Chromium, Copper, and Arsenic Concentrations in Soil Underneath CCA-Treated Wood Structures

Remediating Subsurface Arsenic Contamination with Monitored Natural Attenuation

“…For example, arsenic associated with sulfide minerals in mine tailings is released under oxidizing conditions, whereas arsenic associated with coal ash is released under reducing conditions. Inorganic arsenic can leach from wood treated with chromated copper arsenate (23), and methylated arsenical acids are often found at sites contaminated by the manufacture and/or use of arsenical biocides (24; Table S3). …”

Use of handheld X-ray fluorescence spectrometry units for identification of arsenic in treated wood

“…Although this preservative was phased out effective December 31, 2003 for most residential and consumer uses (US EPA, 2002), an abundance of treated wood containing arsenic can be found in outdoor structures and, as these structures age, they will ultimately enter wood recycling facilities and land-fills (Solo-Gabriele and Townsend, 1999). Treated wood containing arsenic is of environmental concern because some chemical may migrate from treated wood into the surrounding soil (Stilwell and Gorny, 1997;Townsend et al, 2003b) and groundwater (Khan et al, 2004;Townsend et al, 2003aTownsend et al, , 2004. Arsenic may also be dislodged from the treated wood surface upon contact with skin (Hemond and Solo-Gabriele, 2004;Shibata, 2006;Stilwell et al, 2003;US CPSC, 2003;US EPA, 2005).…”

Study Design Considerations in Evaluating Environmental Impacts

“…An observational study of the concentrations of arsenic, copper and chromium in soil under residential decks found that levels appeared to be lower under a deck that had been painted, although the design of that study did not allow a controlled comparison. 40 A laboratory study has also indicated that latex paint, oil-based paint and semitransparent penetrating stains are all effective in decreasing leaching from horizontal surfaces. 38 Again, although construction and maintenance activities generally cannot be controlled in an in-service leaching eval uation, they should be considered in the interpretation of leaching results.…”

“…This problem has generally been addressed by removing environmental samples at varying distances from the treated structure and considering those at an extended distance from the structure as representing the background concentration. [39][40][41] Although generally a valid approach, there is the concern that human activities probably are or have been greater in close proximity to the treated structure, and thus the risk of other sources of contamination is greater in that area than in other nearby but less-used areas.…”

“…[52][53][54] Environmental sampling typically yields many samples with relatively low levels of preservative components and a few samples with much higher level. 35,39,40 Because of this skewness, traditional normality-based statistical methods directly applied to samples from an underlying skewed distribution may be overly sensitive to the "out lying" observations and lack power in comparing parts of the distribution where there is less information. Lognormal distributions are commonly assumed in environmental sampling: Ott discusses in detail the physical and stochastic reasons why lognormal populations naturally arise in environmental settings.…”