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Tilting and vacuum treatment - two methods to obtain a non-dripping freshly treated timber
1989 - IRG/WP 3535
Modern impregnation plants are designed to prevent spread of impregnation solutions from the plant through leakage, etc. It is also important that freshly treated timber does not spread solutions through dripping on the storage area. To prevent this, the impregnation procedure is terminated with a vacuum period. In many plants in Sweden this period is minimized or even excluded to gain time. Instead the freshly treated timber is tilted for some time before it is transported to the storage area. To evaluate the effect of these two methods to get a non-dripping freshly treated timber a small study was carried out by the Swedish National Testing Institute (SP) together with the Swedish Wood Preservation Institute (SWPI).
I Johansson, M-L Edlund


Laboratory investigations about the mobility of some inorganic wood preservatives in soils
1998 - IRG/WP 98-50101-22
Wood preservatives and components of wood preservatives leached from impregnated wood can enter the soil and thus contribute to the pollution of the groundwater. However, there is lack of understanding concerning the interacting parameters of wood preservative, leachate, soil and soil solution. To characterise of the behaviour of active ingredients and for the assessment of their environmental impact, leaching and diffusion processes are of basic interest with which the concentration of the relevant ions in the soil solution is determined by the reactivity of the ion, and by the type of linkage between the ion and the soil. The concentration and the specific behaviour of the ions in the solid and liquid phases can be investigated using different methods, e. g. using soil column tests (lysimeter). Several designs of lysimeter have been tested with water-soluble wood preservatives and the results been compared with the behaviour of wood preservative components leached from impregnated wood. As a result of the variability of the experimental set-up, of the wood preservatives and of the different soils tested, it became obvious that a standard procedure has to be developed. By means of some examples of varying results the similarities and differences of different procedures are discussed.
E Melcher, R-D Peek


The collaborative developement of soil acceptance criteria for timber treatment chemicals in New Zealand
1995 - IRG/WP 95-50040-34
In New Zealand, the issue of potential contamination on timber treatment sites arose in the late 80's due to the long history of use of PCP by the industry. One of the recommendations from the task group set up to investigate the issue was the development of a set of acceptance criteria to define trigger levels for remediation. A technical group from the government, industry and regional councils supported by experienced environmental consultants was formed by the Ministry for the Environment to prepare the criteria. Guidelines for soil and landfill criteria were drafted covering the commonly used preservative products based primarily on human health risk exposure. Guidelines were also developed for specific beneficial uses where other risk exposures may dominant. The guidelines have been peer reviewed and issued in draft form for public comment. Several benefits have flowed from this process namely, a relatively short timeframe, low cost, multiple party ownership, practicality of application and ease of administration.
H C Boyd


Inorganic wood preservative levels in soil near a noise barrier treated with different preservatives after 8 years in service
2005 - IRG/WP 05-50234
In March 1996 nine test sections of a noise barrier were installed near Stockholm Sweden. The test sections include untreated Scots pine, spruce and larch and Scots pine, treated with different wood preservatives. After 8 years in service, the untreated spruce, pine and larch boards in contact with the soil were significantly decayed, with an estimated service life of about 5-10 years, while the untreated wood above ground is stained but not visibly decayed. Some degradation was detected in wood in soil contact for some of the preserved pine sections treated to AB levels (i.e. use class 3, above ground). Soil samples were collected at three horizontal distances from the barriers (0, 7 and 14 cm) with the 7 cm sample representing the drip line under a protective wedge designed to keep water out of the joints. Samples were collected at two depths representing groundline and the depth of the barrier in the soil (7.5 – 13 cm) and directly under the barrier. Soil samples collected after 8 years showed highest contaminant levels close to the barrier and under the wedge dripline. Arsenic levels in some locations close to CCA treated panels exceeded Swedish and Canadian soil guidelines for agricultural use and copper levels were above residential/park guidelines for some locations near ACQ and Tanalith MCB treated panels.
P A Cooper, Y T Ung, M-L Edlund, J Jermer, O Söderström


