Fullwings, as an ultimate 'stakeholder' Perhaps you would like to review the factual evidence and help come up with a well balanced conclusion?
That's a big job, currently being worked on by far better qualified people than myself and I don't see a conclusion even on the horizon yet...
I've just ploughed through some of the reports from the CoT (a distillation of a small amount of what's out there) and it definitely reads like a work in progress. Many small studies of various factors but very little in the way of
statistical significance - and that's the main issue, for me.
Are some aviation workers becoming ill with chronic nervous disorders? Yes. Are there 'fume events' occurring on some aircraft? Yes. Is there a causative relationship between the two? Not yet proven/disproved. Are we seeing a much greater incidence of these ailments than you would expect in a general population sample? Wasn't obvious from anything I've read.
'Control group', 'confounding variables', 'selection bias', 'significance level', 'blind trial'... These are the sort of phrases you hope to see when, say, a new drug is being brought to market and is undergoing toxicity testing. At the moment, much of what I'm looking at reads more like a sociological study because of the lack of empirical data.
One thing that did strike me (and others) is the fixation on TOCP synthesised from engine oils as being "the problem". I'd have thought a more holistic view was in order, given that we are operating in a wholly manufactured environment. There are plenty of possibilities for other neurotoxic compounds and vectors which may be being overlooked.
There are striking parallels with "Gulf War Syndrome" and it took long enough to come to some statistically valid conclusions - and that was with a 700,000 person sample with 1 in 4 affected! It was the Uranium shells, then it was the Anthrax vaccinations, etc. In aviation we're looking at something that is hovering around the noise floor: I saw a rough estimate of 3-15
thousand monitored flights on the 146/757 in order to gather appropriate data.
Boeing worked it out in around 1999 (hence the B787)
Maybe they did but I'd suspect the major drivers for an electric system would be decreased weight, cost, maintenance and fuel burn (all popular with the airlines).
Radiation, pathogens, nasty fumes, low humidity, epidermal bits floating around... An aircraft is a terrible place to be! But hang on, all these things are around at ground level, sometimes in much higher concentrations. Many have been environmental issues since the start of evolution. You can't take these things in isolation.
Just suppose that filters (activated carbon?) were fitted to all bleed-driven aircraft, 'just in case'. A wise move, in view of the 'precautionary principle', even though we don't fully understand the problem? It would make a lot of people happy and the industry would be seen to be 'doing something'. Imagine now that the problem wasn't what we'd thought it was but something else, equally as nasty, that had been overlooked... How long until that was found because "it's all OK now."?
I don't want to be a 'believer', I want to be
convinced. So far I've seen very little that I could file under that heading but a lot from people with a very
personal interest in the subject - and they don't generally make the best impartial researchers, it has to be said. No offence intended - just the ways things are.