. It did a briliant job, reporting almost on a daily basis the proceedings of the inquest spread over some 6 weeks. Shame about the two days with no reports, and no clue either as to why there were no reports. Staffing problem? Or something more sinister (evidence heard in camera?).
(Earlier) Update: 13th June 2016
The inquest finally opened today, with two reports so far on the first day's proceedings, one from the Guardian:
This science blogger will be commenting on the scientific aspects from time to time.
His first impressions are hardly favourable, hearing the coroner say that the main focus will be on whether the toxic agent was hydrogen cyanide or carbon monoxide. Why no mention of hydrogen sulphide, H2S, (see this posting) if only to rule it out? Why only HCN and CO, given that there's an industrial estate close to the house and even closer to the previous gravel pit, now a lake? He's also somewhat surprised that the parents were not disabused of HCN being the likely agent, based on its physical and chemical properties (again, see this posting) which makes it well nigh impossible for it to be released from water, flood water included. It's simply far too soluble. As for those reports that a level of 25,000 ppm HCN were detected by first responders (some say the fire brigade, others Environmental Agency staff), words fail me. It would be impossible to have those levels from a pollution incident, short of dropping pellets of solid 100% potassium cyanide into a bucket of acid.
UPDATE: Tuesday 14th June
So far, it's the Guardian that seems to be providing the most informative accounts of what is being said at the inquest. Here's a link to today's proceedings.
Here are the opening words (black font):
The mother of a seven-year-old boy who is believed to have died after breathing toxic fumes at their home in Surrey during severe flooding was warned not to return to the property because cyanide gas had been found, an inquest has heard.
Just hours after Zane Gbangbola was pronounced dead in hospital, his mother, Nicole Lawler, was informed by medics that the “Health Protection Agency had identified small pockets of hydrogen cyanide at the home”, she read aloud from her medical notes.
She told the inquest into Zane’s death, a doctor had told her she was not allowed home, and continued reading aloud the entry: “We need to ensure that the patient does not return to her home.”
One can but hope that the technology used to identify those "small pockets" of cyanide gas will be thoroughly examined. See my initial views expressed back in Feb 2014 in the immediate aftermath of the tragedy. Personally, I doubt whether there really was cyanide gas in that house. A reading for "cyanide" on a meter is not conclusive evidence for the presence of cyanide, especially if dual purpose and improperly calibrated. It could have been carbon monoxide registering as cyanide or possibly other toxic gas(es).
See also today's BBC report.
"Small pockets"? Might we be seeing an attempt to back-track on that claim for cyanide? Might we see further attempts to salami-slice it away in the coming days and weeks? Why don't they stop wasting everyone's time, the coroner's court included, and admit they got it wrong, setting too much store by the digital readout on a meter designed as a precautionary 'sniffer' in smoke-filled buildings, to warn firemen of POSSIBLE cyanide hazards, not a mobile forensic laboratory?
Why the silence from the Royal Society of Chemistry and/or other learned societies? Why have they allowed those headlines on "leaking cyanide gas" to go unchallenged, allowing headline writers to dictate the agenda and indeed entire debate, the initial proceedings of coroners' court included.?
Update: Thursday 16th June
Here's a couple of key sources re hydrogen cyanide "gas" (though as the first makes clear, it really ought to be called hydrogen cyanide vapour (unless one is given to talking about water gas in the air around us, instead of water vapour.
(Science bit: all vapours are gases, but not all gases are vapours, it depending on the physical state of the substance in question at normal temperature and pressure (NTP). Water is a liquid at NTP (boiling point 100 degrees C) , and so is hydrogen cyanide (BPt 26 degrees C) so both should be referred to as vapours when referring to their gaseous states It's maybe those "gas chambers" once used for execution in the US that have given rise to the incorrect term "hydrogen cyanide gas".
The second reference refers to decontamination procedures involoving hydrogen cyanide vapour (yes, "vapor", US spelling) that involves spraying with water to "knock down" the vapour, alluding to the unlimited solubility of HCN in water (it's miscible in all proportions), so that it's virtually impossible for flood water, no matter how contaminated (improbably some might think) it might have become with HCN, to release HCN vapour into the air except in tiny amounts).
Update: Saturday 18th June
The "Get Surrey" online newspaper is providing "live" commentaries on what is being said each day, each hour at the inquest. Yesterday's report (Day 4) is available on this link.
