A shadow cast
Recent research has just cast a large shadow over the use of wooden
materials treated with the CCA systems. It seems that Chromium,
Copper, Arsenic treatments have an environmental risk of releasing
traces of the two heavy metals but what is of most concern is the
slow release over a number of years of arsenates.
Arsenates are
a known carcinogen and have been directly linked to
some soft tissue cancers. It was previously thought Arsenates
only leached out of wood treated with CCA for the period
of time the wood was obviously "wet";
but new research has shown that leaching in year three
is as great as at year one.
Disturbing findings
The University of Florida and the University of North Carolina
have recently published these disturbing findings that seem likely
to have CCA treated products banned by the Environmental Protection
Agency of the United States Government.
>> Click here to
visit
References on Arsenic Treated Wood.
Closer to home
Closer to home it appears that the Marlborough District Council
has grave concerns over leachates in their water catchment
areas and are most disturbed over the Rarangi district
which has been earmarked for viticultural development but could
be susceptible to leachate with it's high water table.
>> Click here to
view an article from The Marlborough Express.
Further reading: Results of an initial survey
of the leaching from treated posts in vineyards is available
from the Marlborough City Council, Order No. 9159. A summary is
available here.
The environmentlly friendly alternative
The pre-stressed concrete post is, of course, totally environmentally
friendly and is ideal in high water table areas as it cannot be
degraded by rust or salt exposure.
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