Latest research: Bleed Air Ducts can not be cleaned, pollutants penetrate human body

[tupungato]

Latest research: Bleed Air Ducts can not be cleaned, pollutants deeply penetrate human bodies: News: Latest research: Bleed Air Ducts can not be cleaned, pollutants deeply penetrate human bodies (http://avherald.com/h?article=4d29bcec&opt=0)

Summary of research: Aircraft Cabin Air, Hamburg University of Applied Sciences (http://cabinair.profscholz.de/)

[jimmievegas]

It is interesting that Prof. Scholz talks a lot about cabin air in the media, but not to other scientists. As far as I have ascertained, he's got no peer-reviewed papers on the subject from the last half-decade. It's a pity that he doesn't allow scientists the chance to professionally comment on his work.

[tupungato]

Somewhat related: https://www.seattletimes.com/business/boeing-aerospace/flight-attendants-sue-boeing-over-design-they-say-caused-toxic-cabin-air/

Flight attendants sue Boeing over design they say caused ‘toxic’ cabin air

(...)
The contamination occurred on a Boeing 767-300 Delta flight from Frankfurt, Germany, to Detroit on Feb. 5, 2018, according to the lawsuit. A number of passengers became sick because of the contaminated air and the captain decided to divert the flight, the suit alleges.

“As a result of this event, Plaintiffs have suffered loss of wages and wage-earning capacity in the past and in the future,” the suit states.
(...)

[meleagertoo]

Anybody who flew on the 146/RJ's know the effect of flying on an inherently sickening aircraft :yuk:
With respect, clptrap. Utter claptrap.

I flew on the 146 as have millions of people and very few indeed have suffered anything, let alone all of them as you have rather ludicrously claimed. Quite what an inherently sickening aircraft is I cannot imagine. Aircraft don't suffer sickness afaik.

Furthermore, far from having flown on the 146 once, I flew it 5 days a week for 2 years and didn't find any adverse effcts, and to my knowledge neither did any of my colleagues, many of whom flew it far longer and one I know who is still flying it after the best part of 30 years.

Quite what your agenda is I can barely imagine, bit slagging the 146 off in such a bizarre and irrational manner lends it nothing but a healthy measure of ridiculousness.

[marchino61]

It is interesting that Prof. Scholz talks a lot about cabin air in the media, but not to other scientists. As far as I have ascertained, he's got no peer-reviewed papers on the subject from the last half-decade. It's a pity that he doesn't allow scientists the chance to professionally comment on his work.

As a scientist myself, I have to agree. His website lists a huge number of presentations and one paper, but not one of them is peer-reviewed. Clicking on the link to "selected papers" gets you a 404 error.

[Vendee]

With respect, clptrap. Utter claptrap.

I flew on the 146 as have millions of people and very few indeed have suffered anything, let alone all of them as you have rather ludicrously claimed. Quite what an inherently sickening aircraft is I cannot imagine. Aircraft don't suffer sickness afaik.

Furthermore, far from having flown on the 146 once, I flew it 5 days a week for 2 years and didn't find any adverse effcts, and to my knowledge neither did any of my colleagues, many of whom flew it far longer and one I know who is still flying it after the best part of 30 years.

Quite what your agenda is I can barely imagine, bit slagging the 146 off in such a bizarre and irrational manner lends it nothing but a healthy measure of ridiculousness.

I don't think it is claptrap. I worked as a propulsion technician on the 146 for 12 years. It was a smelly aircraft. Originally the aircraft had a catalytic converter fitted to each of the engines air offtakes, to remove some of the pollutants but these were removed early on (possibly because they broke up and fell back into the engine). The company I worked for had a fleet of ten 146's and we changed our engine oil types several times to try and mitigate the problems.... without much success. The ALF 502 engine seemed to burn oil quite a bit but of course, given the engine's heritage, its no surprise really.

[Herod]

Vendee. Looking at your location, you were probably engineering the aircraft I was flying. I agree it's not claptrap, and I think we probably know a few people in common who suffered brain disease. "Possibly" (avoiding litigation there) caused by organo-phosphates. Like smoking, one person can be a 40 a day type and live to a ripe old age: another can have one cigarette and die of lung cancer. Susceptibility I suppose, but unnecessary exposure isn't healthy. I was only flying it for some four years, but I do know others who clocked up well over twenty years.