Thanks 'Get Surrey' for providing this valuable service. An email saying as much has been sent to the Editor.
This blogger is of course reading the exchanges on who said what to whom in the hire shop (re petrol-powered pump especially) with interest, and wondering what's suddenly taken the focus off the "landfill cyanide gas" theory, or as I would say misconception, but I do not intend commenting here on anything except the scientific aspects. What a pity the MSM cannot take the trouble to gen up on the chemical detail, or when it does (as happened recently when I had emails and phone calls from a national Sunday) chooses to ignore the hard relevant facts, focusing instead on the alleged cover up claims, denial of legal aid for inquest etc etc. My opinion of our country's MSM continues its daily free-fall descent (noting in passing that the Daily Telegraph has expunged all readers' comments from its new format, while its journo columnists continue to talk down to us from a great height, telling us what we should all be thinking). Our so-called democracy has become a sick joke.
Update 21st June
Here's a verbatim quote from Zane's father, Kye Gbangbola, giving testimony at yesterday's inquest proceedings (Day 5, Get Surrey site):
The key words are "rhabdomyolysis" and "hydrogen cyanide":
The inquest heard that around 24 hours after being admitted to the hospital, Kye had “no ability to use [his] legs”.
“I think I would've started losing my legs into the evening of the night before,” he told the inquest.
“I've been told it's declined even more from the tests since, but tests weren't done immediately.
"I also had some very serious temperature issues...there's lots of things which is why I tried to make it as clear as possible in the health report.”
Asked whether a clinician had sought to give him a diagnosis, Kye said he had received one in August 2014, when he was told he had Rhabdomyolysis – a condition caused by hydrogen cyanide poisoning.
A quick search on Google suggests that hydrogen cyanide is just one of a multitude of causes of rhabdomyolysis (essentially an excessive rate of muscle breakdown that can overload the kidney with myoglobin - the latter being the muscle's equivalent of blood haemoglobin - oxygen-binding pigments in both instances). Guess what else can have the same effect as cyanide? Yes - carbon monoxide and hydrogen sulphide .
Here's the relevant passage from the above pdf:
"Carbon monoxide can cause a functional anemia that impedes oxygen delivery to tissues . Carbon monoxide also impairs adenosine triphosphate production, causing a direct effect on myocyte energy production. Other agents such as cyanide and hydrogen sulfide can inhibit electron transport and disrupt adenosine triphosphate production."
So, muscle breakdown is NOT a specific indicator for hydrogen cyanide toxicity. Any chemical agent tbat destabilises the haemoprotein myoglobin can produce the condition. We await further evidence for a specific role for HCN, as distinct from CO or H2S.
Equipment used to detect gases:
Quote from GetSurrey report:
"Bruce Joliffe from Bureau Veritas is now giving evidence in court. Mr Gbangbola will continue to give evidence later.
The court is being told that Mr Joliffe prepared a report February 12 2015 as part of his role as a senior consultant and scientific adviser at Bureau Veritas. He said one part of the company is to give scientific advice to fire services. His report looked at performance and results for equipment used at the property by the fire service.
He said the equipment is designed to look for different substances. Mr Joliffe said he was asked by police to examine the possibility for any gases that would have caused the alarm to activate. He said apart from hydrogen cyanide, which the equipment is designed to detect, it could pick up nitric oxide and nitrogen dioxide. He said they “could trigger a response but not within its calibration”.
He said to determine which substance had triggered the alarm, he said they would recommend a second test, with different equipment."
Yes, but we need to know if there's any way that the equipment could have detected and registered an alarm or false digital readout for carbon monoxide, hydrogen sulphide or other prime candidates for poisoning by toxic landfill or other gases, in addition to the two aforementioned (nitric oxide and nitrogen dioxide). The latter are hardly suspects in the present circumstances, being more associated with exhaust emissions from diesel rather than petrol engines (due to operating at higher temperature/compression).
Readings "not backed up"
The court heard tests were conducted at Hammersmith Fire Station to look at what effect exhaust gases would have on the readings. Tests were done on exhaust from diesel, petrol and modern petrol electrical generator.
He said in conclusion to the tests, the gases that most most probably caused the sensor to activate, were the oxides of nitrogen.
