Sampling Strategies for Toxic Air Contaminants

Annual concentrations of toxic air contaminants are of primary concern from the perspective of chronic human exposure assessment and risk analysis. Despite recent advances in air quality monitoring technology, resource and technical constraints often impose limitations on the availability of a sufficient number of ambient concentration measurements for performing environmental risk analysis. Therefore, sample size limitations, representativeness of data, and uncertainties in the estimated annual mean concentration must be examined before performing quantitative risk analysis. In this paper, we discuss several factors that need to be considered in designing field-sampling programs for toxic air contaminants and in verifying compliance with environmental regulations. Specifically, we examine the behavior of SO2, TSP, and CO data as surrogates for toxic air contaminants and as examples of point source, area source, and line source-dominated pollutants, respectively, from the standpoint of sampling design. We demonstrate the use of bootstrap resampling method and normal theory in estimating the annual mean concentration and its 95% confidence bounds from limited sampling data, and illustrate the application of operating characteristic (OC) curves to determine optimum sample size and other sampling strategies. We also outline a statistical procedure, based on a one-sided t-test, that utilizes the sampled concentration data for evaluating whether a sampling site is compliance with relevant ambient guideline concentrations for toxic air contaminants.     

Uncertainty Analysis Based on Probability Bounds (P-Box) Approach in Probabilistic Safety Assessment

A wide range of uncertainties will be introduced inevitably during the process of performing a safety assessment of engineering systems. The impact of all these uncertainties must be addressed if the analysis is to serve as a tool in the decision-making process. Uncertainties present in the components (input parameters of model or basic events) of model output are propagated to quantify its impact in the final results. There are several methods available in the literature, namely, method of moments, discrete probability analysis, Monte Carlo simulation, fuzzy arithmetic, and Dempster-Shafer theory. All the methods are different in terms of characterizing at the component level and also in propagating to the system level. All these methods have different desirable and undesirable features, making them more or less useful in different situations. In the probabilistic framework, which is most widely used, probability distribution is used to characterize uncertainty. However, in situations in which one cannot specify (1) parameter values for input distributions, (2) precise probability distributions (shape), and (3) dependencies between input parameters, these methods have limitations and are found to be not effective. In order to address some of these limitations, the article presents uncertainty analysis in the context of level-1 probabilistic safety assessment (PSA) based on a probability bounds (PB) approach. PB analysis combines probability theory and interval arithmetic to produce probability boxes (p-boxes), structures that allow the comprehensive propagation through calculation in a rigorous way. A practical case study is also carried out with the developed code based on the PB approach and compared with the two-phase Monte Carlo simulation results.     

Work, employment, and mental illness: expanding the domain of Canadian social work

Despite established evidence that work and employment are an important component of recovery for people who experience mental illness, social work education in Canada seldom offers graduate training or courses on the significance of work in peoples' lives or on the practices involved in helping to gain and retain employment for these individuals. In this article the authors argue that the high levels of unemployment among people who experience mental illness, and the rising incidence of mental health and addictions issues in workplaces, offer the opportunity, as well as the mandate, for social work educators to provide professional education in the area of employment support and assistance.     

Social Policy Practice

This paper identifies and discusses issues for a school of social work in the context of collective bargaining. Attention is given to the implications of collective bargaining on a professional social work program. The paper is based on a theoretical framework and an experience of approximately three years in the advent and development of collective bargaining in a large midwestern public university. Major substantive areas discussed have to do with intragroup and intergroup relations among students, community professionals, faculty and administration; the definition of “work” and “work load”; and the reward system for promotion, tenure, and recognition of merit. Major implications relate to the concerns of professionalism, the balancing of. democratic participation and responsible management, and the codification in contract of social work's historical role in participatory decision making.     

