Statistical Analysis of Influence of Soil Source on Leaching of Arsenic and Copper from CCA-C Treated Wood

Authors

  • Patricia Lebow
  • Richard Ziobro
  • Linda Sites
  • Tor Schultz
  • David Pettry
  • Darrel Nicholas
  • Stan Lebow
  • Pascal Kamdem
  • Roger Fox
  • Douglas Crawford

Keywords:

CCA-C, depletion, leaching, soil, wood preservative

Abstract

Leaching of wood preservatives affects the long-term efficacy and environmental impact of treated wood. Soil properties and wood characteristics can affect leaching of wood preservatives, but these effects are not well understood. This paper reports a statistical analysis of the effects of soil and wood properties on leaching of arsenic (As) and copper (Cu) from southern yellow pine sapwood treated with chromated copper arsenate (CCA-C). Specimens were leached by an accelerated laboratory method for 12 weeks in soil obtained from different locations or in water. Loss of Cu and As was measured using X-ray fluorescence and correlated with various physical and chemical soil properties. Leaching was greater from specimens with higher initial As and Cu retentions. Average Cu loss was approximately equal to or greater than As loss for specimens exposed to soil; for specimens leached in water, As loss was about twice that of Cu loss. Generally, more Cu leaching occurred from specimens in soil contact compared to specimens in water, suggesting that ground-contact leaching studies of the new copper-rich systems should employ soil-based methods for realistic depletion measurements. The amount of As and Cu leached was influenced by soil properties. Depletion of Cu and As from CCA-treated wood appears to be differentially related to various soil properties as well as to initial As and Cu retention in the wood. This research will help develop a standard laboratory method for soil-contact leaching of metals from CCA and other copper-based preservative systems.

References

Archer, K., and L. Jin. 1994. An investigation into the influence of soil cation exchange capacity on preservative component deletion. IRG doc. 94-20050.nAWPA. 2002. Standard method for analysis of treated wood and treating solutions by X-ray spectroscopy, Standard A9-01. Am. Wood-Preserv. Assoc., Granbury, TX.nCooper, P. A. 1991. Leaching of CCA from treated wood: pH effects. Forest Prod. J.41(1):30-32.nCooper, P. A. 2003. Leaching of CCA-facts and contradictions. Pages 73-99 in Proc., 99th Annual Meeting of American Wood Preservers' Association, Boston, MA.nCooper, P. A. and Y. T. Ung. 1992. Leaching of CCA-C from jack pine sapwood in compost. Forest Prod. J.42(9):57-59.nCrawford, D., R. Fox, K. Pascal, S. Lebow, D. Nicholas, D. Pettry, T. Schultz, L. Sites, and R. Ziobro. 2002. Laboratory studies of CCA-C leaching: Influence of wood and soil properties on extent of arsenic and copper depletion. IRG doc. 02-50186.nEdlund, M.-L., and T. Nilsson. 1999. Performance of copper and non-copper based wood preservatives in terrestrial microcosms. Holzforschung53:369-375.nFriendly, M. 2002. Corrgrams: Exploratory displays for correlation matrices. Am. Stat.56:316-324.nInsightful Corporation. 2001. S-PLUS 6 for Windows guide to statistics. Vol. 1. Insightful Corporation, Seattle, WA. 712 pp.nLebow, S. T. 1996. Leaching of wood preservative components and their mobility in the environment. Gen. Tech. Rep. FPL-GTR-93, USDA Forest Service, Forest Products Lab., Madison, WI.nLebow, S. T., P.A. Cooper, and P. K. Lebow. 2004. Variability in evaluating environmental impacts of treated wood. In Proc., Environmental Impacts of Preservative-Treated Wood, Orlando, FL.nLittell, R. C., G. A. Milliken, W.W. Stroup, and R. D. Wolfinger. 1996. SAS® system for mixed models. SAS Institute, Inc., NC, 633 pp.nMicklewright, J. T. 1999. Wood preservation statistics 1997. Am. Wood Preserv. Assoc., Granbury, TX.nMilliken, G. A., and D. E. Johnson. 2002. Analysis of messy data, Vol. III. Analysis of covariance. Chapman & Hall/CRC Press LLC, Boca Raton, FL, 605 pp.nMontgomery, D. C. 1997. Design and analysis of experiments. 4th ed. John Wiley & Sons, New York, NY. 704 pp.nMorris, P. I., J. K. Ingram, and D. L. Gent. 1993. Elimination of alternative explanations for the effect of iron on treated wood. IRGWP No. 30006.nNicholas, D. D. 1988. The influence of formulations on wood preservative performance. InProc., Am. Wood Preserv. Assoc.84:178-184.nPinheiro, J. C., and D. M. Bates. 2000. Mixed-effects models in S and S-PLUS. Springer-Verlag, New York, NY. 528 pp.nRuddick, J. N. R., and P. I. Morris. 1991. Movement of iron into field test stakes. Wood Protection1(1):23-29.nSAS Institute, Inc. 1999. SAS/STAT® user's guide, Version 8. SAS Institute Inc. Cary, NC, 3,884 pp.]nSchultz, T. P., D. D. Nicholas, and D. Pettry. 2002. Depletion of CCA-C from ground-contact wood: Results from two field sites with significantly different soils. Holzforschung56:125-129.nSchultz, T. P., D. D. Nicholas, and S. Lebow. 2003. Migration of iron and manganese into CCA-treated wood in soil contact and the resulting error in leaching results when using energy dispersive X-ray fluorescence spectrometers. Forest Prod. J.53(9):77-80.nSchultz, T. P., D. D. Nicholas, T. J. Dalton, and D. Keefe. 2004. Biocide retention variation of southern yellow pine products treated with water-borne preservatives in commercial, pilot plant or laboratory cylinders. Forest Prod. J.54(3): 85-90.nSenn, S. 1997. Statistical issues in drug development. John Wiley & Sons Ltd., Chichester, West Sussex, UK.nWang, J.-H., D. D. Nicholas, L. S. Sites, and D. E. Pettry. 1998. Effect of soil chemistry and physical properties on wood preservative leaching. IRG Doc.IRG/WP/98-50111.nWarren, J. E., and K. R. Solomon. 1990. Acidity as a factor in leaching of copper, chromium, and arsenic from CCAtreated dimension lumber. Environ. Toxicol. Chem.9:1331-1337.nXu, R. 2003. Measuring explained variation in linear mixed effects models. Statistics in Medicine 22:3527-3541.n

Downloads

Published

2007-06-05

Issue

Section

Research Contributions