Mr Joliffe said:
Any detection that happens on one piece of equipment to be backed up on another piece of equipment. That didn’t happen. If it’s not backed up we can’t categorically say that something was present.Seems the limitations of the equipment are finally being recognized (see my original suspicions below expressed back in Feb 2014, especially when that figure of 25,000ppm HCN began to appear in the media, which was clearly a nonsense).
"Detection of hydrogen cyanide"The court has heard the equipment was designed to detect carbon monoxide, ammonia, hydrogen sulphide, hydrogen cyanide and chlorine.
Leslie Thomas QC is asking Mr Joliffe if there was any detection of carbon monoxide from the home, to which he said there was not.
Mr Joliffe said he was contacted by Surrey Fire & Rescue service at 6.05am on February 8 by pager, and was told response there was a reading for hydrogen cyanide of 2.5 parts per million and had used dregar tubes to back it up, “apparently confirmed by them” although there was an “inconclusive colour change”.
Asked by Mr Leslie about if there was any mention from Surrey Fire & Rescue of detection of carbon monoxide, to which he said there was not.
Of all the sweeps there was not one reading of carbon monoxide, correct?Mr Joliffe agreed.
Two important things there: (1) no carbon monoxide (but can that be believed, given the equipment is acknowledged to be far from specific as to what it is claimed to detect?)
(2) No, it's not 25,000 ppm hydrogen cyanide, that totally absurd figure that's been bandied around in the media, with no one bothering to check its accuracy, but instead a mere 2.5 ppm - ten thousand times smaller!
Mr Joliffe's evidence continuesMr Thomas is looking at a statement from Natasha Farinha, an environment officer for the Environment Agency.
The statement refers to a reading of hydrogen cyanide and ‘other lower readings’. Mr Thomas asked Mr Joliffe if he was informed about other readings, to which he said “no that’s not what was told to me”.
The statement added that a water sample taken showed a reading of 2,400 parts per million for hydrogen cyanide, taken in the evening.
Mr Thomas said:
Maybe there’s some confusion in the recording of the reading. You were told about hydrogen cyanide reading early in the morning. Did any one tell you that another reading was taken later in the day?Mr Joliffe answered no. He added if these readings mentioned in the statement were hydrogen cyanide he would have expected to have been told about it.
Now we're being given a reading for the flood water, rather than air above it, and it.s neither 2.5ppm nor 25,000 ppm but 2,400ppm. This is starting to look incredibly amateurish. But then the equipment given to firemen (for use in fires!) is not a portable chemistry laboratory. Having said that, an over-reaction is understandable when one goes to a house in the middle of the night and finds parents and son ill or unconscious.
Here's a link to the Guardian's summary of the Day 6 proceedings.
All the above has been written in 'real time', usually within an hour or at most two of the GetSurrey update. That won't be possible tomorrow due to other commitments, but I'll endeavour to put up my own 'take' early evening tomorrow. So far, most of my initial hunches have proved correct, notably that there's no strong evidence for the toxin being hydrogen cyanide, and that the alleged 25,000ppm level is a figment of someone's imagination, or a misplacing of the decimal point 4 places to the right!
Interestingly, this blog posting has suddenly returned to listings under a simple (zane gbangbola) Google search, approx Page 4/5. It's good to see that premier search engine is on the ball (would that were always the case!).
Have just spotted this Guardian report from Day 6 labelled "3 hours ago" and thus "new" with a lot of additional detail missing from the GetSurrey report: It also has somewhat misleaduing information re hydrogen cyanide v carbon monoxide: my bolding.
Jolliffe said two other gases could also trigger the hydrogen cyanide alarm in the microtector and could have activated the alarm in this case – nitric oxide and nitrogen dioxide. In his report, he concluded that both gases and carbon monoxide would be present in exhaust fumes from a petrol pump.
Thomas asked him if any carbon monoxide had been detected at the scene: “Of all the sweeps there was not one reading of carbon monoxide, correct?”
Thomas said that if the fumes were from the petrol pump, there should be seven or eight times more carbon monoxide than nitrogen oxides detected, “and not a scrap of it was detected”.
“Doesn’t that lead you to believe that wasn’t a false reading, but was hydrogen cyanide?” Thomas asked Jolliffe.
“No,” Jolliffe replied. The testing was conducted several hours after Zane’s death, and more buoyant gases such as carbon monoxide “would have left the house swiftly”, he said.
