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Abstract There is increasing concern about the use of chromated copper arsenate (CCA) treated timber due to the possible leaching of toxic metals or metalloids. CCA-treated timber waste are currently stockpiled across Australia with limited information about their risks to the environment or human health. In this study, the treatment and utilisation of CCA-treated timber waste as garden mulch, garden retaining walls, and soil additive were investigated. Iron materials were used as immobilising agents. The bioavailability of Cr, Cu and As to Spinacia oleracea from CCA-treated timber, before and after treatment, was determined in the context of human health risk assessment. The results showed that the iron-based treatments resulted in significant decreases in the concentrations of Cu and As in spinach grown in CCA-treated timber in soil. Analyses of CCA derived Cu and As in spinach showed that they accumulated in the roots rather than in the leaves. The risks of toxicity to humans varied for different utilisation scenarios and the immobilisation amendments were shown to reduce carcinogenic and non-carcinogenic risks. The information obtained in this study can inform development of utilisation options for CCA-treated timber wastes. Graphical abstract Image 1 Highlights • Iron materials reduced leachability, bioavailability and risks for CCA metal(loid). • As, Cr mainly accumulated in root of spinach rather than leaves. • Most As and Cr present in leaves are As(V) (50–90%) and Cr (III) (50–100%). • Treated mulch showed acceptable low carcinogenic and non-carcinogenic risks. [ABSTRACT FROM AUTHOR]

Soil contamination enters aquatic ecosystems affecting sediment quality. The region studied is the Taquari River, Brazil, close to a site contaminated by wood preservatives, with a runoff route into the river. The first stage of the remediation process (In this article, the terms intervention and remediation have been used with slightly different meanings. We consider intervention to be the first phase of the remediation process, which aims to remove active sources) was an intervention to remove the main active sources. The Salmonella/microsome assay and polycyclic aromatic hydrocarbons (PAHs) were used to assess sediment quality in organic extracts during different intervention phases. The strains used were TA98, TA97a, and TA100 with and without S9mix (±S9). The results indicated the presence of pro‐mutagens at site Ta010 (closest to the contaminated site) in all samplings, and the highest result occurred before intervention for TA100 + S9 (1,672 ± 215.9 rev/g). These values decreased during (83 ± 23.6 rev/g) and after this process (403 ± 105.9 rev/g), although the PAHs concentrations increased. Samples from this site presented PAHs with a carcinogenic potential during the assessed periods. After intervention, Ta006 (4 km downstream from Ta010) showed the most significant mutagenesis for TA100 + S9 (764 ± 230.2 rev/g) and, although the total PAHs values were lower, the species considered carcinogenic had higher concentrations. Mutagenesis predicted values of PAHs confirmed that carcinogenic species were predominantly detected by TA100, and the other PAHs by TA97a strains. Marked contaminant release to the river was observed, mainly in Ta010 at different periods. Mutagenicity and PAHs values in an internal stream, upstream from Ta010, showed a dispersion route of these agents. Thus, contamination in Ta010 and possible contribution to Ta006, after intervention, provides a warning regarding environmental quality in the region. Environ. Mol. Mutagen. 59:625–638, 2018. © 2018 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The widespread use of chlorinated phenols (CPs) as a wood preservative has led to numerous contaminated sawmill sites. However, it remains challenging to assess the extent of in situ degradation of CPs. We evaluated the use of compound-specific chlorine and carbon isotope analysis (Cl- and C-CSIA) to assess CP biotransformation. In a laboratory system, we measured isotopic fractionation during oxidative 2,4,6- trichlorophenol dechlorination by representative soil enzymes (C. fumago chloroperoxidase, horseradish peroxidase, and laccase from T. versicolor). Using a mathematical model, the validity of the Rayleigh approach to evaluate apparent kinetic isotope effects (AKIE) was confirmed. A small but significant Cl-AKIE of 1.0022 ± 0.0006 was observed for all three enzymes, consistent with a reaction pathway via a cationic radical species. For carbon, a slight inverse isotope effect was observed (C-AKIE = 0.9945 ± 0.0019). This fractionation behavior is clearly distinguishable from reported reductive dechlorination mechanisms. Based on these results we then assessed degradation and apportioned different types of technical CP mixtures used at two former sawmill sites. To our knowledge, this is the first study that makes use of two-element CSIA to study sources and transformation of CPs in the environment. [ABSTRACT FROM AUTHOR]

