Carbon monoxide in passenger cabin?

[deSitter]

Delta flight diverted to Tulsa after illness reported on Saturday flight - KJRH.com (http://www.kjrh.com/news/local-news/delta-flight-diverted-to-tulsa-after-illness-reported-on-saturday-flight)

It apparently wasn't the fish.

How could this happen? Never heard of such a thing.

[Ian W]

It sounds more like mass hysteria (psychogenic illness What Is Mass Psychogenic Illness? - American Family Physician (http://www.aafp.org/afp/2000/1215/p2655.html) ), with the rate of change of cabin air and the mixing it would be unlikely to be CO. One person feels ill and fills a sick bag and others around are similarly affected.

[CONSO]

TRY AGAIN re carbon Monoxide

TULSA -- Several passengers voiced their frustrations after a flight from Atlanta to Denver was diverted to Tulsa.
Dylan Doyle was on his way from Atlanta to Denver to see his girlfriend, however; the trip was cut short when Delta flight 1817 was forced to land because 9 people were feeling nauseous.
"As people started seeing other people freaking out everybody just kind of went into a panic," said Doyle.

"We arrived, assisted with evaluating 12 patients who had complained of or were showing symptoms of carbon monoxide poisoning," said Tulsa Fire Captain Stan May.

[Hotel Tango]

showing symptoms of carbon monoxide poisoning

Doesn't mean it was cmp though.

[MrsDoubtfire]

From newson6.com:
Tulsa firefighters said the Delta airline passengers who became ill on a flight that was diverted to Tulsa were suffering from elevated carbon monoxide levels in the blood.
....

The district chief that responded to the incident said they initially had reports that 12 to 15 passengers complained of nausea, headache and dizziness, TFD told News On 6. EMSA and Hazmat crews responded and pulled everyone out of the plane.EMSA treated nine people, according to spokesperson Kelli Bruer. The fire department said the patients recovered with fresh air and the administration of oxygen.

Another passenger was transported to the hospital on an unrelated complaint of hypertension, a TFD spokesperson said.

The MD 90 plane was evaluated by Tulsa Hazmat crews who did not find elevated CO levels. The plane was released to Delta maintenance, according to the Assistant Chief's Office. TFD noted that people in the front of the plane did not experience symptoms of illness.


And btw from Avherald:
Accident: Germanwings A319 between Stuttgart and Hamburg on May 11th 2016, two cabin crew poisoned by carbon monoxide
Emergency services, paramedics, arrived and took measurements for carbon monoxide, one of the flight attendants showed a value of 9 (normal values 0-3) prompting the paramedics to immediately call an emergency doctor, who confirmed carbon monoxide poisoning, a second ambulance was called, one paramedics team per flight attendant, with the emergency doctor coordinating efforts to stabilize the patients, carbon monoxide levels in the blood still rising until reaching a value of 13.

[cwatters]

The thing about Carbon Monoxide is that you don't need very much to produce symptoms.

Carbon Monoxide Poisoning. Free information. Patient | Patient (http://patient.info/doctor/carbon-monoxide-poisoning-pro)

Carbon monoxide competes with oxygen to form carboxyhaemoglobin (HbCO) instead of oxyhaemoglobin but it has 210 times the affinity for haemoglobin. In an atmosphere of 21% oxygen and 0.1% carbon monoxide, therefore, the blood will leave the lungs about 50% saturated with oxyhaemoglobin and 50% saturated with carboxyhaemoglobin.

An ambient carbon monoxide level of 100 parts per million (ppm) produces 16% HbCO at equilibrium, which is sufficient to produce clinical symptoms.

[Julio747]

Highly toxic at very low levels. Burn any hydrocarbon without enough oxygen, you will get CO. But it should be outside not inside.

The bright red colour of carboxyhaemoglobin (vs deep red for oxygenated, and blueish for deoxygenated) normally gives it away.

The question is: how might exhaust fumes end up in the cabin?

[lomapaseo]

The question is: how might exhaust fumes end up in the cabin?

might not be from the exhaust

[cwatters]

I tried to google up a previous example but could only find this one on an MD80 from 1989. (Yes I know the MD80 isn't an MD90).

https://news.google.com/newspapers?nid=1310&dat=19890801&id=W_RVAAAAIBAJ&sjid=l-EDAAAAIBAJ&pg=1485,92435&hl=en

[barit1]

A piston engine normally generates CO as a result of a rich-burning mixture. The excess fuel is necessary for cooling the hardware.

