Using Epidemiological Studies to Check the Consistency of the Cancer Risks Predicted by High-Dose Animal Experiments: A Methodological Review

Epidemiological studies have been cited in the literature as evidence both for and against the human cancer risks predicted by high-exposure rodent studies. However, there has been little overall consistency in the ways that these animal-to-human comparisons have been made. This review examines some examples of these types of comparisons and describes the methods and techniques used by different investigators. Eleven "key decision areas" that need to be addressed are identified and recommendations for consistent, logical, and statistically appropriate approaches that might be taken to standardize the process are provided. In general, it is suggested that investigators provide the most useful information when they use logical, transparent, and statistically valid comparisons to pursue limited and focused objectives, such as directly testing the validity of an existing regulatory guidance value. Other recommendations include selecting biologically plausible extrapolative models that fit the data and drawing conclusions that are consistent with the study results and objectives.     

The Rise in Union Wage Premiums in South Africa

The earnings premium received by African, urban, male union members in South Africa, as compared to other regular, urban male employees, is explored using two national sample surveys conducted in 1985 and 1993. The historical setting of this change is of particular interest, in the light of the transformation from the apartheid regime. Union membership grew very rapidly during this interval, as earlier prohibitions on African unions were lifted. Subsequently, the high rates of unemployment and segmentation of the labor force have been issues of central concern to the new government, elected in 1994. In this context, the paper extends prior methodology, by systematically comparing possible approaches to estimation, in addition to contributing fresh empirical results. Four approaches to estimation are adopted, allowing for: a single earnings regime with union dummy variable; the possibility of different earnings regimes among union members as compared to non‐members; endogenous switching between such regimes; sample selection arising from lack of employment and from division between regular and informal work. A series of tests on nested specifications indicate the importance of recognizing endogenous switching between differing pay structures in the covered and uncovered sectors. However (as with previous research on the South African labor market), no sample selection is detected with respect to employment status. The results suggest that collective bargaining resulted in wage compression among the expanding union membership while significantly widening the gap between members and non‐members. The latter widening gap cannot be attributed to the changing composition of union membership as reflected in observed characteristics of employees.     

COMPARING THE ENVIRONMENTAL AND QUALITY INITIATIVES OF BALDRIGE AWARD WINNERS

Can best‐practice quality firms leverage their quality programs for environmental management? This paper explores this question by comparing the implementation of successful and unsuccessful quality and environmental initiatives in five manufacturing‐ and five service‐sector Malcolm Baldrige National Quality Award (mbnqa) winners. The results lead to a series of propositions to guide future research. While the literature suggests that quality and environmental programs are closely related, this study finds that drivers of successful environmental initiatives are not the same as those for successful quality initiatives.     

Leadership,Passion and Performance: A Study of Job Creation Projects during the Recession

In the aftermath of the economic recession that began in 2008, governmental bodies have been assisting private sector companies to create jobs. To increase financial performance under greater economic uncertainty and liquidity constraints, this study proposes that a leader's type of passion could explain why some project leaders who receive government funding succeed in creating jobs whereas others do not. Harmonious passion, a voluntary but not overpowering urge to engage in an activity, leads to higher job creation, especially under greater environmental complexity. Obsessive passion, an uncontrollable urge to engage in an activity, also leads to higher job creation, particularly under increasing environmental dynamism. Using survey data from 105 European Union projects and archival data on job creation from the EU funding agency, we find support for the proposed framework. The findings provide a basis for acknowledging the relevance of a leader's passion for environmental adaptation.     

Portfolio Analysis of Layered Security Measures

Layered defenses are necessary for protecting the public from terrorist attacks. Designing a system of such defensive measures requires consideration of the interaction of these countermeasures. In this article, we present an analysis of a layered security system within the lower Manhattan area. It shows how portfolios of security measures can be evaluated through portfolio decision analysis. Consideration is given to the total benefits and costs of the system. Portfolio diagrams are created that help communicate alternatives among stakeholders who have differing views on the tradeoffs between security and economic activity.     

Diesel Engine Exhaust and Lung Cancer Mortality: Time‐Related Factors in Exposure and Risk

To develop a quantitative exposure‐response relationship between concentrations and durations of inhaled diesel engine exhaust (DEE) and increases in lung cancer risks, we examined the role of temporal factors in modifying the estimated effects of exposure to DEE on lung cancer mortality and characterized risk by mine type in the Diesel Exhaust in Miners Study (DEMS) cohort, which followed 12,315 workers through December 1997. We analyzed the data using parametric functions based on concepts of multistage carcinogenesis to directly estimate the hazard functions associated with estimated exposure to a surrogate marker of DEE, respirable elemental carbon (REC). The REC‐associated risk of lung cancer mortality in DEMS is driven by increased risk in only one of four mine types (limestone), with statistically significant heterogeneity by mine type and no significant exposure‐response relationship after removal of the limestone mine workers. Temporal factors, such as duration of exposure, play an important role in determining the risk of lung cancer mortality following exposure to REC, and the relative risk declines after exposure to REC stops. There is evidence of effect modification of risk by attained age. The modifying impact of temporal factors and effect modification by age should be addressed in any quantitative risk assessment (QRA) of DEE. Until there is a better understanding of why the risk appears to be confined to a single mine type, data from DEMS cannot reliably be used for QRA.     

Understanding Gaps Between the Risk Perceptions of Wildland–Urban Interface (WUI) Residents and Wildfire Professionals

Research across a variety of risk domains finds that the risk perceptions of professionals and the public differ. Such risk perception gaps occur if professionals and the public understand individual risk factors differently or if they aggregate risk factors into overall risk differently. The nature of such divergences, whether based on objective inaccuracies or on differing perspectives, is important to understand. However, evidence of risk perception gaps typically pertains to general, overall risk levels; evidence of and details about mismatches between the specific level of risk faced by individuals and their perceptions of that risk is less available. We examine these issues with a paired data set of professional and resident assessments of parcel‐level wildfire risk for private property in a wildland–urban interface community located in western Colorado, United States. We find evidence of a gap between the parcel‐level risk assessments of a wildfire professional and numerous measures of residents’ risk assessments. Overall risk ratings diverge for the majority of properties, as do judgments about many specific property attributes and about the relative contribution of these attributes to a property's overall level of risk. However, overall risk gaps are not well explained by many factors commonly found to relate to risk perceptions. Understanding the nature of these risk perception gaps can facilitate improved communication by wildfire professionals about how risks can be mitigated on private lands. These results also speak to the general nature of individual‐level risk perception.