Thread: h1n1 mark II

Originally Posted by Mikes defender

After reading the posts there are must be some medical people out there...

Is it true that those masks only last 10 minutes, and after that they are useless?

mike

As someone who has been doing filtration research for many years (and since the respirator manufacturers like citing one of my papers), I feel qualified to comment on this. Also since I recently attended a conference where the head of respirator research at 3m discussed this very issue...

Some important points:
(1) Surgical type MASKS do NOTHING. They are designed to stop doctors infecting their patients. They are only effective at catching large diameter droplets leaving the mouth of the wearer. Surgical masks do not seal and have no legislated filtration efficiency requirements.
This is a surgical mask:

This is also a surgical mask:


Both of the above offer no protection against you inhaling (viable) virons.

(2) RESPIRATORS give you some protection, but only if they SEAL AGAINST YOUR FACE PROPERLY. Respirators are designed to protect the wearer from inhaling particles/droplets (unlike surgical masks). The highest class of disposable particulate respirators, are P1 (Aust.) = N95 (US).


Notice that they have 2 STRAPS, and they are clearly marked with their rating (P1/N95, etc), and the standards they conform to.

NB: If you have facial hair (or even 3-day stubble), the respirator fit will be compromised and its efficiency will be severely reduced - often rendering it next to worthless.

After a period of time (hours-days) depending on conditions, the respirator will have collected enough "liquid" droplets/moisture that it will begin GENERATING small droplets as well as collecting them.

SO - the message is:
Unless you are wearing a P1/N95 respirator, it probably isn't worth bothering
If you have facial hair, it probably isn't worth bothering.

A leading US epidemiologist thinks that anyone diagnosed/infected with swine flu should be forced to wear a respirator, to limit their potential to cause infection. Which is actually quite a good idea.

Originally Posted by JDNSW

I just would have assumed everyone knew about it, at least vaguely.

Ditto. When I referred to the media, it has been mentioned quite often of late but I've known of it for many, many years.

Thanks for your input guys.

Working in the airline industry i see a wearing those masks. it will be interesting to see if they comply..

Originally Posted by dullbird

Yes seriously.....it was never covered in history Ron so why would I know.

I'm not the sort of person that researches pandemics unless one is on the horizon

Not dissing you Lou, but I thought it was a sort of general knowledge thing too, and I'm not quite in JD's or Ron's, err, period of maturation just yet

Having said that, my SO only 'discovered' it a few months back (pre swine flu) while watching a doco.

BTW, last figures I saw claimed at least 2500 people died from the 'normal' flu strains each year in Australia.

Originally Posted by Mikes defender

Thanks for your input guys.

Working in the airline industry i see a wearing those masks. it will be interesting to see if they comply..

I flew to the US at the height of the (initial) swine flu scare. I only saw 1 or 2 people wearing masks, until the final flight home from LA-Syd, where there were 5 or 10 people on the plane wearing masks. Note I said MASKS, not respirators. ALL were wearing surgical masks or non approved 1-string ppe type masks. Some were wearing them upside down, some had them fitted loosely so there were huge air gaps. It was all I could do not to burst out laughing...

Some interesting points raised by the leading epidemiologist I mentioned above during his keynote speech:
(1) Pandemic flu shows no seasonality whatsoever (unlike "seasonal flu")
(2) Each new pandemic flu, will, over the course of 3-5 years, become the next seasonal flu.
(3) Border controls do NOTHING, and there is no way to predict which areas will be worst affected. e.g. the example he used was the flu epidemic after WW1. Most of europe was raviged by war, yet the country worst affected by the flu pandemic was Switzerland, which was neutral during the war, so unaffected, and had comparatively little traffic through it.

Originally Posted by isuzurover

If you have facial hair, it probably isn't worth bothering.

That's about 90% of Land Rover owners in trouble then

Originally Posted by isuzurover

I........
(3) Border controls do NOTHING, and there is no way to predict which areas will be worst affected. e.g. the example he used was the flu epidemic after WW1. Most of europe was raviged by war, yet the country worst affected by the flu pandemic was Switzerland, which was neutral during the war, so unaffected, and had comparatively little traffic through it.

But during this epidemic, according to Wikipedia "Several Pacific island territories were particularly hard-hit. ....Worst affected was Western Samoa, a territory then under New Zealand military administration. A crippling 90% of the population was infected; 30% of adult men, 22% of adult women and 10% of children were killed. By contrast, the flu was kept away from American Samoa by a commander who imposed a blockade."

But I agree today border controls are likely to be quite ineffective - too many people doing too much travel too quickly.

John