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

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

U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available. In addition to updating the 2005 study, this report attempts to address a number of its shortcoming

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead