Adversarial safety analysis: borrowing the methods of security vulnerability assessments

INTRODUCTION: Safety and security share numerous attributes. The author, who heads the (Security) Vulnerability Assessment Team at Los Alamos National Laboratory, therefore argues that techniques used to optimize security might be useful for optimizing safety. OPTIMIZING SECURITY: There are three main ways to attempt to improve security-security surveys, risk assessment (or "design basis threat"), and vulnerability assessments. The latter is usually the most effective. SAFETY ANALOGS: Vulnerability assessment techniques used to improve security can be applied to safety analysis--even though safety is not ordinarily viewed as having malicious adversaries (other than hazards involving deliberate sabotage). Thinking like a malicious adversary can nevertheless have benefits in identifying safety vulnerabilities. SUGGESTIONS: The attributes of an effective safety vulnerability assessment are discussed, and recommendations are offered for how such an adversarial assessment might work. CONCLUSION: A safety vulnerability assessment can potentially provide new insights, a fresh and vivid perspective on safety hazards, and increased safety awareness.     

Health risk assessment of PCDD/F emissions from a hazardous and medical waste incinerator in Turkey

A multimedia risk assessment procedure was conducted to determine the fate and transport of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emissions from the Izmit Hazardous and Medical Waste Incinerator (IZAYDAS) in Turkey and their potential health risks. Congener concentrations in ambient air and their deposition rates were determined by an air dispersion model (ISCST3). Their transfer to some plant groups and animal tissues was predicted by food chain modeling. Exposure scenarios were produced based on three receptor groups (urban, semiurban, and rural) and five subgroups determined according to ages. Daily intakes of PCDD/Fs via exposure pathways were determined based on three different emission scenarios for each group and subgroup. Estimated incremental PCDD/F doses caused by the incinerator emissions in central-tendency scenario were computed as between 2.31 x 10(-6) and 0.008 pg TEQ kg(-1) bodyweight (bw) day(-1) on average for all the receptors other than infants in all the settings, while the range was 3.01 x 10(-5)-0.081 pg TEQ kg(-1) bw day(-1) for infants. Sensitivity analysis showed that the consumption of vegetal products and their locally grown fractions are the most significant parameters in the exposure to PCDD/Fs in the area.     

The ecological effects of trichloroacetic acid in the environment

Trichloroacetic acid (TCAA) is a member of the family of compounds known as chloroacetic acids, which includes mono-, di- and trichloroacetic acid. The significant property these compounds share is that they are all phytotoxic. TCAA once was widely used as a potent herbicide. However, long after TCAA's use as a herbicide was discontinued, its presence is still detected in the environment in various compartments. Methods for quantifying TCAA in aqueous and solid samples are summarized. Concentrations in various environmental compartments are presented, with a discussion of the possible formation of TCAA through natural processes. Concentrations of TCAA found to be toxic to aquatic and terrestrial organisms in laboratory and field studies were compiled and used to estimate risk quotients for soil and surface waters. TCAA levels in most water bodies not directly affected by point sources appear to be well below toxicity levels for the most sensitive aquatic organisms. Given the phytotoxicity of TCAA, aquatic plants and phytoplankton would be the aquatic species to monitor for potential effects. Given the concentrations of TCAA measured in various soils, there appears to be a risk to terrestrial organisms. Soil uptake of TCAA by plants has been shown to be rapid. Also, combined uptake of TCAA from soil and directly from the atmosphere has been shown. Therefore, risk quotients derived from soil exposure may underestimate the risk TCAA poses to plants. Moreover, TCE and TCA have been shown to be taken up by plants and converted to TCAA, thus leading to an additional exposure route. Mono- and di-chloroacetic acids can co-occur with TCAA in the atmosphere and soil and are more phytotoxic than TCAA. The cumulative effects of TCAA and compounds with similar toxic effects found in air and soil must be considered in subsequent terrestrial ecosystem risk assessments.     

Modeling the Suitability of Potential Wetland Mitigation Sites with a Geographic Information System

Wetland mitigation is frequently required to compensate for unavoidable impacts to wetlands. Site conditions and landscape context are critical factors influencing the functions that created wetlands perform. We developed a spatial model and used a geographic information system (GIS) to identify suitable locations for wetland mitigation sites. The model used six variables to characterize site conditions: hydrology, soils, historic condition, vegetation cover, adjacent vegetation, and land use. For each variable, a set of suitability scores was developed that indicated the wetland establishment potential for different variable states. Composite suitability scores for individual points on the landscape were determined from the weighted geometric mean of suitability scores for each variable at each point. These composite scores were grouped into five classes and mapped as a wetland mitigation suitability surface with a GIS. Sites with high suitability scores were further evaluated using information on the feasibility of site modification and project cost. This modeling approach could be adapted by planners for use in identifying the suitability of locations as wetland mitigation sites at any site or region.     