Current and Future Particulate‐Matter‐Related Mortality Risks in the United States from Aviation Emissions During Landing and Takeoff

Demand for air travel is projected to increase in the upcoming years, with a corresponding influence on emissions, air quality, and public health. The trajectory of health impacts would be influenced by not just emissions growth, but also changes in nonaviation ambient concentrations that influence secondary fine particulate matter (PM_2.5) formation, population growth and aging, and potential shifts in PM_2.5 concentration‐response functions (CRFs). However, studies to date have not systematically evaluated the individual and joint contributions of these factors to health risk trajectories. In this study, we simulated emissions during landing and takeoff from aircraft at 99 airports across the United States for 2005 and for a 2025 flight activity projection scenario. We applied the Community Multiscale Air Quality (CMAQ) model with the Speciated Modeled Attainment Test (SMAT) to determine the contributions of these emissions to ambient concentrations, including scenarios with 2025 aircraft emissions and 2005 nonaviation air quality. We combined CMAQ outputs with PM_2.5 mortality CRFs and population projections, and evaluated the influence of changing emissions, nonaviation concentrations, and population factors. Given these scenarios, aviation‐related health impacts would increase by a factor of 6.1 from 2005 to 2025, with a factor of 2.1 attributable to emissions, a factor of 1.3 attributable to population factors, and a factor of 2.3 attributable to changing nonaviation concentrations which enhance secondary PM_2.5 formation. Our study emphasizes that the public health burden of aviation emissions would be significantly influenced by the joint effects of flight activity increases, nonaviation concentration changes, and population growth and aging.     

An Integrated Approach for Modeling Sustainability Risks in Freight Transportation Systems

Integrating sustainability into freight transportation systems (FTSs) is a complex and challenging task due to the sheer number of inherent sustainability risks. Sustainability risks disrupt the economic, social and environmental objectives of freight operations and act as impediments in the development of sustainable freight transportation systems. The area of sustainability risk management is still unexplored and immature in the operational research domain. This study addresses these research gaps and contributes in a threefold manner. First, a total of 36 potential sustainability risks related to FTSs are identified and uniquely classified into seven categories using a rigourous approach. Second, the research proposes two prominent perspectives, namely, ontological and epistemological perspectives to understand risks and develops a novel framework for managing sustainability risks in FTSs. Third, a novel approach by integrating fuzzy evidential reasoning algorithm (FERA) with expected utility theory is developed to quantitatively model and profile sustainability risk for different risk preferences, namely, risk-averse, risk-neutral, and risk-taking scenarios. The proposed FERA is a flexible and robust approach, which transforms the experts’ inputs into belief structures and aggregates them using the evidence combination rule proposed in Dempster–Shafer theory to overcome the problem of imprecise results caused by average scoring in existing models. A sensitivity analysis is conducted to demonstrate the robustness of the proposed model. Unlike conventional perception, our study suggests that most of the high priority sustainability risks are behaviorally and socially induced rather than financially driven. The results provide significant managerial implications including a focus on skills development, and on social and behavioral dimensions while managing risks in FTSs.     

Behavior of agreement measures in the presence of zero cells and biased marginal distributions

Kappa and B assess agreement between two observers independently classifying N units into k categories. We study their behavior under zero cells in the contingency table and unbalanced asymmetric marginal distributions. Zero cells arise when a cross-classification is never endorsed by both observers; biased marginal distributions occur when some categories are preferred differently between the observers. Simulations studied the distributions of the unweighted and weighted statistics for k=4, under fixed proportions of diagonal agreement and different patterns off-diagonal, with various sample sizes, and under various zero cell count scenarios. Marginal distributions were first uniform and homogeneous, and then unbalanced asymmetric distributions. Results for unweighted kappa and B statistics were comparable to work of Muñoz and Bangdiwala, even with zero cells. A slight increased variation was observed as the sample size decreased. Weighted statistics did show greater variation as the number of zero cells increased, with weighted kappa increasing substantially more than weighted B. Under biased marginal distributions, weighted kappa with Cicchetti weights were higher than with squared weights. Both statistics for observer agreement behaved well under zero cells. The weighted B was less variable than the weighted kappa under similar circumstances and different weights. In general, B's performance and graphical interpretation make it preferable to kappa under the studied scenarios.     