A turbine engine conversely is lean burning, because the excess air in the cycle does the cooling. Although a minute amount of CO may be generated, it does not flow upstream through the compressor to the bleed ducts and cabin pressurization.

I'd keep looking.

[Julio747]

I don't see any other sources of CO on a plane apart from the engines and the apu.

And three points. Planes burn a huge amount of carbon per second. So the % CO may be small but the absolute amount is big (compared say with a water heater, known killers).

A jet engine working properly might produce little CO, but what if it had a problem?

And finally, these pax did not die. The level of CO must have been tiny.

So where else to look?

[vapilot2004]

Once airborne, jet exhaust is not going to get into the cabin air system. Even on an engine with a problem, if it is running and producing thrust, the bleed system air is tapped well upstream of the fires and exhaust products of combustion.

On the ground, ingestion of fumes from other aircraft, ground equipment, or when the wind and aircraft orientation is just right, from your own engines or APU exhaust can happen. In any case, the fumes will be highly noticeable by most people, whereas CO has no odor.

It is possible there was something foreign to the aircraft in the cabin or cargo hold that produced the harmful gas. Failing oil seals have been known to affect cabin air, but CO would not be present.

[lomapaseo]

It is possible there was something foreign to the aircraft in the cabin or cargo hold that produced the harmful gas. Failing oil seals have been known to affect cabin air, but CO would not be present


unless ................................

[deSitter]

This was an MD-90 - do those have hush kits? Can hush kits affect how fuel is burned? I have definitely smelled jet fuel fumes on DC-9 series aircraft in the past. Apparently the passengers in the front of the plane were unaffected.

[vapilot2004]

No need on the 90s (or the MD-80 for Stage III).
Only the original old gal could only manage Stage II out of the box.

[Radgirl]

I really would not rely on a Fire Chief for diagnostic skills. Especially one looking for fame, funding and publicity talking to the media. If it was CO poisoning, the hospital would easily measure raised carboxyhaemaglobin levels - simple blood test in a small hospital, putting a probe on a finger in a teaching centre.

Many things cause nausea, headache and dizziness. CO poisoning is rare and in most cases you would smell other contaminants. Anyhow, it appears engineering found no problem.

[hoss183]

This could easily have come from oil contamination from a faulty oil seal in the engine, or faulty AC pack. Its not the first time those failures have occurred.

[Volume]

contrary to other dangerous things in the cabin air, carbon monoxide is included in the certification satndards and measured during the flight testing of the aircraft.
Number one source for CO is recirculated engine exhaust when running on the ground with adverse wind. There should basically be no CO in the engine upstream of the bleed air system. Same with APU, so unless some of the intake/exhaust ducts do leak, it is highly unlikely to have CO in the bleed air in flight.
On the ground it can be a totally different story

Something smoldering somewhere may produce CO, oven insulation, bleed system contamination, electric fire...

[.Scott]

What makes me suspicious of the CO diagnosis is the method of recovery. Normally, the patients would be given oxygen to breath and that would reduce their CO levels by 50% every 80 minutes. Walking around in fresh air (as is reported) reduces CO levels (actually, the COHb level) by 50% every 320 minutes (https://en.wikipedia.org/wiki/Carbon_monoxide_poisoning#Treatment).

I think we need to consider this scenario: Many passengers smoked before boarding the plane - and those smokers had a lower tolerance for the reduced cabin air pressure. Some of these passengers and perhaps some others got sick during the flight so the flight landed. On landing, many of the sick passengers had elevated CO levels from smoking - but not elevated so much that the were offered oxygen therapy.

Regarding CO levels: Home detectors can detect 1 or 2 parts per million (ppm), flu-like symptoms start at 35 ppm, loss of judgement starts at 200 ppm, convulsions within 45 minutes at 800 ppm, death in less than 2 hours at 1600 ppm.