改进BP算法在煤与瓦斯突出预测中的应用

为了正确预测煤与瓦斯突出的趋势与危险性 ,基于反向BP神经网络 ,笔者提出了一种改进的BP网络模型 :为了加快BP网络的收敛速度 ,增强其跳出局部极小点的能力 ,采用了自适应变步长法和改进模拟退火法 (SA法 )相结合的方法。实际应用表明 ,该模型收敛速度快 ,准确性高 ,具有较高的可靠性和实用性 ,是一种十分有效的煤与瓦斯突出危险性预测方法。     

Adolescent driver risk taking and driver education: evidence of a mobility bias in public policymaking

PROBLEM: Road traffic injury is the leading cause of death among adolescents in high-income countries. Researchers attribute this threat to driver risk taking, which driver education (DE) attempts to reduce. Many North American authorities grant DE graduates earlier access to unsupervised driving despite no evidence of this being a safety benefit. This theoretical article examines risk taking and DE in relation to an apparent mobility bias (MB) in policymaking. METHOD: The MB is defined, the history and sources of driver risk taking are examined, and the failure of DE to reduce collision risk is analyzed in relation to a potential MB in licensing policies. DISCUSSION: The author argues that DE's failure to reduce adolescent collision risk is associated with a MB that has produced insufficient research into DE programs and that influences public policymakers to grant earlier licensure to DE graduates. Recommendations are made regarding future research on DE and risk taking, coordinated improvements to DE and driver licensing, and a plan to reduce collision risk by encouraging parental supervision after adolescent licensure. IMPACT ON INDUSTRY: Research on adolescent driver risk taking would have direct applications in DE curricula development, driver's license evaluation criteria, graduated licensing (GDL) policies, as well as other aspects of human factor research into the crash-risk problem.     

Distractions and the risk of car crash injury: the effect of drivers' age

PROBLEM: Motor-vehicle accidents are one of the major causes of injury in most motorized countries. Driver distractions have been suggested as a contributor to traffic accidents. Moreover, age of the driver seems to have a role in the relationship between distractions and car crashes. But very few studies have investigated the effect of driver's age on this relationship. This exploratory study investigated the association between distractions, both inside and outside the vehicle, and the increased risk of car crash injury among drivers across different ages. METHOD: This study used a case series design to analyze data routinely collected by the NSW police in Australia. A special focus of this study was on how drivers' age affects the risk of car crash injury, which was determined by using a well-documented risk estimation methodology. RESULTS: The results obtained indicated that drivers of all ages, on the whole, are more susceptible to distractions inside the vehicle than distractions coming from outside. Age was shown to affect the relationship between in-vehicle distraction and the risk of car crash injury. A separate analysis was also conducted on hand-held phone usage while driving with results supplementing previous findings reported in the literature. IMPACT TO INDUSTRY: Safety strategies to countermeasure in-vehicle distractions have been suggested and discussed.     

县(市)级山地环境管理信息系统的研制--以庆元县为例

介绍了县(市)级山地环境管理信息系统(MEMIS)结构功能的设计、系统的实现和配置。以庆元县为例进行试验,结果表明：该系统具有山地环境稳定性评价和区划的功能,可为山地防灾区划提供新技术。     

An Investigation of Environmental Racism Claims: Testing Environmental Management Approaches with a Geographic Information System

The purpose of this research was to explore the concept of an environmental racism claim through the use of several environmental management tools. The EPAs Toxics Release Inventory, Cumulative Exposure Project, and the Los Angeles County Department of Health Services' Hot Zone Census Tract Assessment were combined with racial and socioeconomic data to test claims that minorities in South Central Los Angeles are disproportionately exposed to environmental lead. Multivariate analysis indicated that race is strongly associated with the number of cases of elevated blood lead levels in South Central, irrespective of poverty status. Proximity to point sources, a common focal point for studies of environmental racism, was not a contributing factor to health outcomes. Proximity to transportation corridors was consistently the strongest indicator of environmental lead exposure, while median home values were significantly and positively related to elevated blood lead levels. Implications for environmental justice advocates and social and environmental scientists are discussed.