Wood (timber) is an important raw material for various purposes, and having biological composition it is susceptible to deterioration by various agents. The history of wood protection by impregnation with synthetic chemicals is almost two hundred years old. However, the ever-increasing public concern and the new environmental regulations on the use of chemicals have created the need for the development and the use of alternative methods for wood protection. Biological wood protection by antagonistic microbes alone or in combination with (bio)chemicals, is one of the most promising ways for the environmentally sound wood protection. The most effective biocontrol antagonists belong to genera Trichoderma, Gliocladium, Bacillus, Pseudomonas and Streptomyces. They compete for an ecological niche by consuming available nutrients as well as by secreting a spectrum of biochemicals effective against various fungal pathogens. The biochemicals include cell wall-degrading enzymes, siderophores, chelating iron and a wide variety of volatile and non-volatile antibiotics. In this review, the nature and the function of the antagonistic microbes in wood protection are discussed. [Copyright &y& Elsevier]

Okara, an organic waste product obtained from soy milk production, was used with copper chloride or sodium borate to formulate new wood preservatives as a substitute for expensive wood preservatives, such as copper-azole-based preservatives and ammoniacal copper quaternary. Before formulating the preservatives, okara was hydrolyzed by enzymes (cellulase, pectinase, and protease) to augment penetration and fix the biocide salts of the preservatives into wood blocks. The preservatives were injected into wood blocks by vacuum pressure to measure the treatability of the preservatives. The treated wood blocks were placed in hot water for 3 d to measure leachability. The treatability and leachability of the preservatives were affected by the type and loading amount of enzymes and the addition of sodium borate into okara-based wood preservative formulations. The treatability and leachability of the preservatives formulated with copper chloride and okara hydrolysates were 63.38 and 3.15%, and those of the preservatives with copper chloride, okara hydrolysates, and sodium borate were 61.47 and 3.32%, respectively. Despite the hot water leaching, wood blocks treated with preservatives formulated with 2% cellulase, pectinase, and protease hydrolyzed okara, CuCl, and sodium borate showed only 1.98% average weight loss against Fomitopsis palustris over 12 weeks. Microscopic observation revealed how okara-based preservatives work in wood blocks. Okara has potential as a raw material for cost-effective and environmentally friendly wood preservatives. Environ. Toxicol. Chem. 2011; 30:1297-1305. © 2011 SETAC [ABSTRACT FROM AUTHOR]

The efficiency of semitransparent penetrating stains to reduce leaching of wood preservative components was evaluated. Five commercial wood deck finishes were applied to untreated and chromated copper arsenate (CCA), alkaline copper quat (ACQ), and copper azole (CA) treated wood, and leachates were collected and analyzed during 3 years of natural weathering exposure in Toronto, Canada. All stains evaluated effectively reduced the cumulative leaching of all inorganic preservative components by about 60% on average. Although most coatings showed significant film degradation starting around 12 months, the reduced leaching persisted even after 3 years. This suggests that temporary protection of wood with a coating during the early stages of use resulted in long-term reduction in preservative leaching potential. A two-week screening leaching test was able to predict the long-term leaching performance of different coatings reasonably well. Cured coating glass transition temperature (Tg) and liquid coating viscosity were the most important variables affecting a leaching prediction model. To effectively reduce leaching of preservative components from treated wood, coatings should have Tg low enough to withstand stresses caused by freezing in winter and have adequate viscosity to form a barrier film layer on the wood surface. [ABSTRACT FROM AUTHOR]