Browse‐and‐Switch: Retail‐Online Competition under Value Uncertainty

Although online shopping is becoming popular, consumers who are unsure about whether to buy a product may find it advantageous to visit a brick‐and‐mortar retail store to first examine the product before purchasing it. But, after browsing at the store, consumers have the option of switching to an e‐tailer to purchase the item at a cheaper price rather than buying at the store. Recent business press refers to this browse‐and‐switch behavior as “showrooming,” and attributes to it the declining profits of brick‐and‐mortar retailers. To study the effect of the browse‐and‐switch option on retail and online pricing strategies and profits, we analyze a stylized economic model that incorporates uncertainty in consumers' valuation of the product, captures the heterogeneity among consumers in their inclination to purchase online, and permits product returns. We consider various equilibrium scenarios for different combinations of consumer shopping behaviors, characterize the parameter ranges for each scenario, and demonstrate that browse‐and‐switch behavior can indeed occur under equilibrium. Our analysis further shows that the option for consumers to browse‐and‐switch intensifies competition, reducing the profits for both firms.     

Does Good Governance Enhance Happiness: A Cross Nation Study

The purpose of this paper is to analyze the efficiency of the countries over the period of 10 years by applying data envelopment analysis (DEA). Based on rational and factual parameters such as freedom of press, freedom of religion, percentage of export in Gross Domestic Product (GDP), index of globalization, life expectancy at birth, gender ratio etc., this paper attempts to measure the efficiency of happiness. A combination of social and economic factors has been used to measure technical efficiency. The contribution of this paper is twofold. First, it measures the relative efficiency of all the countries included in the study. The nations have been ranked as per their relative efficiency and the peer group has been formed. Second a comparison between the rich and the poor countries have been done to test empirically whether the economic growth enhances the happiness among people. Presently, more than 3,000 studies have been published on happiness and Veenhoven in 2004 created a database called World Database of Happiness. The World Database of Happiness has attempted to present the available research findings on happiness. Part of the findings on happiness in nations is available in ‘States of nations’. For the research purpose, States of Nations and the data published by have been considered. Although happiness has been quantified and the existing literature has sufficient empirical evidences of the same, in the present context, the relative efficiency has been calculated for the countries on basis of objective and subjective happiness parameters. As per the literature, happiness has two aspects (1) objective and (2) subjective. Objective parameters are external to the individuals and covers material living parameters viz. GDP growth, income, nutrition, mortality rate, literacy etc. However, Subjective indicators measure the quality of life of the individuals. These are summarized as ‘‘subjective well-being’’. The various parameters considered in the study capture different aspects of happiness. The result shows how the government can increase the happiness of the people by analyzing the behavior and expectations. People express their preference explicitly about political parties, religion believes, law and order situation, trust in official institutions etc. Although, the behavior of people largely depends upon availability of goods and services in the market, the government can make budgets according to priority or preferences of people. Another way to increase happiness can be done by analyzing the peer group, which is an outcome of DEA. This shows the nations which are similar in terms of their economic and social conditions. The government can compare the prevailing conditions in different countries that improve the condition in their respective country. This could be an effective method as some of the parameters can be replicable in order to make people happier. The limitation of this study is lack of availability of data for many countries. As the number of countries increases, a change in the relative efficiency can be observed. Therefore, a future study can be conducted where the relevant data can be collected and a more global result can be obtained.     

Micro‐pensions in India: Issues and challenges

This article aims to fill a gap in the social security literature on India by examining the role of micro‐pensions. The analysis suggests that because of the heterogeneity of the target population, micro‐pension products — with microfinance institutions (MFIs) as the main, but not only sponsors — should be voluntary and portable and permit experimentation in their design and in the delivery of services. Accordingly, decentralized micro‐pension schemes that operate within an appropriate regulatory framework and according to sound governance practices are deemed more fitting for the Indian context than centralized schemes with limited flexibility. The article discusses two case studies of recently‐initiated micro‐pension schemes in India, which reveal the need for rigorous analytical research on the micro‐pension sector, particularly concerning the structuring of pay‐out options and innovative delivery mechanisms. The article concludes that micro‐pensions have the potential to be one of the most useful components in India's multi‐tiered social security system, and should be encouraged.