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Hearn J.D.,Air Force Research Lab | Weber R.,U.S. Air force | Nichols R.,Universal Technology Corporation | Henley M.V.,Air Force Research Lab | Fox S.,Chemical Security Analysis Center
Journal of Hazardous Materials | Year: 2013

Synthetic soil blends were exposed to dense chlorine (Cl2) plumes released at Dugway Proving Ground, UT, during Spring 2010 with the purpose of determining the magnitude of Cl2 deposition onto soil and assessing its potential for attenuating a high-concentration plume. Samples were exposed at varying distances from the release point to include exposure to the pooling liquid (2-3m) and dense vapor (10-17m). Following exposure, soil samples were cored, fractionated vertically and analyzed for chloride (Cl-) to quantify the integrated amount of Cl2 deposited. Cl- was detected as deep as 4cm in samples exposed to dense Cl2 vapor and in the deepest fractions (13cm) of samples exposed to liquid Cl2. Chloride concentration, [Cl-], in the soil samples positively correlated with soil mass fractions of organic matter and water, and while their individual contributions to Cl2 deposition could not be quantitatively determined, the data suggest that organic matter was the primary contributor. [Cl-] results from the top vertical fractions (1.3cm nearest the surface) were used in an analysis to determine the magnitude of deposition as a loss term under low-wind (≤1.6m/s) conditions. The analysis revealed up to 50% of a 1814-kg release could be deposited within 20m from the release point for soil with high organic matter (43%) and/or water content (29%). © 2013. Source


Sommerville D.R.,U.S. Army | Bray J.J.,OptiMetrics, Inc. | Reutter-Christy S.A.,U.S. Army | Jablonski R.E.,Chemical Security Analysis Center | Shelly E.E.,U.S. Army
Military Operations Research | Year: 2010

New human estimates for chlorine inhalation lethality as a function of exposure duration were derived via a review and statistical analysis of existing mammalian lethality data. Such estimates are needed to support risk assessments and casualty predictions involving airborne releases of chlorine. At present, casualty predictions for such releases are at odds with what has been observed historically; the predicted downwind hazard area has often been much larger than what was actually observed. Either the present estimates for median lethal dosages (LCT50) are too low, the currently popular atmospheric transport and dispersion (ATD) models cannot adequately model chlorine releases, or both. LCT50 and quantal response data were analyzed for eight species (mouse, rat, guinea pig, rabbit, cat, dog, goat and sheep), for exposure durations from 8 to 235 minutes. The base 10 probit slope (concentration) was estimated via the weighted average of experimentally measured slopes in mammalian lethality studies. Resulting human lethality (military) estimates as a function of exposure duration were expressed via the toxic load model. General population estimates were derived from the military estimates using the mathematical method of Crosier (2007). Previous human estimates were reviewed and compared to the new general population estimate. The impact of the new estimate was evaluated through a series of transport and dispersion modeling runs for the catastrophic accidental release of 50 tons of chlorine from a tanker car. The sensitivity of downwind hazard distances was also investigated as a function of median lethal toxic load (TL), toxic load exponent and probit slope values. Source


Famini G.,Chemical Security Analysis Center | Emmett G.,Battelle
Global Congress on Process Safety 2012 - Topical Conference at the 2012 AIChE Spring Meeting and 8th Global Congress on Process Safety | Year: 2012

Increasing the safety and security within the chemical supply chain (CSC) has been a concern of the United States (U.S.) Government for several years. The Environmental Protection Agency and the U.S. Department of Homeland Security (DHS) have active efforts to reduce societal risk of a toxic industrial chemical release. Inherently safer technology (IST) has been proffered as a potential solution for addressing a number of these safety and security shortfalls. Indeed, IST concepts have been used successfully and when coupled with other safer design strategies, they offer valid solutions in improving both safety and security and reducing societal risk. Before any solution including IST can be employed, the underlying science must be fully understood and characterized. This presentation will focus on the efforts by the DHS Chemical Security Analysis Center to evaluate the underlying scientific groundwork so that IST and safer design strategies may be applied in a broader context to improve the security of the CSC. Source


Famini G.,Chemical Security Analysis Center | Emmett G.,Chemical Security Analysis Center
AIChE Annual Meeting, Conference Proceedings | Year: 2012

Increasing the safety and security within the chemical supply chain (CSC) has been a concern of the United States (U.S.) Government for several years. The Environmental Protection Agency and the U.S. Department of Homeland Security (DHS) have active efforts to reduce societal risk of a toxic industrial chemical release. Inherently safer technology (IST) has been proffered as a potential solution for addressing a number of these safety and security shortfalls. Indeed, IST concepts have been used successfully and when coupled with other safer design strategies, they offer valid solutions in improving both safety and security and reducing societal risk. Before any solution including IST can be employed, the underlying science must be fully understood and characterized. This presentation will focus on the efforts by the DHS Chemical Security Analysis Center to evaluate the underlying scientific groundwork so that IST and safer design strategies may be applied in a broader context to improve the security of the CSC. Source


Good K.,Battelle | Winkel D.,Battelle | VonNiederhausern M.,Battelle | Hawkins B.,Battelle | And 3 more authors.
Journal of Medical Toxicology | Year: 2013

The Chemical Terrorism Risk Assessment (CTRA) and Chemical Infrastructure Risk Assessment (CIRA) are programs that estimate the risk of chemical terrorism attacks to help inform and improve the US defense posture against such events. One aspect of these programs is the development and advancement of a Medical Mitigation Model-a mathematical model that simulates the medical response to a chemical terrorism attack and estimates the resulting number of saved or benefited victims. At the foundation of the CTRA/CIRA Medical Mitigation Model is the concept of stock-and-flow modeling; "stocks" are states that individuals progress through during the event, while "flows" permit and govern movement from one stock to another. Using this approach, the model is able to simulate and track individual victims as they progress from exposure to an end state. Some of the considerations in the model include chemical used, type of attack, route and severity of exposure, response-related delays, detailed treatment regimens with efficacy defined as a function of time, medical system capacity, the influx of worried well individuals, and medical countermeasure availability. As will be demonstrated, the output of the CTRA/CIRA Medical Mitigation Model makes it possible to assess the effectiveness of the existing public health response system and develop and examine potential improvement strategies. Such a modeling and analysis capability can be used to inform first-responder actions/training, guide policy decisions, justify resource allocation, and direct knowledge-gap studies. © 2012 American College of Medical Toxicology. Source

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