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Re: GSBN:Danny Buck's SB water problem- flashing

I like copper flashing.  I have read that in the San Francisco Bay area,
the copper levels in the water are a concern.  I haven't heard of this
being an issue in any other location, but as always, checking local
conditions is essential to making informed, site specific choices.

Some people worry about aluminum.  I am currently skeptical of the risk,
because aluminum is a light metal that is extremely abundant in the earth's
crust.  Humans, and indeed all land creatures, have evolved with continuous
exposure to aluminum compounds.  However, we may find that something about
our current exposure patterns introduces new risks.  Copper is recognized
as necessary for human nutrition, although in small amounts.  At the same
time, many common copper compounds are toxic, so the quantities and details
matter.  Lead is considered toxic in the range of parts per million, and
many scientists say, parts per billion.  There is clearly a large
difference in the level of risk in our exposure to different metals.


--On Wednesday, October 27, 2004 12:28 PM -0400 Strawnet@...:

Thanks Derek,

I was going to try to find the time to write about the lead issue - and
to suggest that some people like copper for this kind of flashing. Easy
to work with, nice looking if it shows, and a much smaller ecological
footprint than lead. Some people object to all metals, I know.


David Eisenberg, Director

Development Center for Appropriate Technology
P.O. Box 27513, Tucson, AZ  85726-7513
(520) 624-6628 voice / (520) 798-3701 fax
<a  target="_blank" href="http://www.dcat.net";>http://www.dcat.net</a>

Derek Roff
Language Learning Center
Ortega Hall 129, MSC03-2100
University of New Mexico
Albuquerque, NM 87131-0001
505/277-7368, fax 505/277-3885
Internet: derek@...