Children may be exposed to arsenic during contact with structures treated with chromated copper arsenate (CCA). A high frequency of hand-to-mouth activity may increase their risk of ingesting arsenic. Previous work showed that arsenic concentrations in the hand-wash samples of children playing on CCA playgrounds were four times higher than those playing on non-CCA playgrounds. It is not clear whether playing on CCA playgrounds results in elevated overall exposure to arsenic. The objective of this study was to perform arsenic biomonitoring in children to determine whether playing on CCA-treated playgrounds substantially contributes to their overall exposure to arsenic. One hundred and twenty five saliva samples from 61 children and 101 urine samples from 45 children were collected after children played on 8 CCA and 8 non-CCA playgrounds. Arsenic speciation analysis was conducted using high performance liquid chromatography combined with inductively coupled plasma mass spectrometry. The arsenic species detected in the urine and saliva samples from children playing on CCA and non-CCA playgrounds were similar. Dimethylarsinic acid and arsenobetaine were the main arsenic species found in urine samples. The sum of inorganic trivalent and pentavalent arsenic, monomethylarsonic acid, and dimethylarsinic acid in urine was 15 ± 28 μg/L in the CCA group and 12 ± 23 μg/L in the non-CCA group (p = 0.60). The sum of these species in saliva was 1.1 ± 2.1 μg/L in the CCA group and 1.4 ± 1.1 μg/L in the non-CCA group (p = 0.32). These results show that there is no significant difference in the concentration or speciation of arsenic between the samples from children playing on CCA and non-CCA playgrounds. Contact with CCA playgrounds is not likely to significantly contribute to the overall arsenic exposure in children; other sources such as dietary arsenic may be a main contributor to their overall exposure. [ABSTRACT FROM AUTHOR]

Earlier studies documented the loss of wood preservatives from new wood. The objective of this study was to evaluate losses from weathered treated wood under field conditions by collecting rainfall leachate from 5 different wood types, all with a surface area of 0.21 m2. Wood samples included weathered chromate copper arsenate (CCA) treated wood at low (2.7 kg/m3), medium (4.8 kg/m3) and high (35.4 kg/m3) retention levels, new alkaline copper quat (ACQ) treated wood (1.1 kg/m3 as CuO) and new untreated wood. Arsenic was found to leach at a higher rate (100 mg in 1 year for low retention) than chromium and copper (<40 mg) in all CCA-treated wood samples. Copper leached at the highest rate from the ACQ sample (670 mg). Overall results suggest that metals' leaching is a continuous process driven by rainfall, and that the mechanism of release from the wood matrix changes as wood weathers. [Copyright &y& Elsevier]

Two soils with similar contamination levels from wood preservatives containing Chromium (Cr), Copper (Cu) and Arsenic (As) (CCA), were assessed for their general toxicity and genotoxicity. A set of water-based extraction methods, including pressurized liquid extraction (PLE), and batch leaching in milli-Q water and a weak CaCl2-solution, was used to produce soil extracts containing available fractions of contaminants. In addition, to obtain indications of the contaminants'' bioavailability and toxic potential the genotoxicity of the extracts was estimated by testing their ability to inhibit the growth of wildtype Chinese hamster ovary cells (CHO-cells) and three genetically modified pheno-types that are deficient in different DNA-repair mechanisms. Total extractable arsenic concentrations in the extracts were comparable between the sites. However, the genotoxic potential was clearly higher in soil R extracts. The differences in genotoxic responses were related to differences in inorganic arsenic speciation. The ratio of trivalent arsenic (AsIII) to pentavalent arsenic (AsV) was higher in all soil extracts from soil R, regardless of the leaching method used. The results of the various combinations of soil extraction techniques and assays using the CHO-cell lines reflected important differences in arsenic speciation in the two soils and possible synergistic effects in CCA-related exposure. They also indicate that speciation and combinatory effects are factors that should be taken into account when assessing risks at former wood impregnation sites contaminated by CCA-agents. [Copyright &y& Elsevier]

