Text 16518, 89 rader
Skriven 2008-05-31 11:35:16 av Robert Bashe (2:2448/44)
  Kommentar till text 16497 av Björn Forsström (2:203/614.61)
Ärende: Misinformation
======================
Björn Forsström wrote to Robert Bashe on Saturday May 31 2008 at 08:22:

RB>> Lots of misinformation in that report, which we also got here.

RB>> First of all, it's a sodium hypochlorite solution, not "chlorine".
RB>> Sodium hypochlorite is used to disinfect small swimming pools in
RB>> Germany and presumably elsewhere, and the water in large ones is
RB>> actually chlorinated with compressed chlorine gas in flasks. Ever ger
RB>> a mouthful of water in a swimming pool? Most people do from time to
RB>> time, and "surprisingly" don't die of it.

BF> Why is it then not allowed to clean chicken with it here?

Panic and ignorance, the same as with the CO2 hype, where you can often read
that the gas is "poisonous". Laypersons don't distinguish between carbon
_mon_oxide (poisonous) and carbon _di_oxide (non-poisonous but not breathable,
in the same sense as nitrogen).

BF> And why did they evacuated the local public bath when one of those
BF> flasks started to leak?

Because that's pure chlorine gas that _is_ poisonous and corrosive to the
lungs. Incidentally, concentrated sodium hypochlorite is very alkaline and
corrosive, but at the dilution used for pools harmless. Also, I may have made a
mistake in the cation... I think they use calcium hypochlorite, not sodium
hypochlorite in pools because the calcium hypochlorite is more stable in
storage.

RB>> Secondly, the meat is washed with plain water after disinfection to
RB>> remove "nice" things like salmonella. So the residue, if any, is
RB>> negligible. Would you rather stick your tongue in the chlorinated
RB>> water of a swimming pool or eat chicken contaminated with salmonella?
RB>> I think there's only one honest answer to that.

BF> Since we don't use chloorine there must be other ways of disinfect it
BF> from salmonella.

Either that, or there is no disinfection here. In the former case, it would be
wise to find out precisely what is being used and what negative effects _it_
has (anything with _any_ effect has both positive _and_ negative effects). In
the latter case, better cook your chicken well done. Incidently, in Germany the
authorities caution against letting chicken thaw in it's own juice for
precisely the reason that the meat can become contaminated with salmonella.
Maybe that doesn't tell you anything, but it sure does me.

RB>> Thirdly, many laypersons - in particular politicians - get all hot
RB>> and bothered when they hear the word "chlorine" because in their
RB>> technical ignorance they don't realize every swimming pool is
RB>> disinfected with chlorine or a chlorine-containing chemical. Only
RB>> rarely are swimming pools disinfected with ozone, and that has it's
RB>> own set of disadvantages.

BF> Too much of either isn't good.

Too much of _anything_ is not too good, to paraphrase a Disney song of long
ago. But panic and misinformation are bad advisors. Remember "dihydrogen
monoxide".

RB>> So what's all the hype about? Why don't the same politicians and
RB>> "gurus" who get excited about people disinfecting meat with a dilute
RB>> hypochlorite solution and then washing it off also close all swimming
RB>> pools?

RB>> That's an easy one: Such hype sells newspapers and magazines, and in
RB>> the case of politicians talking to uneducated voters can gain said
RB>> politicians votes for "protecting" the public against a danger that
RB>> doesn't objectively exist.

BF> So: http://www.bt.cdc.gov/agent/chlorine/basics/facts.asp is not true
BF> at all?

Are you not aware of the fact that there is a difference between chlorine gas
and the dilute solutions of chlorine in water, for example in swimming pools? I
might also mention that a lot of city drinking water is chlorinated as well.
Doesn't taste that great, but nobody has died from it yet.

Chlorine gas was used as a war gas in WWI, and although not very effective (it
dissipates too easily), was pretty unpleasant for the soldiers who inhaled
higher concentrations.

However, I sincerely doubt that anyone would try to incapacitate soldiers by
letting them swim in a pool filled with chlorinated water - they might enjoy
that to cool off, but it would increase rather than reduce their fighting
morale.

Cheers, Bob

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