[Dioxin-l] Re: Poor efficacy of residual chlorine in drinking water distribution

[Jon Campbell]

David,

     I can't figure out whether you are being disingenuous or just not
understanding what you just wrote. Look at it again:

>	Except for Escherichia coli, microorganisms remained relatively
>     unaffected in water from the distribution systems tested. When
>     sewage was added to the water samples, indigenous thermotolerant
>     coliforms were inactivated only when water was obtained from
>     sites very close to the treatment plant and containing a high
>     residual chlorine concentration."

1. The abstract says first that other microorganisms are relatively
unaffected. This makes chlorine, at best, a poor choice because it provides
a false sense of security against the major vectors which cause disease from
water systems, that is, those other than e. coli. This is what Pat Costner
said in her last message.

2. The abstract says that coliforms (e. coli) are only inactivated ONLY when
water was obtained from sites VERY CLOSE to the treatment plant and
containing a HIGH residual chlorine concentration. This again makes chlorine
a poor choice because people think the residual chlorine is killing e. coli
throughout the system when it isn't. This is what Pat Costner said in her
last message.

Please, this debate is getting very silly. You keep on throwing up the
standard organochlorine industry straw men, and we keep on having to tear
them down. Are you reading from the a Chlorine Chemical Council flyer, or
what? This is getting very tiresome.

Why are you doing this, or should I ask, who do you work for?

This dioxin list has been around for several years. If you want to see all
the arguments about this, you can read them in the archives. The intent of
this list is for dioxin researchers and activists to share information about
dioxin exposure and its reduction, not to waste our time tearing down
industry straw men.

Thanks
Jon Campbell

-----Original Message-----
From: david bell [mailto:burnt_paper@hotmail.com]
Sent: Tuesday, January 11, 2000 2:00 PM
To: pat.costner@dialb.greenpeace.org
Cc: dioxin-l@venice.essential.org
Subject: Re: [Dioxin-l] Re: Poor efficacy of residual chlorine in
drinking water distribution


Hi Pat
perhaps you can explain the wording of the abstract to me: I have not seen 
the paper, and do not know what information it contains.

>microorganisms remained relatively
>     unaffected in water from the distribution systems tested

I understand this-

>except for Escherichia coli

Can you please explain to me what this means ? Does this not mean that E 
coli is affected by water from the distribution systems tested ? Is this not

the wording of the abstract ?

If E coli is disinfected, is this not a good thing ?

If other bacteria and viruses are not inactivated, that is clearly a 'bad 
thing'; but you don't make the 'bad thing' better by adding another 
pathogen, E coli, to the mix.

david

>Dear Mr. Bell,
>
>I urge you to give the abstract of the study by Payment (1999)  a
>more careful reading.  You have interpreted it to say that "E coli is
>inactivated by residual chlorine throughout the distribution
>system."  This differs considerably from the actual wording of the
>abstract, as follows:
>
>     "Except for Escherichia coli, microorganisms remained relatively
>     unaffected in water from the distribution systems tested. When
>     sewage was added to the water samples, indigenous thermotolerant
>     coliforms were inactivated only when water was obtained from
>     sites very close to the treatment plant and containing a high
>     residual chlorine concentration."
>
>You then note, " Given that E coli is a principal contaminant of
>sewage (and in turn the water supply system), and can be highly
>pathogenic (eg E coli 0157), this abstract can easily be used to
>  make a case for chlorination of water supplies."   With this, I
>  would suggest that you have missed a major finding of the study:
>
>     "Clostridium perfringens was barely inactivated, suggesting that
>     the most resistant pathogens such as Giardia lamblia,
>     Cryptosporidium parvum, and human enteric viruses would not
>    be inactivated. "
<snip>
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