Abstract: As a result of wood treatment, and the recent banning of the copper, chromium, and arsenic (CCA) treated wood for residential use many CCA treatment facilities have been abandoned or being closed. Soil contamination resulting from CCA is common at these sites. In this study, the feasibility of electrokinetic technique to remove CCA from contaminated soil was investigated. To better understand the ionic mobility within the soil and to detect the generation and advancement of acid front, sampling ports were provided along the longitudinal axis of a test cell. To determine the effect of varying current, three tests were performed at different current densities of 5.9, 2.9, and 1.5mA/cm2 for a period of 15 days. The initial concentrations of copper, chromium, and arsenic in the soil were 4800, 3100, and 5200mg/kg, respectively. Dilute nitric acid was used as an amendment to neutralize the hydroxyl ions produced at the cathode. Experiments resulted in removal efficiencies as high as 65% for copper, 72% for chromium, and 77% for arsenic. The results also indicated that the advancement of acid front favored desorption of metals from the soil and the metals were mobilized either as free cations or metal complexes. Chromium that was in its +6 valence state was transported as anion prior to its reduction. However, once the chromium was reduced to chromium(III) its transport direction reversed with transport being favored towards the cathode. [Copyright &y& Elsevier]

Kymijoki, the fourth largest river in Finland, has been heavily polluted by pulp mill effluents as well as the chemical industry. Up to 24000ton of wood preservative, chlorophenol known as Ky-5, was manufactured in the upper reaches of the river, an unknown amount of which was discharged into the river between 1940 and 1984. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) occurred as impurities in the final Ky-5 product. The PCDD/F concentrations and burden in the river sediments were studied and the transport of PCDD/Fs from contaminated sites downstream and into the Gulf of Finland in the Baltic Sea was estimated. More than 190 sediment cores were sampled to estimate the volume of contaminated sediments and the total PCDD/F burden. The transport of PCDD/Fs was estimated using sediment traps placed at several sites. The survey revealed that sediments in the river were heavily polluted by PCDD/Fs, the main toxic congener being 1,2,3,4,6,7,8-heptachlorodibenzofuran, a major contaminant in the Ky-5 product. The mean total concentration at the most polluted river site downstream from the main source was 42000μgkg−1 d.w. (106μg I-TEQkg−1). The elevated concentrations in the coastal region and the present estimated transport from the River Kymijoki confirm earlier assessments that the river is a major source of PCDD/F for the Gulf of Finland. [Copyright &y& Elsevier]

The aim of this study was to determine the efficacy of selected basidiomycetes in the removing of polycyclic aromatic hydrocarbons (PAH) from the creosote-contaminated soil. Fungi Pleurotus ostreatus and Irpex lacteus were supplemented with creosote-contaminated (50–200mgkg−1 PAH) soil originating from a wood-preserving plant and incubated at 15°C for 120d. Either fungus degraded PAH with 4–6 aromatic rings more efficiently than the microbial community present initially in the soil. PAH removal was higher in P. ostreatus treatments (55–67%) than in I. lacteus treatments (27–36%) in general. P. ostreatus (respectively, I. lacteus) removed 86–96% (47–59%) of 2-rings PAH, 63–72% (33–45%) of 3-rings PAH, 32–49% (9–14%) of 4-rings PAH and 31–38% (11–13%) of 5–6-rings PAH. MIS (Microbial Identification System) Sherlock analysis of the bacterial community determined the presence of dominant Gram-negative bacteria (G−) Pseudomonas in the inoculated soil before the application of fungi. Complex soil microbial community was characterized by phospholipid fatty acids analysis followed by GC–MS/MS. Either fungus induced the decrease of bacterial biomass (G− bacteria in particular), but the soil microbial community was influenced by P. ostreatus in a different way than by I. lacteus. The bacterial community was stressed more by the presence of I. lacteus than P. ostreatus (as proved by the ratio of the fungal/bacterial markers and by the ratio of trans/cis mono-unsaturated fatty acids). Moreover, P. ostreatus stimulated the growth of Gram-positive bacteria (G+), especially actinobacteria and these results indicate the potential of the positive synergistic interaction of this fungus and actinobacteria in creosote biodegradation. [Copyright &y& Elsevier]