Wrong. Hydrogen cyanide and carbon monoxide have virtually the same molar masses (27 and 28 respectively) and thus essentially the same vapour densities of half the molar mass, i.e. 13.5 and 14 respectively) and thus the same "buoyancy". But these figures are very close to those of the nitrogen and oxygen in air, with vapour densities of 14 and 16 respectively, so there's no buoyancy difference worth speaking of between the 4 gases, and such little as there is would be largely nullified by the tendency of the gases to diffuse fairly rapidly causing rapid mixing.
Personal view: Mr. Jolliffe should state who made the gas sensor, its product code and a link to its full specifications, sensitivity limits and limitations. I strongly suspect that these multi-meters are nothing like as specific as they are claimed to be, given they operate on largely empirical electrochemical principles with sensing electrodes that are less than perfect in distinguishing between one gas and another.
Update from Day 7 of inquest (22nd June)
Here are two limks to the proceedings, both from the GetSurrey site:
First, the live updates:
Second, a summary of the above (with additional information).
There is insufficient hard scientific information in either to make comment on my part worthwhile. One thing seems clear, as stated earlier: the handheld meters that claim to measure this or that chemical contaminant are frankly more marketing hype than genuine analytical instruments.
23rd June 2016 (am): Day 8 of the inquest: more to follow, assuming that EU Referendum day does not prevent "business as usual".
23rd June (late pm): How odd! After 7 days of continuous live reporting from the inquest, the otherwise commendable GetSurrey site has abandoned us without a word of explanation. Nope, there's no Day 8 report, and no reason given for having 'gone off air'.
24th June (am): The GetSurrey site has resumed reporting of the inquest. Here's a link to what is now Day 9 with live updates. Curiously there's no mention far less explanation for the absence of a Day 8 report (with expected testimony from a sizeable number of hospital staff according to the tail end of the Day 7 report). Maybe it was dealing with sensitive autopsy information, and was kept out of the public domain out of consideration for the parents. OK, that I understand, but that information needs to be available to those of us who have a legitimate interest, in this instance biomedical/scientific in what happened that night, given the claims of negligence/cover up, given the anxiety that has been created for the Gbangbola's neighbours who have been told they live next to a "toxic" landfill site.
I am now thinking seriously about writing to Mr.Richard Travers, the coroner, explaining that this is probably the one and only internet sites hosted by a retired biomedical scientist attempting to understand the real reasons for the tragedy, and one that makes the greatest effort to establish and report the objective facts. Might it be possible to see a transcript of the Day 8 proceedings? Time will tell. In the meantime I will have to be extra careful with my reporting, given my ignorance of the Day 8 testimony.
Update Saturday June 25, 2016
This blogger was about to provide a critical summary of Day 9, but decided first to do a quick check on Google, just to make sure that this posting was still visible on a search under (zane gbangbola). When last checked a couple of days ago it was on Page 4 or 5 of returns (the positiion can vary from day to day, sometimes hour to hour).
I'm sorry to say the Google is up to its old tricks again, suppressing the citizen blogger. This time it's done it by the simple expedient of showing the first 52 returns only.
|Sat 25th June am: Google returns for (zane gbangbola) stop at the 52nd on Page 6. This site has essentially been de-listed, or for all I know, blacklisted.|
It only takes a new crop of MSM reports, all reporting the same news item, e.g. Day 7 or Day 9 of the inquest for non-MSM sites like this one to pushed down in the rankings, and disappear altogether if there's then an arbitrary stop placed as here (52 returns only).
Old saying: if one's not on Google, on might as well not exist.. There will be no more reporting from this 'de-listed' blogger. I'm now considering a letter to my MP, protesting at the description of Google as a "search engine". There's far too much opportunity for human intervention by one or more of its 53,000+ employees, aka 'curating' of returns (selection, filtration, blocking etc) for that term "engine" to be justified.
Here's my original posting .
Yes, there's a story in today's Mail on Sunday that is not only tragic, but incredible - in more ways that one.
Here's a screen grab of the article.
Yes, it seems totally incredible (though by no means impossible) that the threat to life of living in a flood-prone area - in this case close to a river- should come from toxic gas.
That much is possible when you read that the property was situated over an old landfill fill site, something that happens with increasing frequency thanks to dereliction of duty by those who are charged with protecting public safety.