[SpringHeeledJack]

I've had the unpleasant experience of what I concluded to be toxic-air poisoning twice in over 30 years of air travel, on many types/countries/airlines. The two types were the146 and 757. Both times I remember smelling a slightly eggy/sulphury odour in the cabin. Both flights were 2hrs or less. The next day I had a debilitating headache, body weakness and a generally hung-over sensation. No alcohol or other things were consumed. It lessened over several days. I remember chatting with an aero-engineer who opined that there was a bit of history (allegedly).

[Vendee]

Vendee. Looking at your location, you were probably engineering the aircraft I was flying. Yes, having read some of your previous posts, I believe you are right.

[LAME2]

One of many threads I found

https://www.pprune.org/rumours-news/506344-toxic-cabin-air.html?highlight=146+bleed

[AerocatS2A]

I've had the unpleasant experience of what I concluded to be toxic-air poisoning twice in over 30 years of air travel, on many types/countries/airlines. The two types were the146 and 757. Both times I remember smelling a slightly eggy/sulphury odour in the cabin. Both flights were 2hrs or less. The next day I had a debilitating headache, body weakness and a generally hung-over sensation. No alcohol or other things were consumed. It lessened over several days. I remember chatting with an aero-engineer who opined that there was a bit of history (allegedly).

The smell was someone’s fart. The feeling you had the next day was from dehydration.

I’ve spent a few hours in 146s. They had a bleed mod done that was supposed to have fixed the oil fumes issues and I didn’t have much problems with them personally. The APU could also be a culprit. I found the Dash 8 worse. The logic of high pressure and low pressure air supply switching meant that it could switch to low pressure bleed when the pressure was too low to adequately pressurise the oil seals.

[Less Hair]

BTW: Why are those front lavs and cockpits connected to the same ECS air flow recirculation zone?

[snooky]

With respect, clptrap. Utter claptrap.

I flew on the 146 as have millions of people and very few indeed have suffered anything, let alone all of them as you have rather ludicrously claimed. Quite what an inherently sickening aircraft is I cannot imagine. Aircraft don't suffer sickness afaik.

Furthermore, far from having flown on the 146 once, I flew it 5 days a week for 2 years and didn't find any adverse effcts, and to my knowledge neither did any of my colleagues, many of whom flew it far longer and one I know who is still flying it after the best part of 30 years.

Quite what your agenda is I can barely imagine, bit slagging the 146 off in such a bizarre and irrational manner lends it nothing but a healthy measure of ridiculousness.

I flew the 757 5 days a week for 20 years and now have many of the symptoms described in aerotoxic syndrome, enough to qualify for a disabled person badge at least.
We regularly smelled the sweaty socks odour, particularly at the beginning of the top of descent as the throttles closed, but didn’t realise its harmful effects.
In my case blood tests showed unacceptable levels of several chemicals contained in aircraft engine oil. I also understand why it has affected me and not some others, in that genetic testing revealed that I am not good at removing toxins.
Incidentally others that I flew with for many years have suffered aerotoxic symptoms, some fatal,
To hear the problem described as utter claptrap despite mounting evidence is very annoying.

[meleagertoo]

snooky, best you try reading what was written...
The claptrap I referred to was the idiotic assertion by Aso who stated that everybody who flew on the 146 suffered it. Presumably this included all pax...clearly an utterly ludicrous remark.

I'm not going to comment on individual's perceptions of how they remove 'toxins' but feel that as every human being has the same basic physiology and chemistry it seems pretty unlikely that this is a scientifically accepted theorey. It is certainly not one I have ever heard before.

The fact remains that I know of no one who flew the 146 with me who suffered this syndrome. I am thus, I think, entitled to be sceptical about it's veracity as a universal result of flying the 146.