The Phase Out of CCA in the United States
2002 - IRG/WP 02-50194
In mid-February, 2002 the Administrator of the United States Environmental Protection Agency, Christine Todd Whitman, announced that the US treated wood industry will have until the end of December 2003 to end residential uses for Chromated Copper Arsenate (CCA). Industrial uses of CCA will still be allowed after the December 2003 date. This paper explores the events that led up to the announcement by the US EPA Administrator.
J D Schert


A comparison of the effectiveness of a vacuum oven and a wind tunnel in the accelerated ageing of treated wood by evaporation
1989 - IRG/WP 2334
R J Orsler, G E Holland


Assessment of contamination of soil and water at a CCA treatment plant: A demonstration project
1996 - IRG/WP 96-50067
Soil, sludge, dust and water samples were collected at a copper/chromium/arsenic wood preservation plant. Contamination of soil, sludge, dust and surface water with copper, chromium and arsenic was detected. Levels of contamination were sufficiently high to require remediation. Contamination originated from preservative solution dripping from recently treated wood. Migration of contaminants was via surface water run-off; poor housekeeping and operational procedures; forklift movements and wind-blown dust.
P N Durrant, D C R Sinclair, G M Smith


Biocontrol of Reticulitermes santonensis by entomopathogenic fungi - Improvement of the contamination process
2000 - IRG/WP 00-10359
The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were selected for their potential to control the subterranean termite Reticulitermes santonensis. The research work aims to increase the mortality of termites by improving the contamination process inside a termite colony. The transfer of fungal spores from contaminated termites to a whole colony of termites was thus studied. In a first step, termite workers were contaminated by spores. Then they were introduced in a population of healthy workers at 10%, 25% and 50%. The tests showed that 25% and 50% of initially contaminated termites was sufficient to spread the spores among the healthy termites. The total mortality reached 100% within a few weeks. Experiments were carried out using the two entomopathogenic fungi and different methods of contamination. Results are discussed taking into account the possible development of a bait in the future.
I Le Bayon, D Ansard, C Brunet, S Girardi, I Paulmier


Assessment of wood preservation facilities in Canada
1989 - IRG/WP 3557
This document sets out an assessment procedure for the current status of the wood preservation industry in Canada in relation to the Technical Recommendations (TR) documents for the Design and Operation of Wood Preservation Facilities published by the Government of Canada in April 1988. A questionnaire has been prepared in consultation with industry and the Canadian Institute of Treated Wood. An assessment report (state-of-the-art) will be prepared on the basis of the information provided in these questionnaires and discussions.
G Das, V N P Mathur


Soil contamination at the wood preservation industry: Treatment technologies
2001 - IRG/WP 01-50166-16
The soil is a specific compartment of the biosphere, because it is not only a geochemical sink for contaminants, but it also acts as a natural buffer, controlling the transport of chemical elements and substances to the atmosphere, hydrosphere, and biota. Soil contamination problems are expected at wood preservation sites, particularly at those which use(d) inorganic wood preservatives or creosote. In sites where sap displacement methods were used, as the Boucherie method or the modified Boucherie procedure, spills of preservatives directly on the soil, or serious soil contamination are almost a constant. In sites where only pressure methods took place (Bethell, vacuum/pressure or full-cell process), the expected soil contamination is reduced, comparing with the former methods. However, there are still major areas of concern in a plant, such as: around solution storage tanks, near autoclave treatment site, in storage areas for freshly treated wood, in storage areas for final wood and in storage areas for sludge associated with dissolved salts of Cu, Cr and As. Today, there are detailed manufacturers and statutory Codes of Practice regarding safe handling procedures with recommendations for enclosing drip-dry areas and having dedicated fork lift trucks. There are also accelerated fixation technologies available to prevent the occurrence of handling wood wet with preservative and to speed up the production process. However, there are still many treatment plants operating with high level environmental impact. This paper presents a collection of available data related with the soil contamination problem in Europe, due to the wood preservation industry, as well as it gives examples of soil treatment technologies which have already proved to remediate, or are being tested in the remediation, of soil pollution cases. In the framework of COST E22 - Environmental Optimisation of Wood Protection, Working Group 2 - Impacts, the network Soil Remediation is giving the first steps, and it is our will to include as much information as possible, on the topic here presented. This Symposium is then a privilege space for all, e.g. industries, to show up their interest on the topic.
A B Ribeiro, L M Ottosen


