ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************
Funny story about "hygiene"... I used to work in biomaterials industry. We
had these controlled temperature and humidity ovens (CTH), routinely tested
inside for all sorts of organism load. The feedtanks grew this incredible
green stuff, but the ovens never failed the regular tests. The hygienists
went ballistic when they saw all the green, so we instituted regular
bleaching. Suddenly, we were failing organism tests fairly frequently.
Pathological biological load is influenced by competition. There are all
sorts of benign organisms that are very successful but easy to kill without
creating significant endotoxins (the husks of bugs, often very toxic) and
out-compete hazardous organisms. Clear-cutting the flora and fauna allows
all sorts of more fragile, or sport (mutated) organsims to thrive to later
cause trouble. Same reason I encourage people not to use antibacterial soap.
All soap is antibacterial, but the main reason, I think, that washing works
is that it decreases the biological load, and removes endotoxins, but leaves
small quantities of the native, and therefore relatively benign, culture to
survive to repopulate the surface.
Aren't there aquarium and pond products that work along these lines that
might keep water exhibits safer? Alternatively, wouldn't it be possible to
put a 2 ?m filter on the feed lines? A suitable filter will screen out bugs,
leaving nice, clean water. Either of these approaches also provides an
opportunity to teach practical evolution and organism science.
Tom.
-----Original Message-----
From: Informal Science Education Network
[mailto:[log in to unmask]]On Behalf Of jason jay stevens
Sent: Tuesday, February 21, 2006 12:34 PM
To: [log in to unmask]
Subject: Re: Fog wall question
ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related
institutions.
****************************************************************************
*
> Using a very strong bleach can actually create a worse
> problem because a perfectly sterile surface is more likely to allow
> the
> growth of the "bad" bacteria. Most naturally occurring bacteria
> actually
> prevent the growth of the more nasty variety.
Drop that Clorox!!!
Is there corroboration for this?
Bleach is used everywhere for disinfection...to assert that it
actually promotes the growth of more nefarious germs is revolutionary.
How is bacteria growth tested, anyway?
Those MythBuster fellows on TV tested toothbrushes that they
strategically placed all around the house, to determine if putting
your toothbrush on the back of the toilet is any worse than, for
example, hanging it up next to the medicine cabinet or putting it
under a bell jar in the kitchen. They followed a scheme of using a
different toothbrush every time they brushed, and putting it back in
the same place.
At the end of the test period, every single toothbrush tested
positive for fecal coliform, including the one under the bell jar.
I think they implied that they sent the brushes to a lab.
Pleasant thoughts,
Jason
JasonJayStevens
[log in to unmask]
www.potterbelmar.org/spoke
***********************************************************************
More information about the Informal Science Education Network and the
Association of Science-Technology Centers may be found at
http://www.astc.org.
To remove your e-mail address from the ISEN-ASTC-L list, send the
message SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]
***********************************************************************
More information about the Informal Science Education Network and the
Association of Science-Technology Centers may be found at http://www.astc.org.
To remove your e-mail address from the ISEN-ASTC-L list, send the
message SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]
|
