Hi, archangle.
I agree with 90% of your post, and disagree with one part of it. But it's a critical part, imho.
Let's start with what I agree with:
archangle wrote:there has been one diagnosed USA case of Nagleria infection from neti in recorded history.
Googling, I come up with 120 deaths*, but it's still a small risk: 120 <312,092,343 (USA population as of August 29th, 4:07am EST), about 3 deaths per year, says the CDC.
*
http://abcnews.go.com/Health/Wellness/w ... d=14328749
archangle wrote:If there's anything that bad in the tap water, I probably breathe it in aerosolized form when I shower anyway.
Agree there too, but with one proviso. Unless you're really into showering, I'd imagine you shower once, perhaps twice a day, each shower session lasting about 5 to 10 minutes.
Infections from pathogens, viruses and chemicals are dose-dependent. If there is something aerosolized in the water, I'd much prefer a 5 minute shower exposure than an 8 hour xPAP one.
Additionally, I'm guessing that most people using tap water to drink—or fill their xPAP tanks—use water from the cold pipe alone.
If you shower with heated water, you're mixing very hot and cold water.
In my building, the hot water from the hot pipe is steaming hot, so I'd venture that in the boiler room, the water is boiling.
Most pathogens have a thing about boiling water, so again, that 5 minute a day exposure is reduced even further.
________________________________________________________________________________________________________
Here's where we congenially disagree:
archangle wrote:No, it's not aerosolized or misted. It's evaporated.
I want to make sure that we're both agreeing on the definition of aerosol.
Wipedia wrote:With studies of dispersions in air, the term aerosol evolved and now embraces both liquid droplets, solid particles, and combinations of these
http://en.wikipedia.org/wiki/Aerosol
Thus, if I spray my hand with a bottle of Winex, I get aerosolized with different sized droplets, not just microscopic sized ones.
________________________________________________________________________________________________________
Reading your post, I tried this experiment: I filled my cleanable water tank for my ResMed S9 with cold water, up to the max line limit.
I put the tank in the S9, unhooked the hose from the unit, and turned out the lights, turned on a tiny LED penlight.
I started up the S9, no ramping, default pressure at 10.4 cmH2O. Put my hand in front of the S9's exhaust port, used the penlight to back-light the results for maximum contrast.
The water in the tank was cold. No time for evaporation. But I could see a spray coming from the port. In a minute my hand was dripping wet.
________________________________________________________________________________________________________
I redid the experiment, filling the water to the 3/4 mark.
This time, I dried all the parts of the tank (the cleanable tank can be disassembled) with a paper towel, eliminating the possibility that the water was from spillage inside the air chamber of the tank when I filled it.
Same result. Cold spray, clearly visible.
I shined the penlight into the S9 as it was running.
Of course, at first, I thought what I was viewing was (ps)2 + (.5 * r * V^2)2 = (ps)1 + (.5 * r * V^2)1 = a constant = pt (Bernoulli's Principle), that the increased air velocity in the tank's air chamber produced decreased pressure, and thus drew out water from the water tank in that manner.
But on closer inspection, I could see that the airflow speed and volume was causing the water in the water tank to roil vigorously, and so I suspect that was the cause of what I perceived to be clear aerosolization from the exhaust port.
________________________________________________________________________________________________________
There are a number of potential pathogens in tap water:
http://www.iwaponline.com/jwh/005/0427/0050427.pdf
Add this to the number of chemicals commonly found in tap water, and I can see why ResMed's pamphlet unequivocally states: "Use only distilled water" in your tank.
__________________________________________________________________________________________________________
OH NO YOU DIDN'T!
The concise version:
hosecrusher wrote:I actually ran a test on this and at a pressure of 8 cm H2O it seems that there is a small amount of aerosol action taking place.
I put some salt into the humidifier water and collected condensate from my mask. The condensate had salt ions in it. The only way to get salt ions into the condensate is if there is some aerosol action. Mind you it wasn't much, but there is a little more going on than simple evaporation.
Try it for yourself and let us know what results you get.
Posted while I was typing.