Traditional Hazard Research Articles

Abundance Estimation of Long‐Diving Animals Using Line Transect Methods

Line transect sampling is one of the most widely used methods for estimating the size of wild animal populations. An assumption in standard line transect sampling is that all the animals on the trackline are detected without fail. This assumption tends to be violated for marine mammals with surfacing/diving behaviors. The detection probability on the trackline is estimated using duplicate sightings from double-platform line transect methods. The double-platform methods, however, are insufficient to estimate the abundance of long-diving animals because these animals can be completely missed while the observers pass. We developed a more flexible hazard probability model that incorporates information on surfacing/diving patterns obtained from telemetry data. The model is based on a stochastic point process and is statistically tractable. A simulation study showed that the new model provides near-unbiased abundance estimates, whereas the traditional hazard rate and hazard probability models produce considerably biased estimates. As an illustration, we applied the model to data on the Baird's beaked whale (Berardius bairdii) in the western North Pacific.

The Office of Health Assessment and Translation: A Problem-Solving Resource for the National Toxicology Program

The Office of Health Assessment and Translation: A Problem-Solving Resource for the National Toxicology Program

Hazard Analysis and Validation Metrics Framework for System of Systems Software Safety

Safety-critical software-intensive systems of systems require rigorous verification and validation to ensure that they function as per requirements. Unlike verification, validation is typically an ill-defined activity for software development. This paper presents a well-defined validation metrics framework which uses hazard analysis, and the derived software requirements for mitigating the identified hazards, as proxies in gauging the sufficiency of the software safety requirements early in the software development process. Moreover, traditional hazard analysis techniques are insufficient to deal with the complexity and size of systems of systems. This paper examines the nature and types of hazards associated with systems of systems and presents a new technique for analyzing one type of emergent hazard known as an interface hazard.

Facilitating uncertainty treatment in the risk assessment of container supply chains

Over the last few years there has been a growing international recognition that Container Supply Chains (CSCs) contribute to economic prosperity. But they are uniquely vulnerable to many risks caused by both the traditional hazards, such as physical breaches in the integrity of shipments and the newly rising threats associated with pirate and terrorist attacks. To allow better understanding and control of the risks, it is necessary for the stakeholders to proactively assess the chains’ security and safety in advance, or reactively discover risks after a detrimental event occurs.This paper explores the various CSC risks, identifies common themes, and deals with the corresponding uncertainties by developing two novel risk modelling methods. One is to develop a fuzzy evidential reasoning approach for carrying out the security estimation of a vulnerable port system against terrorism attacks and the other is to produce a Bayesian network decision support tool for identifying vulnerable assets in a port security protection scenario. Consequently, the methods can be used to assemble and process subjective risk information on different aspects of a container transport system from multiple experts in a systematic way. Outcomes of the models can also provide decision makers with a transparent tool to evaluate CSC safety and security policy options for a specific scenario in a cost-effective manner.