But in this instance the chemical details simply do not ring true to this retired biomedical science bod . The official line is that it was hydrogen cyanide (HCN) that killed the wee lad, AND left his father a permanently paralysed paraplegic.
Without further ado, I'll say straightaway that HCN does not fit the facts, physically, chemically, biochemically and microbiologically. Nor does carbon monoxide (also proposed/considered) quite fit with the particular circumstances. It was far more likely to be have been HYDROGEN SULPHIDE, H2S.
I'll be back later with my reasons for saying that. Believe me, there are any number of precedents for suspecting that it was H2S that was the silent killer. What, plain old H2S do I hear you say, the smelly component of bad eggs, farts, schoolboy stink bombs? Yes. Plain old H2S, which as the old chemistry textbooks used to delight in pointing out, is more toxic, weight for weight, than hydrogen cyanide!
What's more, as those same fact-laden books in my public library, way back in the 50s, grimly pointed out, the earliest effect of "smelly" H2S is to knock out the olfactory system, i.e. sense of smell.
The likely mechanism of H2S production? Anaerobic fermentation of sulphur-containing waste, notably waste foods with proteins. The same process takes place in our own large intestine, especially if there's been malabsorption in the small intestine due to bowel irritability.
The MOS is up to its usual tricks, inviting readers to be first to place a comment in the box provided.
What they don't tell you is that it could be HOURS (I kid thee not) before those comments appear, and since they are then listed chronologically, most recent ones first, the folk who responded early invariably find their comment entombed at the bottom of the stack. The UK's MSM journos with very few exceptions ignore what appears after their articles 'under-the-line', which is why this science blogger stopped bothering to post comments a long time ago. In any case our journos - liberal arts graduates for the most part- detest citizen-commentators with specialist knowledge. They can't get their minds around that - namely that some well-informed folk are not sitting in Universities waiting for the phone to ring, praying for Fleet Street to check on its facts that rarely happens these days - journos much preferring to publish what's immediately to hand, right under their noses- - and not bothering to monitor subsequent responses re veracity or otherwise, far less issue corrections. (It took a whole month once for a Sunday newspaper to correct its claim that carbon monoxide gas is lighter than air, and so quickly moves from faulty boilers to concentrate in the upper floors of a house. How do I know? Because I was the one who wrote and pointed out the error).
This septic (science-averse) isle!
I'm also increasingly contemptuous of Google as a search engine. Time and again I enter 3 or 4 carefully chosen keywords, only to find that the returns ignore one or more, and even SCORE THEM THROUGH as if to say "silly boy, you are looking for something that is far too specialized to be of general interest". Yes, I know about placing quotation marks around key terms, or prefacing with a + sign, but that made not the slightest difference a few minutes ago. As for Google's repeated attempts to give returns on similar but non-identical words, then coyly asking if one really meant one's own word - I am now seriously taking a fresh look at the alternative search engines, even ones with silly names, once convinced they are not re-packaged Google returns.
The story I'm looking for concerns a worker at a centre for collecting spent batteries, whether for recycling or safe disposal I'm not sure, who sorted out the silver-containing batteries and rigged up (unofficially as I recall) an acid bath , hoping to dissolve out and recover the silver. What he didn't know (I'm hazy myself re the details) is that those batteries can and do give off hydrogen sulphide when placed in acid. The man was found unconscious, close to death, and like Zane's poor father ended up as a paraplegic, but also with serious mental impairment too as I recall.
Admittedly the story is old, since it was featured in a chemistry teaching aide I used in the 90s (having once done a spell as a science schoolteacher thanks to Thatcherite butchery of industrial research associations). Each double page was given over to a facsimile newspaper clipping (so that particular H2S-poisoning incident might have occurred in the 80s or even earlier).
Returning to Google: at least this posting has been instantly hoovered up by Google's web crawler - provided you enter search terms that are sufficiently specific:
Still Sunday: 08:44
Might there be parallels with Cameroon's Lake Nyos disaster in 1986 that killed hundreds of people, and most of the livestock?
The deaths are usually attributed to a giant bubble, dare on say burp, of CO2 gas from the depths of the volcanic lake, and CO2 as we know is a heavy suffocating gas, at least before it's had time to disperse and become irreversibly mixed with the atmosphere by gaseous diffusion (see my Most Popular posting - top of sidebar listing). But one can find plenty of references to "sulphur" (as in the link to the BBC's original report above) or more informatively "hydrogen sulphide" as having contributed at least in part to the rapid onset of collapse and unconsciousness. Eye witness, correction, nose-witness reports, if one can refer to them as such, attested to the presence of an all -pervading aroma of rotten eggs.