Review of remediation methods of sites contaminated by wood preservatives - testing of filter material for use in permeable barrier technology
1999 - IRG/WP 99-50141
Several treatment methods are currently available for treatment of contaminated sites. Soil and water can be treated by immobilisation, separation or destruction of contaminants. It has been common to use intensive treatment methods starting with soil excavation to reach strict purification goals. However, technical and financial reasons make it difficult to reach the desired treatment criteria. As a result, alternative treatment methods are now being allowed. Less intensive in situ methods are being developed, such as natural attenuation, phytoremediation and permeable barriers. A permeable barrier is a passive treatment method for contaminated groundwater. A study was conducted to test various barrier materials for filtering creosote contaminated groundwater. Peat, compost, bark, sewage sludge and sewage sludge pellets were tested out for sorption of phenol, 2-methylphenol and 2,4-dimethylphenol. Peat and compost showed best sorption efficiency. Peat and compost were mixed with sand in various fractions to see if sand can be used to improve hydraulic properties of the filter material.
G Rasmussen, H Iversen, S Andersen


A contribution to the adsorption/desorption behaviour of zinc-hexa-fluoro-silicate in different soils
1995 - IRG/WP 95-50056
The estimation of a possible endangering of the groundwater through wood preservatives and thereof deriving measures for the avoidance of secondary damages require among others exact knowledge concerning the behaviour of wood preservative compounds in the soil matrix. Adsorption and desorption behaviour were determined at four soils of different characteristics, which were brought in contact with aqueous solutions of zinc-hexa-fluoro-silicate. For the respective experiments four concentrations were prepared containing 10, 50, 100 and 250 ppm zinc ions. Water of p.a. quality served as reference. As to be expected the soils in question behaved different: the adsorption of inserted ions increased with increasing clay content of the soil. On the other hand significant differences exist also with respect to the adsorption behaviour of the zinc cation in relation to the hexa-fluoro-silicate anion. Within the concentration interval investigated, the same soil adsorbed approximately the same proportional zinc quantity. However, when increasing the hexa-fluoro-silicate-ion concentration a proportional decrease concerning the degree of adsorption was observed. The results show that it is not possible to conclude from partial results achieved with individual preservative compounds to the overall system "wood preservative"-soil and that further investigations are necessary for an inclusive description of the problem.
E Melcher, R-D Peek