The Price of Progress: Modern Environmental Health Hazards in Africa

With the spread of industrialization to all areas of the globe, scientists and policymakers alike have voiced mounting concerns over the ability of developing countries to limit the public health impacts of unchecked development. African nations, for example, have experienced rapid urbanization as well as tremendous expansion in industry and technology in an attempt to raise living standards and keep pace with the global community. But this trend has also exposed these nations to numerous modern environmental health hazards (MEHHs)—health threats that tend to accompany rapid development in the absence of health and environmental safeguards. A review of the scientific literature suggests that such hazards have added considerably to Africa’s disease burden and are increasing in public health significance [EHP 117:863–870; Nweke and Sanders]. The authors wrote that ongoing exposures to emerging MEHHs may soon rival the contributions of more traditional hazards—including malaria, poor access to safe drinking water, and lack of basic sanitation—that have long troubled Africa. Furthermore, poor and malnourished populations may be more vulnerable to the impacts of MEHHs, given that malnutrition increases susceptibility to toxicologic challenges. According to the United Nations Industrial Development Organization, Africa’s pollution intensity (pollution generated per unit of production output) is among the highest in the world. Reviewing published epidemiologic, exposure, and environmental studies of chemical agents, the researchers noted ongoing occupational and nonoccupational exposures to organochlorine pesticides such as DDT and to heavy metals such as lead and mercury. All these pollutants are known to persist in the environment and accumulate in the food chain over time, as confirmed by biomonitoring studies of farmworker populations in several African nations. The authors also presented evidence of existing and emerging air toxics issues related to both indoor and outdoor air pollution, pervasiveness of toxic chemicals in consumer products (such as arsenic and chromium in canned beverages), and inadequate management of domestic and industrial waste streams. Relatively robust exposure data for lead showed elevated body burdens in African populations exposed to lead-bearing soil, dust, and paint, offering suggestive evidence of ongoing exposures to MEHHs at biological levels associated with adverse health impacts. Some studies found elevated body burdens of mercury in exposed populations such as miners, workers involved in ore processing, children who resided in mining communities, and women who habitually used soaps that contain high concentrations of inorganic mercury (such soaps are marketed as skin and hair lighteners). However, very few body burden studies have provided conclusive evidence of the relationship between heavy metal exposures and increased disease risks in African populations. Management of MEHHs in many African nations has long been hampered by a lack of various safeguards for environmental health, such as stable institutions, adequate infrastructure, monitoring capacity, and regulatory frameworks. The researchers proposed that MEHHs should occupy a priority spot on Africa’s public health and policy agenda, and emphasized that future public health policy should consider these newer environmental health risks in tandem with other longstanding public health issues.

Predicting Probabilistic-Based Strong Ground Motion Time Series for Citadel of Arg-E-Bam (South-East of Iran)

The main objective of this article is to present a probabilistic-based strong motion compatible with the source-path and site soil condition given the probability of exceedence for citadel of Arg-e-Bam site bed rock (South-East of Iran). A Fourier amplitude spectral attenuation relation for bed rock beneath the site is proposed which permits the estimation of time-histories through a probabilistic seismic hazard analysis procedure. Due to lack of data, the two well-known simulation techniques, point source and finite fault models have been used for generating hundreds of strong motion as input data. Tens of model parameter values such as stress-drop nucleation points were used, in each specified magnitude-distance, to reduce the uncertainty effects inherently existing in seismological/geological parameters. The proposed attenuation relation is validated by comparing the estimated strong motion, in the form of Fourier amplitude spectral, using the proposed attenuation relation with those of recorded ground motion data at three stations far away from the assumed source so that the results would not be influenced by the near source problems such as directivity and fling step. The results of proposed technique is assessed by comparing the estimated response spectra, with 10% probability of exceedence and 5% damping ratio, with those of traditional uniform hazard spectra. The proposed technique is supposed to be used in retrofitting procedure of international historical adobe structures in Arg-e-Bam site, which have been damaged during the destructive Bam earthquake 2003, Iran

Accounting for Variation in the Explanatory Power of the Psychometric Paradigm: The Effects of Aggregation and Focus

Most psychometric studies of risk perception have used data that have been averaged over participants prior to analysis. Such aggregation obscures variation among participants and inflates the magnitude of relationships between psychometric dimensions and dependent variables such as overall riskiness. However, most studies that have not averaged data over participants have also shifted the focus of analysis from differences among hazards to differences among participants. Hence, it is unclear whether observed reductions in the explanatory power of psychometric dimensions result from the change in the level of analysis or from the change in the focus of analysis. Following Willis et al.'s (2005) analysis of ecological risk perceptions, we unconfound these two variables in a study of risk perceptions in Santiago, Chile, although we use more traditional hazards, attributes, and statistical procedures. Results confirm that psychometric dimensions explain less variation in judgments of riskiness and acceptability at the disaggregate level than at the aggregate level. However, they also explain less variation when the focus of analysis is differences among participants rather than differences among hazards. These two effects appear to be similar in magnitude. A simple hybrid analysis economically represents variation among participants' judgments of hazards' riskiness by relating those judgments to a common set of psychometric dimensions from a traditional aggregate‐level analysis.