Still Sunday 09:00
Have just tried a new Google search to see if I can filter off returns that have "cyanide", and which look for "sulphide". So I left "hydrogen" off to avoid ambiguity. Here's what comes back:
The yellow rectangles are mine. I have asked Google to search for "sulphide", and what does it do? It scores out my "sulphide" and proceeds to list returns that make no reference to sulphide. Maybe my posting is to be found later, but that's hardly the point. If it's there, as one now expects, having seen it earlier, then it should have been at the top of the list oif, as I suspect, it's the only one to specifically mention "sulphide".
What Google is doing here is totally reprehensible, at least from a scholarly perspective, in that it is demoting new postings, simply on the grounds for containing novel terminology.Yet it's that same novel terminology that is what's new, but relying on search engines in particular to get some visibility.
I shall now go back to the Mail article, to see if any comments have appeared.
It's now 09:16, and still there are no comments displayed. Maybe none submitted? Possibly, but here's the date and time stamp from the top of the article against the journos' bylines (Note what else comes with the cut-and-paste which normally I delete, but will keep on this occasion in the hope that it triggers some kind of system at the Mail to see what others are saying out here in the cold dark vacuum of the citizen blogosphere.
At last: 21 comments have now appeared en bloc beneath the article, the first posted 10 hours ago, no less.
From having a quick read, one should not be too quick too discount carbon monoxide from a flood pump, despite attempts to exclude that as a source of fumes. I shall keep an open mind, knowing how slow some medics and hospitals are and have been to diagnose CO poisoning, at least in its early stages when folk are complaining of headaches and nausea. (And we all know how quick hoteliers the world over are to blame CO poisoning on food poisoning from street stalls etc!). However, if a child DIES from suspected gassing, then the tests for post mortem CO are robust enough to show up hours or even days later. Are they aware of the acute toxicity of H2S, encountered only rarely? Do they have specific and routine screening tests > I doubt it. My money is still on H2S, not HCN, not CO or CO2.
Why do I think hydrogen cyanide to be a non-starter? First, I'm not sure that a first-on-the-scene firefighter with an HCN-detector kit (used to warn of hazards from flammable sofas etc) should be the last word on the matter (see article).
Secondly, more importantly, HCN shows "extreme solubility" in water (which must include flood waters). I shall try to get an exact figure, but for now and entirely confident that hydrogen cyanide could not be evolved in sufficient quantities from flood- inundated subsoil to become a lethal hazard.
Hydrogen sulphide? Much, much less soluble in water. I'll try looking out some figures. First, grandchildren await.
11:35: Answer: approx 4.5 grams of H2S per litre/kg of water. Thus the reason for describing H2S as being only slightly soluble in water. One can confidently expect to see it bubbling up through water from a subterranean source, e.g. rotting organic matter. That would NEVER be the case with HCN - it being far too soluble for bubbles to survive long enough to make it to the surface. I shall try to get an exact figure on the (super) solubility of HCN.
11:45: No wonder I couldn't find a figure. The solubility of HCN is described in this link as INFINITE at all temperatures. In other words, there is no upper limit. HCN could not possibily be a hazard in the vicinity of waterlogged subsoil. Most would stay in solution.
Sources of pollutant HCN? Hardly likely as products of anaerobic fermentation, given that HCN is toxic to most microorganisms, not just fish, mammals etc. HCN binds to cytochromes that are ubiquitous in the cells of living organisms. H2S on the other hand is a well known byproduct of anaerobic microbial metabolism.
It looks like it's a two-way contest between H2S from fermenting landfill and CO from an oxygen-starved petrol-driven pump. Which of those was more likely?
12:05: The comment count on the Mail article is still 21, as earlier at 09:40. Doubtless, that will mean another tranche of comments are being held up, awaiting "moderation", which all too often means vetting by the style police whose knowledge of the world and its technicalities must remain a matter of speculation.. As I say, I stopped posting comments to these overbearing MSM sites a long time ago.
15:45 Here's some quantitative data on what happens with increasing concentrations of inspired H2S:
Parts H2S per million parts of air - Effects
0.13 ppm - This is the odour threshold. Odour is unpleasant. Sore eyes.