Abstract: In order to better understand the fate of polychloro dibenzo-p-dioxins and furans (PCDD/Fs) in soils around pentachlorophenol (PCP) treated poles, a model was developed to assess the influence of wood-preserving oil and PCP on the vertical migration of octachloro-dibenzo-p-dioxin (OCDD). Simulations were performed for three soil types: sand, clay and organic. OCDD fate was modeled in the absence of co-contaminant and in the presence of oil with or without 5% (w/w) PCP. A variance propagation study was conducted to evaluate the model sensitivity to a small variation in input parameters, to determine the uncertainty on the migration depth modeled for each soil, and to understand the variability of this migration observed between different soil types. The model predicts a different OCDD fate depending on the soil type with a significant migration in the case of sand and an absence of migration in the case of organic soil. No migration is predicted in the absence of co-contaminants and a migration depth of 7–600cm is predicted in the presence of oil (with and without PCP). Model sensitivity also depends on the soil type: the predicted OCDD migration depth is, respectively, 22cm±10cm for organic soils, 71cm±20cm for clay and 566cm±200cm for sand after 60 days of emissions from a class 3, 12.2m long pole. Even if the input parameters have a significant uncertainty due to the lack of available data, the model results seem reliable as a first approximation to screen an eventual PCDD/F migration. [Copyright &y& Elsevier]

Abstract: Wood preserved with chromated copper arsenate (CCA) and alkaline copper quaternary (ACQ) was mixed with artificial rainwater, to generate leachates containing As, Cr and Cu. Then, leachates were applied to two soils at rates of 13–169mg Askg−1 soil (dry weight basis), 12–151mg Crkg−1 and 10–216mg Cukg−1. Metal bioavailability was evaluated after 28 days using the earthworm Eisenia fetida (Savigny). Metal concentrations in earthworm tissue ranged from negligible to 80mg Askg−1 (dry weight basis), 89mg Crkg−1 and 90mgCukg−1, which appeared to be non-lethal to E. fetida. There was less Cu available to earthworms in the Courval soil (pH 7.8) than the Châteauguay soil (pH 6.8), but earthworm growth and reproduction were not affected by exposure to Cu from ACQ-treated wood. In contrast, earthworms exposed to As, Cr and Cu from the CCA-treated wood gained weight more quickly in the Courval soil (1.3–21mgg−1 initial biomass days) than in the Châteauguay soil (0.2–7.8mgg−1 day−1), but fewer than 20% of the cocoons deposited by the faster-growing earthworms hatched by the end of the 56 days ecotoxicology test. It appeared that E. fetida can allocate more energy to growth than reproduction, delaying cocoon development and hatching in some situations. Further information is needed on the soil factors that may induce such behavior, as it can affect the interpretation of results from the earthworm ecotoxicology test. [Copyright &y& Elsevier]

A wood treatment facility operating in southern Alabama released dioxins and other hazardous substances into the surrounding community over a period of approximately 35 years. The facility used a variety of chemical insecticides including pentachlorophenol (PCP), chromated copper arsenate (CCA), and creosote (which contains polycyclic aromatic hydrocarbons (PAHs)) to treat wood. The health risks associated with the released contaminants are numerous and significant. To evaluate the historic exposure to the contaminants from the facility, blood samples and health surveys were collected from 21 current and past residents of the adjacent, isolated community and analyzed for concentrations of polychlorinated dibenzo-p-dioxins (dioxins) and polychlorinated dibenzofurans (furans). In addition, attic dust sampling was performed in 11 buildings located within a 1-mile radius of the former wood treatment facility. The average total dioxin toxic equivalent (TEQ) concentration in the residents’ blood samples was 36.6pg/g lipids. In the attic dust, the average total dioxin TEQ concentration, benzo[a]pyrene (PAH) TEQ concentration, and arsenic concentration were 145ng/kg, 0.98 and 29.8mg/kg, respectively. The concentrations of dioxins measured in the blood samples exceed the 90th percentile total dioxin levels found in the general US adult population. Concentrations of dioxin, arsenic, and PAHs found in the attic samples exceeded the US Environmental Protection Agency (USEPA) Region 4 soil exposure cancer risk preliminary remediation goal (PRG) values. These findings indicate a very significant potential for related health effects in these communities. [Copyright &y& Elsevier]