[The Range]

I flew the 757 5 days a week for 20 years and now have many of the symptoms described in aerotoxic syndrome, enough to qualify for a disabled person badge at least.
We regularly smelled the sweaty socks odour, particularly at the beginning of the top of descent as the throttles closed, but didn’t realise its harmful effects.
In my case blood tests showed unacceptable levels of several chemicals contained in aircraft engine oil. I also understand why it has affected me and not some others, in that genetic testing revealed that I am not good at removing toxins.
Incidentally others that I flew with for many years have suffered aerotoxic symptoms, some fatal,
To hear the problem described as utter claptrap despite mounting evidence is very annoying.

How long ago did you stop flying? And do blood tests still show those chemicals in your blood?

[marchino61]

I'm not going to comment on individual's perceptions of how they remove 'toxins' but feel that as every human being has the same basic physiology and chemistry it seems pretty unlikely that this is a scientifically accepted theorey. It is certainly not one I have ever heard before.


Nonetheless, the scientific literature has a reasonable number of papers that do assert that genetic make-up affects the clearance of organophosphates from the body. This is just one of many ways in which people vary based on their genes. For example, caffeine has no effect on me because I am a "caffeine fast-metaboliser". This can be explained by a gene variant.

Here is just one article about organophosphates and genes:
https://www.liebertpub.com/doi/full/10.1089/dna.2012.1961?casa_token=UIgIOvvoDPoAAAAA%3AGePf1_VrB2H6Fk2-Ftd9xxH9mpTYTccElVKqB5pz_LDx3uUpuK33N1m5dz_CSMnAN0DlxRl2msFo lpk

Nine case–control studies were assessed with a total 1,042 patients with organophosphate toxicity and 1014 healthy controls. The meta-analysis results showed that the PON1 192Q and 55L polymorphisms may increase the risk of organophosphate toxicity. Further subgroup analyses by ethnicity showed significant associations of the PON1 192Q and 55L polymorphisms with increased risk of organophosphate toxicity among the Caucasian populations.

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[snooky]

How long ago did you stop flying? And do blood tests still show those chemicals in your blood?

I had the blood tests 5 years after I retired. In particular there were unusually high levels of benzine and toluene. Under medical advice I have now reduced these and other chemicals found to acceptable levels.
My dna tests resulted in a 60 page report, a small part of which showed that I had a particular genetic deficiency in removing toxins, perhaps explaining why I have had more effects than others similarly exposed to 757 bleed air.
There will possibly never be certainty in this matter, but given that aircraft bleed air has been shown to contain toxins I think that it is likely that it has had a detrimental effect on some peoples’ health. Possibly one day it will be seen as a scandal that this was allowed to continue as more and more evidence came to light.

[N707ZS]

We say all of this about aircraft but just think how many hours we drive around congested roads breathing in car fumes.

[Ben_S]

Yes, but car fumes, whilst not good for you, don't contain organophosphates.

[jimmievegas]

Yes, but car fumes, whilst not good for you, don't contain organophosphates.Car fumes can contain organophosphates. If you want an example of real, peer-reviewed, science then search for: "Occurrence of organic phosphates in particulate matter of the vehicle exhausts and outdoor environment – A case study"

[BRE]

Yes, but car fumes, whilst not good for you, don't contain organophosphates.

Actually, are fully synthetic, high performace 0W30 car motor oils free of organophosphates?

[JustinHeywood]

Snooky, I realise you may have simplified of 'dumbed down' your post for the general audience, but a couple of points caught my eye:

I had the blood tests 5 years after I retired. In particular there were unusually high levels of benzine and toluene.

What symptoms led you to get tested for benzine and toluene 5 years after you stopped flying?

..."genetic testing revealed that I am not good at removing toxins"

Can you add some detail to that?

[snooky]

Snooky, I realise you may have simplified of 'dumbed down' your post for the general audience, but a couple of points caught my eye:



What symptoms led you to get tested for benzine and toluene 5 years after you stopped flying?

..."genetic testing revealed that I am not good at removing toxins"

Can you add some detail to that?