4.6 ppm - Strong intense odour, but tolerable. Prolonged exposure may deaden the sense of smell.
10-20 ppm - Causes painful eye, nose and throat irritation, headaches, fatigue, irritability, insomnia, gastrointestinal disturbance, loss of appetite, dizziness. Prolonged exposure may cause bronchitis and pneumonia.
30-100 ppm- Sickeningly sweet smell noted.
50 ppm - May cause muscle fatigue, inflammation and dryness of nose, throat and tubes leading to the lungs. Exposure for one hour or more at levels above 50 ppm can cause severe eye tissue damage.
100-150 ppm- Loss of smell, stinging of eyes and throat. Fatal after 8 to 48 hours of continuous exposure.
200-250 ppm - Nervous system depression (headache, dizziness and nausea are symptoms). Prolonged exposure may cause fluid accumulation in the lungs. Fatal in 4 to 8 hours of continuous exposure.
250-600 ppm- Pulmonary edema (lungs fill with fluid, foaming in mouth, chemical damage to lungs).
300 ppm - May cause muscle cramps, low blood pressure and unconsciousness after 20 minutes.
300 to 500 ppm may be fatal in 1 to 4 hours of continuous exposure.
500 ppm - Paralyzes the respiratory system and overcomes victim almost instantaneously. Death after exposure of 30 to 60 minutes.
700 ppm - Paralysis of the nervous system.
1000 ppm - Immediately fatal.
If I'm not mistaken, some of those suicide kits that have been used in enclosed spaces (cars etc), especially in Japan and elsewhere, are H2S based.
16:20: Still the same 21 comments under the Mail article. This time it's not me who is spitting blood, but those who have taken the time and trouble to compose a comment, only to see it held back, not knowing if or when it will appear. Click-bait journalism?
16:40 This screen grab is from an earlier Mail article (9 August 2014) covering the tragic aftermath of the Chertsey flooding:
When the floods came, it wasn't a faulty pump that killed our son... it was deadly cyanide gas: Parents say that leaking landfill site real cause of death - and there's a cover-up
- Zane Gbangbola died during heaviest floods in UK for 248 years in February
- Allegedly killed by faulty pump at riverside home in Chertsey, Surrey
- New evidence suggests carbon monoxide seeped from petrol-driven pump
- Substance has left his father Kye paralysed from the waist down
- Grief-stricken parents fear cover-up as they 'had not used the pump'
- Scientists say 'gas used in Nazi camps could come from nearby landfill site'
The importance of calibrating against known concentrations of each gas is stressed to ensure accuracy (and avoid cross- reactions?). How reliable were those detectors on the night in question in alerting to the presence of cyanide specifically, in a situation where the culprit gas may have been carbon monoxide?
Thoughts are now crystallizing. Firemen carry around these gizmos that warn them of dangerous products of combustion - or partial combustion, notably carbon monoxide and, we now learn, hydrogen cyanide.
One can understand the device being used in a burning building. But a flooded home as well, albeit one in which a child has died and his father rescued in the nick of time? Why would a fireman check for gas contamination? Presumably because the obvious cause of unconsciousness and death was from carbon monoxide, especially of petrol-driven pumps were on the premises (whether used or not). But a reading was registered for hydrogen cyanide (it's not clear yet whether one was also made ofr carbon monoxide). Did that really mean HCN was around, or was the detector faulty, especially if the twin type (see above) registering the presence of cyanide as well as, or instead of, carbon monoxide. Is this entire story of gaseosu emissions from landfill site the result of faulty instrumentation?
Remember: these hand-held meters do not measure CO and HCN the way that a chemist would do so in the laboratory, using "wet chemistry" maybe, or more sophisticated methodology that isolates the components by chromatography (usually HPLC) with runs against the authentic standards. They use what are essential electrochemical devices that are secondary rather than primary detectors - where there cannot be 100% certainty that one is really measuring the target substance.It'sthe difference, say, between a mercury thermometer, where one can see the expanding liquid climb up the scale, and a thermocouple where all one can see is a digital readout.
The Turin Shroud, which I believe to be a medieval (14th century) attempt to simulate what an imprint of the crucified Jesus in sweat and blood onto Joseph of Arimathea's linen would look like 13 centuries later. See my specialist Shroud site.