The remediation of chromated copper arsenate or CCA-treated wood is a challenging problem in many countries. In a wet remediation, the recycling of the washing solutions is the key step for a successful process. Within this goal, owing to its solubility and its toxicity, the removal of arsenic from washing solution is the most difficult process. The efficiency of arsenic removal from As(III) solutions by electrolysis was investigated in view of the recycling of acidic washing solutions usable in the remediation of CCA-treated wood. Electrochemical reduction of As(III) is irreversible and thus difficult to perform at carbon electrodes. However the electrolytic extraction of arsenic can be performed by the concomitant reduction of the cupric cation and arsenite anion. The cathodic deposits obtained by controlled potential electrolysis were analyzed by X-ray diffraction (XRD) and energy dispersive X-ray microanalysis. XRD diffraction data indicated that these deposits were mixtures of copper and copper arsenides Cu3As and Cu5As2. Electrolysis was carried out in an undivided cell with graphite cathode and copper anode, under a controlled nitrogen atmosphere. The evolution of arsine gas AsH3 was not observed under these conditions. [Copyright &y& Elsevier]

The reclamation of resources from wastes, through such activities as recycling various kinds of wastes and finding more ways to use them, is an important part of changing to a sustainable society. It is also important to ensure the safety of products by, for example, removing hazardous substances from recycled items. Wood is a type of demolition waste. The reuse and recycling of wood from demolition have not progressed much. To increase the number of ways of using wood wastes we have examined methods of making carbonized materials from them and using these carbonized materials to control indoor air pollution (Shibano et al., ). Research currently underway on ensuring the safety of recycled items includes investigating the behavior and other characteristics of hazardous substances that are, or may very well be, found in recycled items. It is known that the smoke arising from the process of carbonizing wood wastes is mutagenic. However, such mutagenic components become smoke and separate from carbonized materials, and, especially at temperatures of 800°C and higher, they hardly remain in carbonized materials at all (Nakajima et al., , . In the carbonization of wood wastes containing hazardous metals such as CCA (Cr, Cu, As)-treated wood, substances that readily vaporize separate from the carbonized materials. One cannot expect, however, the same removal effect on metals that vaporize with difficulty, such as Cu, making it likely that they remain in the carbonized material (Takahashi et al., ). To examine methods of removing hazardous metals which may well remain in carbonized wood wastes, we investigated the removal and recovery of copper from charcoal with a high copper content by applying electricity (direct current) to it. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumber treated with chromated copper arsenate (CCA) compounds has been used in residential outdoor wood structures and public playgrounds. The U.S. Environmental Protection Agency (EPA) has conducted a probabilistic assessment of children's exposure to arsenic using the Stochastic Human Exposure and Dose Simulation model for the wood preservative scenario (SHEDS-Wood). The assessment relied on data derived from an experimental study conducted using adult volunteers and designed to result in maximum hand and wipe loadings to estimate the residue-skin transfer efficiency. Recent analyses of arsenic hand-loading data generated by studies of children actively involved in playing on CCA-treated structures indicate that the transfer efficiency coefficient and hand-loading estimates derived from the experimental study significantly overestimate the amount that occurs during actual play. OBJECTIVES: Our goal was to assess the feasibility of using child hand-loading data in the SHEDS-Wood model and their impact on exposure estimates. METHODS: We used data generated by the larger of the studies of children in SHEDS-Wood, instead of the distributions used by U.S. EPA. We compared our estimates of the lifetime average daily dose (LADD) and average daily dose (ADD) with those derived by the U.S. EPA. RESULTS: Our analysis indicates that data from observational studies of children can be used in SHEDS-Wood. Our estimates of the mean (and 95th percentile) LADD and ADD were 27% (10%) and 29% (15%) of the estimates derived by U.S. EPA. CONCLUSION: We recommend that the SHEDS-Woods model use data from studies of children actively playing on playsets to more accurately estimate children's actual exposures to CCA. [ABSTRACT FROM AUTHOR]