The influence of soil pH on leaching of CCA elements from pressure-treated Eucalyptus saligna sapwood: environmental implication
2003 - IRG/WP 03-50203
Evidence is accumulating as to poor distribution and fixation of CCA in tropical hardwoods, and there is therefore a necessity to investigate the permanency of CCA in tropical hardwoods. The relationship between soil pH and leaching of Cu, Cr and As from CCA pressure-treated sapwood of Kenyan-grown Eucalyptus saligna was tested under laboratory conditions. Small sapwood samples were pressure-treated with 6% CCA-C (oxide type) to a retention of 25.4 Kg/m3, and leached with mild agitation in soil-extract water representative of soil pH 3.5, 4.5, 5.0, 7.5, 8.5, and in tap water (pH 6.8), for 3, 6, 9, 12, 15 and 18 days under controlled laboratory conditions. The results revealed that leaching of Cu, Cr and As was generally high under acidic conditions, low under alkaline situations and lowest at neutral pH. After leaching for 18 days at pH 3.5, average extraction of Cu, Cr and As was respectively 60.8 ppm, 51.3 ppm and 53.8 ppm. Leaching at pH 6.8 extracted low average amounts of Cu, Cr and As, being 0.15 ppm, 0.25 ppm and 0.42 ppm respectively. At pH 8.5 losses were Cu: 1.9 ppm, Cr: 2.4 ppm and As: 1.4 ppm. The patterns of leaching of the elements were irregular in relation to pH and the order established after 18 days of leaching was Cu>As>Cr at pH 3.5, As>Cr>Cu at pH 6.8 and Cr>Cu>As at pH 8.5. Apart from the influence of pH alone, the chemical, physical and microbiological properties of the soil-extract water used may also have influenced leaching. The results indicate that CCA-treated E. saligna used in ground contact, especially in acidic soils, may lose significant amounts of Cu, Cr and As to the environment. The environmental risks that the large number of CCA-treated hardwood poles and posts used in tropical soils represent raise the question as to whether CCA should remain the preferred wood preservative for tropical hardwoods, especially the eucalypts.
R Venkatasamy, D N Okwara


Dimension of lysimeters and the evaluation of the migration of wood preservative components in soil
1996 - IRG/WP 96-50065
In the past, investigations concerning the migration behaviour of wood preservatives were made to a minor extent and no uniform methods of test exist. The migration behaviour of CFB was determined using 5 lysimeters of different dimension. The results of the migration and distribution of the anions in the soil showed considerable differences between both ions. Approximately the whole quantity of chromium was found in the percolate independent from the lysimeter used. In contrast the fluoride ions were adsorbed almost completely at the soil. The fluoride was bound mainly in the top zone, the chromium ions were apportioned over the total column. From the concentrations of fluorine and chromium in the column or soil solution it can be concluded, that in a case of accident a contamination of the soil by fluoride and of the groundwater by chromate is to be expected. The dimension of the lysimeter seems to be of secondary importance and some parameter proved to be advantageous. - Diameter of the lysimeter at least 5 cm - Filling height of the soil in the lysimeter at least 20 cm; preferably 30 cm - Glass fibre filters as a boundary layer between the soil and the bottom of the column - Use of transparent material for the lysimeter, like polymethylpenten (PMP; TPX).
E Melcher, R-D Peek


Délavabilité de bois ronds traités avec un sel CCA dans des conditions réelles de stockage. Incidence pratique de la fixation accélérée par étuvage. Impact effectif sur l'environnement
1993 - IRG/WP 93-50001-23
Un essai de terrain a été organisé pour mesurer concrètement, dans des conditions aussi proches que possibles des conditions réelles de terrain, les pertes effectives en produit de traitement lorsque le bois traité est soumis à des intempéries. L'essai a été conduit sur des bois ronds (poteaux), traités en autoclave par procédé Bethell avec un sel CCA de type C, avec comme finalité l'évaluation de la nature et des quantités de composés délavés en pratique, pour évaluer ainsi leur impact réel sur l'environnement au niveau du site de traitement. Compte-tenu des propriétés fixantes de ce type de produit, il était interessant d'identifier ces pertes à différents stades de la fixation, ainsi qu'après fixation compléte. Utilisant également les divers travaux et constats disponibles à ce jour sur les possibilités d'accélérer la fixation par l'étuvage, nous avons voulu observer et quantifier cette amélioration dans les mêmes conditions de terrain. Cet essai a été organisé et exécuté conjointement par le CTBA et la société FRANE BOIS IMPREGNES. Il conduit à 3 constatations principales: - Les pertes pratiques sont quantitativement nettement moins importantes que celles obtenues à partir des méthodes et échantillons de bois utilisés en laboratoire. - A l'issue et surtout au cours de la fixation les divers métaux se comportent de façon très différente, et on peut penser que la nature de la formulation a une importance notable sur ce comportement, même si dans tous les cas les quantités concrètement délavées restent faibles. - L'éuvage en sortie de traitement et dans des conditions adaptées permet d'obtenir spontanément, un résultat analogue à celui obtenu par un cycle de fixation traditionnel.
M Rayzal, F Larroze


