SAMPLING OF SOILS WITH METALLIC RESIDUES COLLECTED FROM MILITARY SMALL-ARMS RANGES

Small-arms, artillery, mortar, and pyrotechnic military training introduces solid metallic residues into the environment. Previous energetic residue research showed conventional judgmental soil sampling and associated sample preparation methodologies are inadequate to address the heterogeneous distribution and still yield representative and reproducible results for the area of interest. Metallic residue deposition at military small-arms ranges occurs in a heterogeneous distributional pattern, similar to solid particulate energetic residue deposition. One of the primary objectives of an environmental investigation is to estimate the mean contaminant concentration to evaluate human and ecological risk in an exposure unit (i.e., an area where the receptors are exposed to contamination). One assumption of the risk assessment is that the receptors spend an equal amount of time in every portion of the exposure unit. Evaluation of the appropriateness of conventional soil sampling for military small-arms ranges with solid metallic residues indicated the conventional approach of judgmental sampling was inadequate for providing representative and reproducible mean estimates for the exposure unit. Consequently, a series of experiments evaluated possible changes to the field sampling and laboratory sample preparation procedures to improve the representativeness and reproducibility of the sample results. The outcome of this study found that a collective series of changes involving soil sampling and sample preparation procedures provided superior estimates of the population (exposure unit) relative to conventional grab sampling. Overall, the dissertation results indicate a sampling approach referred to as the Incremental Sampling Methodology (ISM) provided an improved estimate of the population (exposure unit) relative to conventional grab sampling and has the potential to reduce sampling costs by 5 to 50 percent. Incorporation of the dissertation findings into suggested modifications for United States Environmental Protection Agency SW-846 Method 3050B for digestion of soils or sediments undergoing metals analysis is in progress; including the addition of an appendix outlining the procedures for collection of systematic random surface soil samples in the field using the incremental approach

Investigation of the reduction of NiAl{sub 2}O{sub 4}. 1: Neutron diffraction studies

In-situ metal-ceramic composites consisting of Ni particles embedded in alumina matrices were obtained by the partial reduction of NiAl{sub 2}O{sub 4}. The volume shrinkage that accompanies the reduction reaction generates residual stresses. Neutron diffraction studies were performed for the first time at various temperatures to study the evolution of phases in situ during reduction and to determine their stress state. It was determined that compressive stresses of several hundred MPa in magnitude can be generated inside the unreduced part of spinel. It was also found that the stress generation is strongly influenced by material and processing variables such as reduction temperature and the initial density of spinel. The diffraction results were then compared to finite element calculations and a reasonable agreement was obtained

Tungsten Speciation and Solubility in Munitions-Impacted Soils

Considerable questions persist regarding tungsten geochemistry in natural systems, including which forms of tungsten are found in soils and how adsorption regulates dissolved tungsten concentrations. In this study, we examine tungsten speciation and solubility in a series of soils at firing ranges in which tungsten rounds were used. The metallic, mineral, and adsorbed forms of tungsten were characterized using X-ray absorption spectroscopy and X-ray microprobe, and desorption isotherms for tungsten in these soils were used to characterize its solid–solution partitioning behavior. Data revealed the complete and rapid oxidation of tungsten metal to hexavalent tungsten­(VI) and the prevalence of adsorbed polymeric tungstates in the soils rather than discrete mineral phases. These polymeric complexes were only weakly retained in the soils, and porewaters in equilibrium with contaminated soils had 850 mg L^–1 tungsten, considerably in excess of predicted solubility. We attribute the high solubility and limited adsorption of tungsten to the formation of polyoxometalates such as W₁₂SiO₄₀^4–, an α-Keggin cluster, in soil solutions. Although more research is needed to confirm which of such polyoxometalates are present in soils, their formation may not only increase the solubility of tungsten but also facilitate its transport and influence its toxicity

Development of an integrated in-situ remediation technology. Topical report for task No. 11 entitled: Evaluation of TCE contamination before and after the field experiment, September 26, 1994--May 25, 1996

Contamination in low permeability soils poses a significant technical challenge to in-situ remediation efforts. Poor accessibility to the contaminants and difficulty in delivery of treatment reagents have rendered existing in-situ treatments such as bioremediation, vapor extraction, pump and treat rather ineffective when applied to low permeability soils present at many contaminated sites. The technology is an integrated in-situ treatment in which established geotechnical methods are used to install degradation zones directly in the contaminated soil and electro-osmosis is utilized to move the contaminants back and forth through those zones until the treatment is completed. The present Topical Report for Task No. 11 summarizes the results of TCE analysis in soil and carbon before and after conducting the field experiment. In addition, a discussion of the TCE material balance demonstrates that the Lasagna{trademark} process is effective in moving TCE from the contaminated soil into carbon treatment zones in the field experiment at DOE`s Gaseous Diffusion Plant in Paducah, Kentucky

Effect of physical exercise on workplace social capital: cluster randomized controlled trial

Abstract in Undetermined While workplace health promotion with group-based physical exercise can improve workers' physical health, less is known about potential carry-over effects to psychosocial factors. This study investigates the effect of physical exercise on social capital at work

Priorities of Municipal Policy Makers in Relation to Physical Activity and the Built Environment: A Latent Class Analysis

OBJECTIVE: To examine policy makers\u27 public policy priorities related to physical activity and the built environment, identify classes of policy makers based on priorities using latent class analysis, and assess factors associated with class membership. DESIGN: Cross-sectional survey data from municipal officials in 94 cities and towns across 6 US states were analyzed. PARTICIPANTS: Participants (N = 423) were elected or appointed municipal officials spanning public health, planning, transportation/public works, community and economic development, parks and recreation, and city management. MAIN OUTCOME MEASURES: Participants rated the importance of 11 policy areas (public health, physical activity, obesity, economic development, livability, climate change, air quality, natural resource conservation, traffic congestion, traffic safety, and needs of vulnerable populations) in their daily job responsibilities. Latent class analysis was used to determine response patterns and identify distinct classes based on officials\u27 priorities. Logistic regression models assessed participant characteristics associated with class membership. RESULTS: Four classes of officials based on policy priorities emerged: (1) economic development and livability; (2) economic development and traffic concerns; (3) public health; and (4) general (all policy areas rated as highly important). Compared with class 4, officials in classes 1 and 3 were more likely to have a graduate degree, officials in class 2 were less likely to be in a public health job/department, and officials in class 3 were more likely to be in a public health job/department. CONCLUSIONS: Findings can guide public health professionals in framing discussions with policy makers to maximize physical activity potential of public policy initiatives, particularly economic development

Multianalyzer Spectroscopic Data Fusion for Soil Characterization

The ability to rapidly conduct in-situ chemical analysis of multiple samples of soil and other geological materials in the field offers many advantages over a traditional approach that involves collecting samples for subsequent examination in the laboratory. This study explores the application of complementary spectroscopic analyzers and a data fusion methodology for the classification/discrimination of >100 soil samples from sites across the United States. Commercially available, handheld analyzers for X-ray fluorescence spectroscopy (XRFS), Raman spectroscopy (RS), and laser-induced breakdown spectroscopy (LIBS) were used to collect data both in the laboratory and in the field. Following a common data pre-processing protocol, principal component analysis (PCA) and partial least squares discriminant analysis (PLSDA) were used to build classification models. The features generated by PLSDA were then used in a hierarchical classification approach to assess the relative advantage of information fusion, which increased classification accuracy over any of the individual sensors from 80-91% to 94% and 64-93% to 98% for the two largest sample suites. The results show that additional testing with data sets for which classification with individual analyzers is modest might provide greater insight into the limits of data fusion for improving classification accuracy