Having spent years having tests including many mri scans to explain cardiac problems then neuropathy and other symptoms often associated with aerotoxic syndrome I had blood tests privately. I had exhausted the nhs system including their “clinical pathway” with no diagnosis.
The blood tests found raised levels of many of the contents of aero engine oil which was unsurprising considering I had regularly smelled it in 20 years flying the 757.
By avoiding toxins, following organic diet and supplements within a year the toxins were down to normal levels.
Under medical advice I chose to have dna tests to possibly explain my symptoms and in a very long report found that my genes whilst good at absorbing toxins were not good at removing them.
I feel satisfied personally to have explained my health problems. I do know of others who flew the same aircraft as me who have had health problems at relatively young age, some fatal.
In my carreer I did have 2 “fume events” requiring oxygen use, but I believe that the main problems stem from the very small doses to which I was exposed on most days.
I would certainly encourage current crew to take any unusual odours in flight very seriously and use oxygen if in any doubt.

[Gauges and Dials]

[...] but feel that as every human being has the same basic physiology and chemistry it seems pretty unlikely that this is a scientifically accepted theorey[...]

Humans differ quite a bit. Some of us (European ancestry, mostly) can easily digest cow milk as adults. Most humans have a hard time with it, and drinking a big glass of milk leads to hours of cramps and misery. Some of us have livers that make plenty of the enzyme alcohol de-hydrogenase; others (some East Asians and others) make much less, and experience headache and flushed skin after one drink. It doesn't surprise me a bit that, for any given toxin, there's quite a bit of variation in how fast our bodies clear it.

[JW411]

Well that explains it all. I am Scottish and I survived the 146 for 19 years without a single symptom. Mind you, I didn't drink any milk either.

[Longtimer]

Well that explains it all. I am Scottish and I survived the 146 for 19 years without a single symptom. Mind you, I didn't drink any milk either.
Did you sub. Scotch for the milk? Perhaps a natural remedy.

[silverstrata]

With respect, clptrap. Utter claptrap.
I flew on the 146 as have millions of people and very few indeed have suffered anything, let alone all of them as you have rather ludicrously claimed. measure of ridiculousness.

With respect, I don’t agree. We had many a fume events on 146s (containing organophosphates), from leaky seals.
And worse of all was the APU, which could fill the cabin with blue smoke (containing organophosphates).
We had many crew with long-term headach issues, that were never resolved until retirement...

Silver

[ExSimGuy]

I've been on this forum for many years (decades!), and this rings bells -- I'm pretty sure this has come up (several times?) before :eek:
Surely this repeated subject should have been thoroughly invesigated by now and if validated a solution found by now?
(I have to admit that most of my long-distance flying too place at heightd limited ton20nfeet above ground with BA at LHR many years ago :))

[cashash]

The reports of crews suffering from fumes from BA's 757 fleet have been around for decades - I dont know if you get more claims about BA rather than other operators because they mainly used the 535C engines and not the E4's or because they did have a larger fleet than most.

[snooky]

Worth a look for anyone interested in this https://www.everybodyflies.com/

[The Range]

Snooky,
What kind of tests do I need to get done if I suspect that I could've been affected by toxic cabin air? What would I have to look for?

[snooky]

Snooky,
What kind of tests do I need to get done if I suspect that I could've been affected by toxic cabin air? What would I have to look for?

Apparently tests within 48 hours of exposure are ideal. In my case I was not tested till about 5 years after retirement, but many constituents of jet engine oil were found to be at unacceptable levels. In particular benzine and its derivatives and toluene. In my case organophosphates were at acceptable levels, I think that these are normally found soon after a “fume event”.
I had the tests done at Biolab (https://www.biolab.co.uk/) under the advice of a doctor, who viewed the results and set out a regime to achieve acceptable levels.

[RatherBeFlying]

Studies have demonstrated that people living near high traffic roads. Fortunately lead free gas has resulted in a decrease of blood lead levels in children in these areas.

Hopefully further analysis will reveal just what substances have been found deposited inside the bleed air ducts of dismantled aircraft. Remember though that volatiles may just pass through.

At present aircrew are involuntary contaminant detectors to a far greater degree than the pax.

[The Range]

snooky,
Thank you for sharing all that info