During a power outage in my town that lasted several days, I was with a volunteer group that worked with the Fire Department. We went home to home checking on the use of generators. Improperly positioned generators resulted in levels of 35 and 50 ppm at two homes. In both of those cases, fumes could be easily smelled. No symptoms were reported.

... or, there was CO on the plane and the low cabin pressure aggravated the effects of the CO poisoning.

[Huck]

What makes me suspicious of the CO diagnosis is the method of recovery. Normally, the patients would be given oxygen to breath and that would reduce their CO levels by 50% every 80 minutes. Walking around in fresh air (as is reported) reduces CO levels (actually, the COHb level) by 50% every 320 minutes (https://en.wikipedia.org/wiki/Carbon...ning#Treatment).


My father started with Northwest Orient in 1968.

He told me a tale: in the old days, a crew flew overseas, and then rode in an ancient vehicle to the hotel. The vehicle had an exhaust leak in the passenger compartment.

Everyone decided to go out and drink except the captain. He went upstairs and went to bed. The captain died from carbon monoxide poisoning. The rest of the crew stayed up long enough to safely get the CO out of their system.

The moral of the story: you have to go at least get one drink when you arrive at the hotel. You never know if you've been poisoned.....

[hoss183]

... or, there was CO on the plane and the low cabin pressure aggravated the effects of the CO poisoning.

good point. The quoted ppm levels of CO above are all for atmospheric pressure. One would need data of the partial pressure effect of CO at altitude.
e.g. Oxygen is perfectly healthy for us at atmospheric pressure, but breath it whilst diving and it becomes toxic at a certain depth corresponding to the partial pressure rising above a certain value.

[Radgirl]

CO poisoning can be related to partial pressure. The partial pressure is independant of atmospheric pressure or altitude, but as cabin pressure falls to say 8000 ft the effect of a set percentage of CO in the cabin will fall as the pp falls.

This is separate from the effects on oxygen delivery. CO displaces oxygen from haemaglobin. The partial pressure of oxygen in the blood falls with decompression so the effect of CO on oxygen delivery vs oxygen requirements will be magnified in respect of the tissues.

So yes you may get increased headache with altitude but conversely you should become symptom free more rapidly when back on the ground

Smokers will already have some CO on board from their cigarette so theoretically need less additional CO to produce symptoms

Of course all hypothetical as no CO demonstrated in any passenger nor any fault in the aircraft. But the Fire Chief had his moment of fame and possibly will be able to persuade the city to increase his budget next year to avoid thousands of future imaginary mass incidents.

[Julio747]

What makes me suspicious of the CO diagnosis is the method of recovery. Normally, the patients would be given oxygen to breath and that would reduce their CO levels by 50% every 80 minutes. Walking around in fresh air (as is reported) reduces CO levels (actually, the COHb level) by 50% every 320 minutes (https://en.wikipedia.org/wiki/Carbon_monoxide_poisoning#Treatment).

I think we need to consider this scenario: Many passengers smoked before boarding the plane - and those smokers had a lower tolerance for the reduced cabin air pressure. Some of these passengers and perhaps some others got sick during the flight so the flight landed. On landing, many of the sick passengers had elevated CO levels from smoking - but not elevated so much that the were offered oxygen therapy.

Regarding CO levels: Home detectors can detect 1 or 2 parts per million (ppm), flu-like symptoms start at 35 ppm, loss of judgement starts at 200 ppm, convulsions within 45 minutes at 800 ppm, death in less than 2 hours at 1600 ppm.

During a power outage in my town that lasted several days, I was with a volunteer group that worked with the Fire Department. We went home to home checking on the use of generators. Improperly positioned generators resulted in levels of 35 and 50 ppm at two homes. In both of those cases, fumes could be easily smelled. No symptoms were reported.

... or, there was CO on the plane and the low cabin pressure aggravated the effects of the CO poisoning.

Smokers fly every day, every flight (check out any airport smoking room). If smoking was the cause, it would happen every flight.

The CO diagnosis may turn out to be a red herring.... But smoking? No... We do not need to consider that. It is nonsense.

[.Scott]

My point was that the fire chief could have detected COHb even if there was no CO on the plane. We both hold as suspect the suggestion that cabin CO caused the problem. But there are portable devices that can check for COHb - either from breath or from blood.