A comparison of the migration behaviour in soil of different waterborne wood preservatives and their leachates
1997 - IRG/WP 97-50091
Lysimeter tests were carried out on water-soluble wood preservatives and on wood preservative components leached out of impregnated wood. The purpose of these tests was to determine the extent to which the migration behaviour of environmentally relevant ions in the soil is influenced under comparable conditions. The results clearly show that the groundwater is especially at risk when wood preservatives are allowed to penetrate the soil unhindered (worst case). Anions, such as chromates for example, are a particular risk as they are scarcely adsorbed by the ground matrix and can therefore enter the groundwater supply very quickly. On the other hand, copper, for example, is adsorbed so firmly by the soil that only negligible concentrations are found in the eluate. Its risk to the groundwater can therefore be ruled out. The lysimeters were filled with leachates containing preservatives from treated wood. The copper, zinc, chromium and fluorine ions were mainly analysed in the top layers of soil, thus indicating that in practice "only" regional soil contamination is to be expected. On the other hand, the concentrations of these ions found in the eluate are of the size if those which occur naturally, as was expected. The following ranging can be concluded for the tested water-soluble wood preservatives and their leachates containing preservatives from treated wood with regard to a possible risk to soil water or groundwater: wood preservative >> impregnated wood (wood preservative not yet fixed) > impregnated wood (wood preservative fixed).
E Melcher, R-D Peek


The fate of salt preservatives in facility yard soils and decontamination of soils and drainage waters
1993 - IRG/WP 93-50001-25
Extensive studies during the past 10 to 15 years revealed that noticeable amounts of preservative components may be released in the environment by dripping off or by rain prior to fixation unless adequate precautions are taken. Therefore, soil and groundwater contamination especially from chromium-VI compounds but also from other inorganic and organic constituents exist in impregnation plants, possibly endangering the soil and groundwater ecosystem. The actual risk potential originating from chromium-containing wood preservatives in a practical situation are to be studied in the frame of a comprehensive research programme sponsored by the German Ministry of Research and Technology (BMFT). Accompanying laboratory investigations are performed with the aim of assessing the various types of water-soluble wood preservatives with respect to whether or possibly which compounds remain mobile und thus bio-available in the soil. Special attention is drawn to the question as to which effective constituents are adsorbed to soil particles depending on the mineralogical-geological composition of the soil, and at what situation the retention capacity for effective components of different soils would be exceeded. The results of the pilot study and of parallel running laboratory tests serve as a basis of deterioration analyses for grading and assessing the endangering potential in the ecosystem and shall provide a basis for the choice of adequate remedial concepts and measures to avoid such environmental impacts.
R-D Peek, H Klipp, K Brandt


Do CCA treated support stakes cause increased arsenic level in crops?
2003 - IRG/WP 03-50204
Trial of using CCA-C treated eucalypts stakes for supporting banana plants in Guangdong Province, China, began in 1998 and later it was expanded as a demonstration program of a joint International Tropical Timber Organization–Chinese Government timber preservation project in 2000. The greatest concern was whether the crop would be contaminated by the preservatives, arsenic in particular. Data from four years tracking analysis of bananas collected from the demonstration plots indicated that the arsenic levels were not significantly higher than the levels found in plants supported by untreated stakes. The arsenic content in bananas supported by preservative treated stakes was well below the level specified in food standards of China. Similar results were obtained from a trial of tomatoes and garden peas supported with treated eucalypts and round bamboo posts in pottery pots.
Li Zhaobang, Su Haitao, Liang Linqing


