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Re: dioxin fingerprints
hello again, folks
TCE formation by ordinary chlorination (with chlorine
bleach or elemental
chlorine) is pretty well documented, and appears in the
anecdotal
public press regularly. I can't point to a study this
moment, merely
because I didn't think it was particularly
controversial - it is accepted
as fact by the scientific community that I deal with on
a regular basis.
I'll attempt to find some studies on it. We are talking
about a few
ppb TCE in public water supplies that use chlorine.
Many publicly
owned water supplies have stopped using chlorine for
this reason.
A few months ago there was an article in The Boston
Globe about
the issue, that mentioned just in passing that there
was concern about
excess TCE in water supplies that needed to be treated
with more
chlorine than usual because of excess coliform. The
fact that TCE
was being formed was not part of the controversy; the
article
was talking about reducing the amount of TCE by keeping
the
water cleaner (fixing broken pipes, etc).
Now, dioxin formation is another matter. Anytime you
have
free chlorine around organics there is the opportunity
to
create dioxin. Heat and turbulence improve the chances.
Consider that in an ordinary washing machine you have
water temperatures of 140-180 F, a large amount of free
chlorine (500cc of bleach, which is 5% sodium
hypochlorite),
and large amount of organic material (500cc of sodium
laurel sulfate) agitated heavily. The amounts are
likely
to be very small. The studies are inconclusive; one
study
claimed that most of the dioxin in household washwater
was from garments treated with dioxin-contaminated
dyes and fabric "preservative" pesticides - another
source
I forgot to mention. Again, as in the case of chlorine
water treatment, there is no controversy about the
presence of dioxin in household wastewater, but much
about where it comes from...
Jon
-----Original Message-----
From: Susan K. Snow <sksnow@1stnet.com>
To: Multiple recipients of list
<dioxin-l@essential.org>
Date: Wednesday, August 06, 1997 2:40 PM
Subject: Re: dioxin fingerprints
>If I recall the lectures I've attended over the years,
many incinerator
>companies are said to have dumped their toxic waste
water (leftover from
>the process of rinsing air pollution controls and
creating of steam to
>produce energy) down the drains. Perhaps, this may be
the source of
>dioxin in POTWs.
>
>Susan Snow
>