North American Fruit Explorers mailing list at ibiblio

[abb7@Lehigh.EDU]

> Message: 3
> Date: Tue, 8 Apr 2008 20:04:23 -0500
> From: "Ernest Plutko" <ernestplutko@wiktel.com>
> Subject: [NAFEX] CCA
> To: nafex@lists.ibiblio.org
> Message-ID: <380-22008439142393@wiktel.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> I'm wondering if CCA treated timbers will leach arsenic in the soil
> where fruit is growing.  I thought CCA was banned a few years but
> maybe not.  The lumber yard knows nothing when asked.

Arsenic from CCA treated timbers does leach into the soil.  Here is  
the abstract of one relevant study:
==========================================================
Sci Total Environ. 2006 Jul 1;364(1-3):113-23. Epub 2005 Sep 16. Links
Leaching of copper, chromium and arsenic from treated vineyard posts  
in Marlborough, New
Zealand.

Robinson B, Greven M, Green S, Sivakumaran S, Davidson P, Clothier B.
HortResearch, Private Bag 11 030, Palmerston North, New Zealand.
Brett.Robinson@env.ethz.ch
There have been conflicting reports as to the extent that  
copper-chromium-arsenic (CCA)
treatments leach from timber. In New Zealand, vineyards utilise  
CCA-treated posts at a
rate of 579 posts per hectare. This represents a potential CCA burden  
on the soil of 12,
21, and 17 kg/ha, respectively, for the three elements. Given a  
replacement rate of 4%
per year, the use of CCA-treated posts may result in an accumulation  
of these elements in
the soil, possibly leading to groundwater contamination. We undertook  
a general survey to
determine the extent of CCA leaching from treated vineyard posts.  
Treated Pinus radiata
posts were sampled at six sites around the Marlborough region of New  
Zealand to represent
a range of post ages and soil types. For each post, above- and  
belowground wood samples
were taken. As well, the soil adjacent to the post was sampled at a 50  
mm horizontal and
100 mm vertical distances from the post. The belowground wood samples  
of the posts had
significantly lower CCA concentrations than the aboveground portions,  
which were not
significantly different from new posts. This indicates leaching. Soils  
surrounding the
posts had significantly higher CCA concentrations than control soils.  
Higher CCA
concentrations were measured under the posts than laterally. Some 25%  
of the samples
exceeded 100 mg/kg As, the Australian National Environment Protection  
Council (ANEPC)
guideline level for As in agricultural soil, and 10% exceeded 100  
mg/kg Cr, the ANEPC
limit for chromium. At one site, we found a significant positive  
correlation between post
age and CCA-leaching. The CCA issue could be eliminated by using  
alternative posts, such
as steel, concrete, or untreated woods such as Eucalyptus or beech.  
Alternatively,
CCA-treated posts could, for example, be lacquered or otherwise  
protected, to reduce the
rate of CCA leaching.
============================================================

It's not really clear, as far as I can find, that this is a problem for fruit
growers....here is another abstract:

===========================================
1: Sci Total Environ. 2007 Dec 15;388(1-3):35-42. Epub 2007 Sep 24. Links
Mobility of copper, chromium and arsenic from treated timber into grapevines.

Ko BG, Vogeler I, Bolan NS, Clothier B, Green S, Kennedy J.
Environment and Ecology Division, National Institute of Agricultural  
and Science
Technology, 249 Seodundong Suwon, Republic of Korea.
The use of chromated copper arsenate (CCA) treated timber posts as  
support structures in
New Zealand vineyards has raised concerns regarding the release of  
heavy metal(loid)s
from the treated timber into the environment. A laboratory experiment  
was set up to
evaluate if post sealing by painting reduces the release rate of CCA  
metal(loid)s from
timber posts. Three posts were painted (Gripset 38, Multi Purpose  
Bitumen Rubber) on the
bottom part, submerged in freshwater, and the concentrations of copper  
(Cu), chromium
(Cr) and arsenic (As) in the water were monitored over a period of 8  
months. Three
additional, unpainted posts were also used. The CCA contents in the  
water showed a clear
difference between the painted and the unpainted posts, and painting  
the bottom of the
posts reduced the release rate by 50-75%. To monitor the possible  
mobility of CCA from
treated posts into grapevines further, an experiment with  
four-year-old grapevines
planted into sixteen lysimeters was set up in a greenhouse. To half  
the lysimeters Cu, Cr
and As were added to the soil surface at rates of 16, 20, and 12.5  
mg/month from 15
November 2005 to 5 May 2006. The other lysimeters acted as a control.  
Soil solutions were
collected at 50, 150 and 300 mm depths using suction cups after seven  
application of the
CCA solution. The results showed that all the elements moved to a  
depth of 50 mm. Grape
fruit, leaves and rachis were analysed for CCA metal(loid)s, but did  
not show any
differences between the CCA-treated and control lysimeters. This  
indicated either that
these metals were not taken up by grapevines or that their  
translocation from roots to
the upper part of the vine was negligible. Further monitoring of CCA  
metal(loid)s in
various parts of the grapevines, including roots, needs to be undertaken.
============================================

I haven't come across any for other fruits, but I have not looked very  
hard recently.

In any case, CCA treated timber is supposedly not sold in the US  
anymore.  I suppose there may be places that still have old stock.   
All the places around me now sell ACQ treated wood instead, and I have  
not seen CCA wood for a couple years.  The EPA hasn't found any  
problem with ACQ yet AFAIK.

When you say "The lumber yard knows nothing when asked.", are you  
referring to the availability of CCA treated wood, or the leaching of  
arsenic?  Surely they know what wood they are selling.

Alex



----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.