Leaching of arsenic, copper and chrome from preservative-treated timber in playground equipment
1984 - IRG/WP 3149
Samples were taken from CCA-treated timber in sand play boxes and other play ground equipment. Sand was also sampled. Sand and wood samples were analysed for copper, chrome and arsenic by AAS. About 20-25% of the arsenic had leached from the timber after 2-4 year's exposure in the playgrounds. Very little of the copper and chrome had been leached. Sand collected in the close vicinity of the treated timber contained at maximum 12.9 mg and on average 4-6 mg As/kg. Natural soils may contain from 1 to 40 mg As/kg. There is little risk for children to be poisoned by eating the As-contaminated playground send, since this would require consumption of at least 10-30 kg sand on a single occasion.
B Henningsson, B Carlsson


Remediation of wood treatment sites in Finland
1999 - IRG/WP 99-50139
Finnish legislation in connection with soil contamination are firstly waste management legislation and secondly public health legislation and water legislation. There is no separate legislation concerning soil protection or remediation. The Ministry of the Environment has published a proposal for official contaminant guideline values to be used both as criteria for contamination and clean-up target values. Today whether a site is contaminated or not is evaluated according to provisional guideline values set by the Ministry in 1996. In the legislation the liability for remediation has been defined according to the "Polluter pays" principle. In case the polluter is not found or is not able to take care of the remediation, the municipality is responsible for the implementation of remediation, in some cases with the help of central government funding. In most of the cases remedial works have to have a licence from one of the 13 Regional Environment centers. The Ministry of the Environment set up a special nation wide project to evaluate the problems related to soil contamination. The project (SAMASE) published its report in the end of 1994. Report includes a list of potentially contaminated sites and as summary the number of suspected sites is presented. In 1994 the estimate of the number of sites to be remediated for the next 20 years was 1.177. Remediation activity of contaminated sites had long been fairly low, and in the early 901es the number of clean-up projects was 10 - 20. Remediation activity was stronly increased by the SAMASE-project and today the number of clean-up projects is about 150 annually.
S Salonen


The growth and metal content of plants grown in soil contaminated by a copper/chrome/arsenic wood preservative
1977 - IRG/WP 3110
Salts of copper, chromium and arsenic are used together in water soluble formulations for the preservation of wood against insect and fungal attack. Copper/chrome/arsenic (CCA) preservatives are of proven efficacy and, used correctly, ensure a useful service life for timber for 30 years or more with little, if any, attendant threat to the environment from the treated wood itself. The preservative treatment site can, however, provide a point of entry for the preservative into the general environment by way of spills and leaks of the treating fluid and run off from treated wood, with resultant contamination of the surrounding soil. The possible effects of the CCA salts on plant growth and metals uptake are the subject of this paper. In a series of greenhouse pot experiments the effects of varying concentrations of CCA in soil on the germination, growth and cropping of beans, carrots and tomatoes was studied. Crops produced by the plants were analysed for their copper, chromium and arsenic contents. Additionally, grasses were grown to assess possible land reclamation difficulties. It was found that soil having a combined copper, chromium and arsenic concentration of approximately 7000 ppm completely inhibited the growth of all the plants tested, while certain concentrations below this inhibited or retarded growth to some degree. Carrots grown in soil containing approximately 1000 ppm Cu, Cr, As (200 ppm As) produced crops containing nearly twice the current recommended limit for arsenic in food. Relating the levels of CCA used in the experimentally dosed soil with the amounts found in soil samples taken from preservative treatment sites, it is apparent that many contaminated areas would not support plant life. Less heavily contaminated soil will support growth and may give rise to crops with arsenic levels higher than those deemed to be safe.
C Grant, A J Dobbs


