William E. Kastenberg

A methodology to integrate site characterization information into groundwater‐driven health risk assessment

A methodology is presented that incorporates site characterization information (in the form of hydraulic conductivity measurements) into a health risk assessment to individuals utilizing contaminated household water developed from groundwater sources. This methodology explicitly incorporates uncertainty (including the statistical parameter uncertainty arising from a limited number of hydraulic conductivity measurements) and variability (such as the variability in individual physiology) in all parameters, resulting in a nested Monte Carlo procedure. The methodology is demonstrated using a hypothetical case study where the sensitivity of various end points (including human health risk) to increased sampling of hydraulic conductivity are explored. It is shown that an increase in the number of measurements of hydraulic conductivity decreases the error in and uncertainty of predicted human health risk. Cost-benefit curves are developed and incorporated into a simple decision framework to determine the number of samples of hydraulic conductivity that are needed to accurately predict the human health risk from a contaminated site.

On the development of a new methodology for groundwater-Driven health risk assessment

A methodology and hypothetical case study are presented for incorporation of uncertainty and variability into calculations of human health risk appropriate for regional, or basin-scale, groundwater management problems. Uncertainty in well water concentration is introduced through complex contaminant migration patterns in the subsurface. Variability is considered in parameters related to individual behavior patterns and biological effects and to groundwater extraction and distribution networks. A joint uncertainty and variability (JUV) analysis is used to generate a two-dimensional distribution or risk surface that spans both transport uncertainty as well as individual variability. Cuts in this distributional surface (fractiles of variability and percentiles of uncertainty) are presented and discussed. Comparisons with alternative approaches based upon deterministic transport models are also made. In addition, important distinctions are made between the case where household water is derived from the nearest well and the case where household water is mixed from many wells in a distribution system.

A multimedia, multiple pathway risk assessment of atrazine: the impact of age differentiated exposure including joint uncertainty and variability

Abstract This paper addresses the need to evaluate the differences in exposure to pesticides between children and adults. We present a framework for evaluating these differences in exposure to pesticides through multiple exposure pathways. The concentrations in all environmental media were determined as distributions in a companion paper. All parameter values utilized in the calculation of exposure and risk are considered to be distributions, resulting in distributions for output exposure and risk. A sensitivity analysis was completed to determine the relative importance of the parameters with respect to the outcome. A joint uncertainty and variability analysis was also completed to evaluate the relative contribution between uncertain and variable parameters. Exposure to atrazine by a mid-western farming family is presented as a case study. The predicted exposure for a child based on a 14-year exposure period was 1.6 times that calculated using lifetime averaged exposure parameters. This indicates the importance of considering children as a population sub-group when calculating the exposure and risk to pesticides.

A multimedia, multiple pathway exposure assessment of atrazine: fate, transport and uncertainty analysis

Abstract The potential danger posed to human health from pesticides and herbicides has been a growing national concern due to the increased frequency of agrochemical residues found in food and water. It is becoming critical to determine the concentration in all environmental media for a complete picture of potential human exposure. A multimedia transport model is used to determine the concentration of atrazine in surface water, ground water, surface soil, root zone soil, plants, and air at a typical mid-western location. A range of values is used for each model input, resulting in a distribution of possible concentrations in each medium. A sensitivity analysis determines the influence each parameter has on the outcome variance for each environmental media concentration. The concentrations determined for ground and surface water are then compared to measured concentrations in the region to validate the model. The concentrations are then compared to measured concentrations in the region to validate the model. A companion paper utilizes these concentrations and translates them into human exposure and risk.

Regional scale framework for modeling water resources and health risk problems

A framework of simulation models for including human exposure to contaminants in regional scale aquifer management problems is presented. The framework includes horizontal flow and transport of contaminant plumes in the aquifer and multiple-pathway human exposure. Well water from the aquifer simulation model is used as the source of contaminant in the human exposure model. The exposure pathways considered for regional analysis are ingestion of foods grown using well water as part of the irrigation supply; ingestion and dermal absorption of contaminants in tap water; and inhalation of vaporized contaminants while bathing. An environmental compartment model is used to track the contaminant in irrigation water into the soil layers in contact with food products. The simulation framework is demonstrated in a study of the sensitivity of exposure to various aquifer and water supply parameters. The region used is hypothetical; however, the parameters are typical of California.

Industrial ecology and energy systems: a first step

This work is intended to contribute to the foundations for formalizing industrial ecology analyses of energy systems (systems for energy generation, transfer, or transformation) and to examine how the tools for performing these analyses can also enhance the field of industrial ecology in other applications. We discuss requirements for studying materials and energy cycling in industrial processes, with particular emphasis on energy generating systems, through explicit inclusion of entropy concepts in industrial ecology considerations. This perspective is intended to contribute to the theoretical basis for industrial ecology, to the development of tools for comparing the ecological (human and environmental health, and institutional) impacts of energy generating and other industrial processes, and to possible changes in engineering curricula with emphasis on design.

Hazards of Managing and Disposing of Nuclear Waste

Although it is arguably for the benefit of society, the translation of basic nuclear processes into technological achievements produces nuclear wastes that can become environmental hazards if they are not properly cared for. Light‐element fusion, heavy‐element fission and radioactive decay have provided us with nuclear weapons, nuclear power plants and nuclear medicine. But they all produce radioactive materials that are unusable, no longer needed, or unwanted. Ultimately, these materials require long‐term isolation from the biosphere.

Uncertainty and Regulation: The Rhetoric of Risk in the California Low-Level Radioactive Waste Debate

In this article, we analyze the intractability of the low-level radioactive waste debate in California through the construction and examination of policy frames and their associated policy narratives. Relying primarily on reports, formal comments, and written correspondence, we reconstruct three policy frames and explore their interaction in the public debate through the policy stories told by the actors. We analyze how policy actors using these policy frames appropriate available information, value scientific input, and respond to uncertainty in technical and regulatory information to create policy stories. These policy frames and their associated policy narratives demonstrate how policy actors differ in their drivers for action, bases for trusting claims, and response to uncertainty. These differences lead to divergent characterizations of the risk of low-level radio-active waste disposal. This analysis provides insight into the dynamics of intractable policy controversies.

Teaching global perspectives: engineering ethics across international and academic borders

Recent policy reports on responsible innovation emphasize the need to make ethics integral to advanced engineering programs. Students, however, usually perceive ethics as a set of rules and principles embedded in codes rather than as a set of open-ended approaches and a potential source of innovative research questions. We report on the pilot offering of an intensive summer program for graduate students, Global Perspectives: Engineering Ethics Across International and Academic Borders, which aimed to shift this perspective by creating opportunities for students to explore the challenging situation of ethics within graduate engineering education and specifically to engage in collaborative, interdisciplinary ethics research. By synthesizing scholarship from the philosophy of emotion, student voice, and early engagement, we aimed to create a space for student exploration, collaborative learning, and active knowledge production. The student commentaries that follow the article serve as the programs prelimina...

Science and uncertainty in environmental regulation: Insights from the evaluation of California's Smog Check program

Environmental decision making is a complex process confounded by technical uncertainty, political pressure, and social interests. New calls for environmental decision-making frameworks emphasize the need for an holistic approach that incorporates technical and non-technical expertise, and participation by all affected and interested parties. In this paper, we analyze the evaluation of an environmental regulatory program to characterize the interaction of science and policy and the processing of uncertainty using concepts from science and technology studies. This demonstrates the influence of institutional goals and commitments on the uptake and use of science and the processing of uncertainty in the regulatory process. We discuss the implications of such analyses on the development of new environmental decision-making frameworks.