Expert Scientific Judgment and Cancer Risk Assessment: A Pilot Study of Pharmacokinetic Data

When high-dose tumor data are extrapolated to low doses, it is typically assumed that the dose of a carcinogen delivered to target cells is proportional to the dose administered to test animals, even at exposure levels below the experimental range. Since pharmacokinetic data are becoming available that in some cases question the validity of this assumption, risk assessors must decide whether to maintain the standard assumption. A pilot study of formaldehyde is reported that was undertaken to demonstrate how expert scientific judgment can help guide a controversial risk assessment where pharmacokinetic data are considered inconclusive. Eight experts on pharmacokinetic data were selected by a formal procedure, and each was interviewed personally using a structured interview protocol. The results suggest that expert scientific opinion is polarized in this case, a situation that risk assessors can respond to with a range of risk characterizations considered biologically plausible by the experts. Convergence of expert opinion is likely in this case of several specific research strategies ar executed in a competent fashion. Elicitation of expert scientific judgment is a promising vehicle for evaluating the quality of pharmacokinetic data, expressing uncertainty in risk assessment, and fashioning a research agenda that offers possible forging of scientific consensus.     

Risk Prevention and Policy-Making in Automatic Systems

Accidents with automatic production systems are reported to be on the order of one in a hundred or thousand robot-years, while fatal accidents are found to occur one or two orders of magnitude less frequently. Traditions in occupational safety tend to seek for safety targets in terms of zero severe accidents for automatic systems. Decision-making requires a risk assessment balancing potential risk reduction measures and costs within the cultural environment of a production company. This paper presents a simplified procedure which acts as a decision tool. The procedure is based on a risk concept approaching prevention both in a deterministic and in a probabilistic manner. Eight accident scenarios are shown to represent the potential accident processes involving robot interactions with people. Seven prevention policies are shown to cover the accident scenarios in principle. An additional probabilistic approach may indicate which extra safety measures can be taken against what risk reduction and additional costs. The risk evaluation process aims at achieving a quantitative acceptable risk level. For that purpose, three risk evaluation methods are discussed with respect to reaching broad consensus on the safety targets.     

Risk Assessment for Aflatoxin: An Evaluation Based on the Multistage Model

Lifetime cancer potency of alfatoxin was assessed based on the Yeh et al. study from China in which both aflatoxin exposure and hepatitis B prevalence were measured. This study provides the best available information for estimating the carcinogenic risk posed by aflatoxin to the U.S. population. Cancer potency of aflatoxin was estimated using a biologically motivated risk assessment model. The best estimate of aflatoxin potency was 9 (mg/kg/day)⁻¹ for individuals negative for hepatitis B and 230 (mg/kg/day)⁻¹ for individuals positive for hepatitis B.     

Attitudes Toward Managing Hazardous Waste: What Should Be Cleaned Up and Who Should Pay for It?

Hazardous waste policy in the United States uses a liability-based approach, including strict, retroactive, and joint and several liability. To assess attitudes toward these basic principles of liability, and toward priorities for clean-up of wastes, a questionnaire was mailed to legislators, judges, executives of oil and chemical companies, environmentalists, and economists. The questionnaire consisted of abstract, simplified cases, which contrasted basic principles rather than dealing with real-world scenarios. Subjects were asked how they would allocate clean-up costs between companies and government as a function of such factors as adherence to standards, adoption of best available technology (BAT), and influence of penalties on future behavior. Most subjects felt that, if the company followed government standards or used the best available technology (BAT), it should pay for only a portion of the clean-up cost, with the government paying the rest. In general, responses did not support the principles underlying current law–strict, retroactive, and joint-and-several liability. Most subjects were more interested in polluters paying for damages than in deterrence or future benefit–even to the extent that they would have "harmless" waste sites cleaned up. A bias was found toward complete clean-up of some sites, or "zero risk." Different groups of subjects gave similar answers, although more committed environmentalists were more willing to make companies pay and to clean up waste regardless of the cost.     