Plant uptake of CCA components from contaminated soil
1995 - IRG/WP 95-50043
The above ground portions of lettuce and rye grass grown in CCA contaminated soil collected at the base of CCA-C treated poles in service did not absorb appreciable amounts of copper, chromium and arsenic, even at soil concentrations above the recommended levels for soil remediation for agricultural uses. At high soil arsenic levels whole radish plants absorbed more As, but not the other elements. The uptake of all elements by the root portion of rye grass increased with increased soil contaminant levels. The Cr, Cu and As content of lettuce roots was more than double that of the leaves and for copper appeared to increase with increasing soil concentration. Natural growing horsetails (Equisetum) accumulated all three elements in proportion to the soil concentration; cattails did not accumulate the elements appreciably and grass growing close to CCA treated poles had relatively higher concentrations of Cr and As compared to other plants.
P A Cooper, E Jasonek, J-P Aucoin


Inorganic preservative levels in soil under treated wood decks after 8 years natural exposure in Borås, Sweden
2005 - IRG/WP 05-50233
Inorganic preservative components (Cu, Cr and As) were measured to a depth of 150 mm under deck structures made with Scots pine lumber treated with several different wood preservatives and installed in Borås Sweden 8 years ago. Higher contaminant levels were observed mainly under the drip lines and in the top 50 mm of soil. Under CCA treated decks, soil arsenic concentrations increased from background levels of about 3.5 mg/kg to 6-15 mg/kg in this zone. Copper and chromium levels were only slightly elevated above backgrounds of about 10 mg/kg and 3 mg/kg respectively. Copper levels were also only slightly elevated under decks treated with Tanalith E, Impralit KDS and Wolmanit CX-S. The Wolmanit CX-8 treated wood had concentrations averaging about 45 mg/kg in the top soil layer under the drip line while the Kemwood ACQ treated deck had concentrations above 100 mg/g in this zone.
P A Cooper, Y T Ung, M-L Edlund, J Jermer


Fluoride and chromium concentrations in soil adjacent to remedially treated distribution poles
1996 - IRG/WP 96-50066
Soils adjacent to Rentex treated 'on-line' distribution poles were analysed for total fluoride and chromium content for comparison with background values of these elements. Soil samples 6 cm and 25 cm downslope of selected poles were recovered at 1 week, 1 month, 6 and 12 months after treatment. Background soil samples were taken 50 m from the poles at sampling times. Fourteen poles were selected for use on the basis of groundline moisture content. Results indicated significant fluoride and chromium soil contamination adjacent to the treated poles. Preservative loss appeared to increase up to 6 months after treatment and was associated with pole moisture content. Results are discussed in terms of the relationship between preservative efficacy and environmental impact.
D C R Sinclair, G M Smith, A Bruce, H J Staines, P Durrant


PCP in aquatic environments arising from historic contamination at wood processing and preservation sites
1995 - IRG/WP 95-50040-14
Three different studies are reported that assess the impacts of Pentachlorophenol (PCP) in aquatic environments arising from its historic use at sawmilling and wood preservation sites. These studies involved New Zealand wood processing facilities, and collectively they aimed to measure the transport of PCP from sawmill sites into the aquatic environment, determine the background environmental concentration of PCP in isolated lakes of New Zealand, and assess the relative contribution of PCP from different potential sources, such as sawmills, urban areas and agricultural catchments. The PCP concentrations in water, sediment and biota from a lake catchment, near a major wood processing site, indicated that low level contamination had occurred. PCP levels in lake sediments and freshwater mussels were elevated compared to New Zealand remote lake sites but similar to comparable locations reported in the international literature. Water concentrations of PCP in the lake were less than the most stringent international water quality guidelines for the protection of aquatic life. Water and sediment PCP concentrations in streams within the catchment, isolated from point sources, were less than the detection limit. The PCP concentration found in sediments ( £ 1.3 ng.g-1 DW) from the remote lakes, reflects a New Zealand background concentration. The source of PCP in remote lake sites is unknown, though it is unlikely to be directly from the sawmilling industry. Although the historic use of PCP by the sawmilling industry appears to have caused localised contamination near areas of high use, the current evidence suggests that it has not lead to widespread contamination of New Zealand aquatic environments.
J S Gifford, P N McFarlane, M C Judd, S M Anderson


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