One passenger reported that pax from different parts of the plane actuated their call buttons at about the same time. This suggests that CO or not, there may have been a real (non-psychosomatic) cause for the illnesses.

[jugofpropwash]

Could passengers have been exposed before getting on the plane? Perhaps a malfunctioning cooking appliance or a vent that wasn't turned on in the terminal, and they didn't feel the effects until the pressure dropped on the aircraft?

[Julio747]

My point was that the fire chief could have detected COHb even if there was no CO on the plane. We both hold as suspect the suggestion that cabin CO caused the problem. But there are portable devices that can check for COHb - either from breath or from blood.

Okay, get your point. But I don't buy it (smokers I mean..) Anyone using such equipment would be trained to interpret the result.

I think the post that followed, about exposure on the ground exacerbated by lower pp of oxygen at altitude, is much more plausible.

Re: other posts. I believe A/C have electric ovens not gas ones! Oven linings do not contain carbon, hence not a possible source of CO. Not a lot of CO from electrical fires. As for a smouldering fire somewhere, I think the pax might have noticed the smell of smoke (and perhaps a smoke alarm might have gone off) long before enough CO reached them.

As I have said, the CO call might be a red herring. But if real, then the only likely source is the engines or APU. There is a lot of fuel, it is burnt, and said fuel is mostly carbon... Occam's razor applies.

[misd-agin]

So nine people had symptoms and 70 to 140 people, breathing the same air, didn't ??

[oldpax]

I had a bad air fill when scuba diving ,my tank had been the first fill that day and vehicles were parked near the compressor intake.If you get CO poisioning you will certainly know about it!After about ten minutes into the dive I had a splitting headache which lasted all day !

[andrasz]

The CO component of the story has zero credibility:

For one, CO is the product of incomplete combustion of carbon compounds under oxygen deprived conditions AND high temperatures. The only place on the aircraft where it may be produced in measurable quantities (barring an on-board fire, which was clearly not the case) are the combustion chambers of the engines and the APU. As stated several times above, if the engines are producing thrust and there is sufficient airspeed to maintain flight, it is physically impossible for any CO produced there to enter the cabin air supply.

The fire chief was more than likely influenced by cognitive bias. They would have received extensive training on the effects of CO poisoning, as in case of victims of building fires swift recognition and treatment is vital. Naturally he would 'recognise' any condition with similar symptoms as CO poisoning, without considering other options. Very similar to doctors with different specialisations tending to come up with varying diagnoses matching their fields of expertise for the same patient.

[enginesuck]

Actually CO is produced from burning Hydrocarbons at too low a temperature, I tune Industrial Gas Turbines for low emissions for a living, and as an ex aircraft propulsion Tech i know a thing or three about Aero Derivatives, it seems unlikely that high CO (in excess of 50ppm) is produced from combustion in an Aero but it all depends on temperature really. As for how it would get into the cabin, i cant think of any mechanism unless there was an oil fire across the labyrinth seals of a bearing that would cause CO to enter the cabin. Oil would burn inefficiently and cold enough to produce tremendous amounts of CO - certainly in excess of 1000ppm

[Herod]

I don't think it's been mentioned yet, but what about organo-phosphate and mass hysteria? Just saying.

[.Scott]

The symptoms are wrong for organophosphates - and you can't walk off that type of poisoning.
I mentioned psychosomatic earlier, but one passenger reported that many call buttons where pressed from different sections of the plane at about the same time. So, on the face of it, it would seem as though there was not enough opportunity for pax-to-pax communication to support mass hysteria.

[jugofpropwash]

It would be interesting to know if those who displayed symptoms were people who might have been more susceptible - smokers, elderly, pre-existing medical issues, small children, etc.

[jugofpropwash]

Wow. I had no idea ethyl alcohol purges CO from the blood stream and sleeping increases CO levels in the blood stream.

Not a doctor, and pure speculation on my part, but - I'm assuming that those out drinking and partying were talking, laughing and moving around, which would lead to deeper breathing than their sleeping captain, who would have been breathing more shallowly. The more fresh air you have coming in, the more it will dilute and purge whatever is already in your system.

[Julio747]

Are you kidding?

I understand the circumstances for that to be possible. This was not one.

Dig deeper....