Learning from the Piper Alpha Accident: A Postmortem Analysis of Technical and Organizational Factors

The accident that occurred on board the offshore platform Piper Alpha in July 1988 killed 167 people and cost billions of dollars in property damage. It was caused by a massive fire, which was not the result of an unpredictable "act of God" but of an accumulation of errors and questionable decisions. Most of them were rooted in the organization, its structure, procedures, and culture. This paper analyzes the accident scenario using the risk analysis framework, determines which human decision and actions influenced the occurrence of the basic events, and then identifies the organizational roots of these decisions and actions. These organizational factors are generalizable to other industries and engineering systems. They include flaws in the design guidelines and design practices (e.g., tight physical couplings or insufficient redundancies), misguided priorities in the management of the tradeoff between productivity and safety, mistakes in the management of the personnel on board, and errors of judgment in the process by which financial pressures are applied on the production sector (i.e., the oil companies' definition of profit centers) resulting in deficiencies in inspection and maintenance operations. This analytical approach allows identification of risk management measures that go beyond the purely technical (e.g., add redundancies to a safety system) and also include improvements of management practices.     

基因技术的社会风险

基因技术给人类的生存与发展提供了许多希望。但是,基因技术对人类健康和生态环境具有潜在危害,对社会稳定和社会安全产生威胁,对人类价值观产生冲击,从而在社会各个层面产生意想不到的后果。因此,探讨基因技术将给人类带来的社会风险,提前采取预防措施,做到“未雨绸缪,防患于未然”,有助于促进基因技术的良性发展。     

高度现代性条件下知识缺失与风险叠加

知识缺失有制度化的因素,但是也有规律性的特征.在人类知识高速增长的同时,我们还严重缺乏知识.知识的缺失导致行动无据,过度防御行为使得本原风险出现叠加效应.知识史上知识饱和与知识缺失相伴而生,一方面我们拥有不断增长的社会知识,这些知识在提高人类战胜各类灾害减少风险和获取较高安全保障水平的同时也增强了我们制造风险的能力;另一方面我们应对突发性社会风险的知识又严重短缺,知识缺失使我们更加脆弱和易损,从而使我们的社会进入风险时代.     

Pricing and momentum of syndicated credit in Europe

We investigate the determinants of syndicated loan prices for European borrowers, spanning the entire period of credit expansion and crisis. We construct a large data base consisting of 2102 rated syndicated loan deals from 1990 to 2008 in twenty three countries and ten economic sectors. We investigate the effects on the spread paid over the risk free rate of three major groups of factors: loan characteristics, borrower characteristics and characteristics of country of the borrower, using both qualitative and quantitative variables in a hedonic regression. The results show that all three groups are significant joint determinants of prices of syndicated credit. Our results confirm the existing literature but also provide for first time results stemming form the risk characteristics of the borrower and the country of the borrower. It is shown that distance-to-default as well as aggregate risk associated with country of the borrower are of great concern to the lenders and hence significantly affect the pricing of syndicated loans. Furthermore, we report that financial institutions and public utilities are able to negotiate for cheaper loans, but this result is reversed when financing is for acquisition purposes. Overall, risk, liquidity, solvency and sustainable performance by both the borrower and its domicile country are key determinants of syndicated loan prices.     

Beyond a Simple Case of Black and White: Searching for the White Male Effect in the African-American Community

Prior research focusing on risk perceptions has led to the observation that well‐educated and politically conservative white males tend to systematically perceive lower levels of risk from a wide range of hazards when compared to other members of society (e.g., white women, nonwhite women and men). While this “white male effect (WME)” is quite striking given that many policymakers fall into this group, a byproduct of this finding is that it deflects attention from the heterogeneity, in terms of people's concerns about risks, that exists in African‐American and other minority communities. The research reported here set out to explore this heterogeneity by asking a simple question: Can a phenomenon similar to the WME be found in the African‐American community? It can, and its implications for research and practice in risk management are discussed.     

英语阅读抑制视域的歧义容忍度研究

本文基于英语阅读抑制与歧义容忍度的心理学同构关系,从英语阅读抑制视域角度审视歧义容忍度的倾向反应,指导学习者正确面对英语阅读中的陌生语言现象,帮助广大英语教师利用抑制效率调控学生的歧义容忍度,达到降低阅读焦虑、辅助元认知训练以及有效设置歧义场景的教学目的,促进学生英语阅读能力的提升.