Chromated copper arsenate (CCA) is currently the most commonly used wood preservative in Korea. Questions, however, have been raised regarding the potential environmental impacts of metal leaching from CCA-treated wood to soil. Although a number of researchers from other countries have reported that chromium, copper, and arsenic do leach from CCA-treated wood over time, to date few field studies have been performed on those metals in soils adjacent to CCA-treated wood structures in Korea. The present study was conducted to determine the lateral and vertical distributions and accumulation of chromium, copper, and arsenic in soils collected from CCA-treated wood structures. A total of fifty-five composite soil samples were collected from four CCA-treated wood structures of approximately one year in age. The samples were analyzed for physicochemical properties as well as for the total chromium, copper, and arsenic concentrations. The chromium, copper, and arsenic concentrations in soil samples adjacent to the structures were as high as 79. 0, 98. 9, and 128 mg/kg, respectively, compared to background soil samples (48. 2, 26. 9, and 6. 27 mg/kg, respectively). Arsenic was more mobile in soil than chromium and copper. The concentration gradient of arsenic in soil was observed only to the depth of approximately 5 cm in one year of outdoor exposure, whereas chromium and copper apparently remained near the surface (approximately less than 1 cm) after their release. Future efforts should be made to observe seasonal impacts on the release of metals and incorporate metal speciation into determining more detailed mobility and distribution. [Copyright &y& Elsevier]

This article discusses pentachlorophenol (PCP) residues in suspended particulate matter and surface sediments from the Yangtze River watershed in China. According to the authors, the biocide, sodium pentachlorophenol, is used for protection of woods and textiles, but it is a toxic, endocrine disrupting chemical, which is carcinogenic, mutagenic and subject to bioaccumulation. Also, some of the impurities include polychlorinated dibenzo-dioxins and furans. Levels of PCP measured in sediments were below the predicted no-effect concentration in freshwater sediments and below the Netherlands standard. Only one sample of suspended particulate matter exceeded the guidelines.

Experiments were conducted to study CCA-treated wood combustion over a range of temperature and oxygen concentrations with a view to understanding the factors affecting energy and metals recovery from waste treated timber. CCA-treated wood was burned in a furnace at temperatures from 400 to 940°C and oxygen concentrations between 5 and 21%. The ash and condensed volatiles were digested for total concentrations of metals and subjected to leaching tests to determine the stabilized concentrations of metals. Arsenic volatilisation increased with increasing furnace temperature whereas the copper and chromium reported mainly to the ash product. The effect of oxygen concentration was weak although it appeared that more arsenic volatilises at higher oxygen concentrations. However, a larger proportion of the arsenic in the ash generated at lower oxygen concentrations is solubilised during leaching tests, with the result that the concentration of stabilized arsenic in the ash is relatively unaffected by oxygen concentration. [Copyright &y& Elsevier]

This paper aims to show the potential decay resistance of furfurylated wood and investigate possible eco-toxicity of such materials produced. This paper deals with the environmental aspects and durability of furfurylated wood, both laboratory and field tests are included in the investigations. Results from several decay tests, emission analysis studies and ecotox tests are presented. The results show that furfurylated wood is highly decay resistant. Furthermore, no significant increase in eco-toxicity of leaching water was found and degradation through combustion does not release any volatile organic compounds or poly-aromatic hydrocarbons above normal levels for wood combustion. Durability enhancement by furfurylation of wood is not believed to be harmful to the environment. Wood modified with furfuryl alcohol, “furfurylated wood”, is currently being marketed as a non-toxic alternative to traditional preservative treated wood (wood impregnated with biocides). This paper summarises much of the long term exposure of furfurylated wood ever caried out, and present the first eco-tox tests on such material ever done. [ABSTRACT FROM AUTHOR]

Examines the safety of the use of wood treated with chromated copper arsenate (CCA) in the United States. Widespread use of CCA as a wood preservative; Toxicity of arsenic and chromium; Disposal of CCA-treated wood in landfills; Challenge of keeping arsenic and hexavalent chromium out of soil and groundwater; Regulation of the use of CCA by the Environmental Protection Agency.

Investigates the disposal of wood treated with the wood preservative chromated copper arsenate (CCA) in the United States. Prevalence of CCA-treated wood in the country; Growth of the construction industry; Use of recycled CCA-treated wood in concrete composites and in oriented strandboard; Description of sorting techniques; Development of an incineration technique that reduces arsenic emissions.

The article introduces research reported elsewhere in the issue by analytical chemist Chris Le and others on exposure of children to arsenic contained in wood preservatives used in playground lumber. Health risks are reportedly low in comparison to other sources including food. The wood preservative at issue is chromated copper arsenate, where arsenate is said to be the most toxic inorganic form of arsenic.