Reduced Form Mortgage Pricing as an Alternative to Option-Pricing Models

This paper extends the traditional hazard technique of estimating prepayment and default by allowing their baselines to be stochastic processes, rather than known paths of time, as is typically assumed. By working in the reduced form, this method offers an alternative to the empirical valuation of mortgages more easily implemented than the standard structural form approach of options pricing.

Emerging Issues in Occupational Safety and Health

In developed countries, changes in the nature of work and the workforce may necessitate recalibrating the vision of occupational safety and health (OSH) researchers, practitioners, and policymakers to increase the focus on the most important issues. New methods of organizing the workplace, extensive labor contracting, expansion of service and knowledge sectors, increase in small business, aging and immigrant workers, and the continued existence of traditional hazards in high-risk sectors such as construction, mining, agriculture, health care, and transportation support the need to address: 1) broader consideration of the role and impact of work, 2) relationship between work and psychological dysfunction, 3) increased surveillance basis for research and intervention, 4) overcoming barriers to the conduct and use of epidemiologic research, 5) information and knowledge transfer and application, 6) economic issues in prevention, and 7) the global interconnectedness of OSH. These issues are offered to spur thinking as new national research agendas for OSH are considered for developed countries.

Frequency of Man‐Made Disasters in the 20th Century

AbstractThis paper analyses two disaster databases maintained by the Center for Research on the Epidemiology of Disasters and by Emergency Management Australia. The objective is to quantify the frequency, nature and changes in man‐made disasters in industrialised countries during the past century. The analysis shows an exponential growth in disaster frequency, largely due to an increase in traditional hazards such as fires and explosions, rather than from new technologies. Although the number of incidents has grown, this has been offset by a decline in fatalities per incident. An important implication of these results is that regulatory oversight and internal corporate governance processes are inadequate to ensure effective management of modern industrial risks.

An updated hazard vulnerability analysis: A value-based model

Traditional hazard vulnerability analysis (HVA) looks at probability and impact to determine risk. The results are often graphically displayed in an XY chart, and mitigation priorities are determined by risk ranking alone. This model is not sufficient, because it does not consider the cost of mitigation. The updated HVA looks at value, in which the traditional XY chart is expanded to a cube model in which the Z axis reflects cost. In a typical hospital HVA, where there may be over 50 different potential events, determining proximity to the perfect value point (high probability, high impact, low cost) allows a better ranking system when allocating scarce mitigation dollars.

3.2.3 An Approach to Design for Safety in Complex Systems

AbstractMost traditional hazard analysis techniques rely on discrete failure events that do not adequately handle software intensive systems or system accidents resulting from dysfunctional interactions between system components. This paper demonstrates a methodology where a hazard analysis based on the STAMP accident model is performed together with the system development process to design for safety in a complex system. Unlike traditional hazard analyses, this approach considers system accidents, organizational factors, and the dynamics of complex systems. The analysis is refined as the system design progresses and produces safety‐related information to help systems engineers in making design decisions for complex safety‐critical systems. The preliminary design of a Space Shuttle Thermal Tile Processing System is used to demonstrate the approach.

The effect of training on search durations: a random effects approach

After 7 months of search for apprentice vacancies, Danish vocational students are offered training. The training program has two purposes. One is to assist students in their search for apprentice vacancies and the other is to give the students the possibility of completing their education through the training program rather than through an ordinary apprenticeship. Thus, the training program may attract both students with low as well as high transition rates into apprentice vacancies. Controlling for observed as well as unobserved heterogeneity is therefore important when estimating the effect of the program. Empirically, it turns out that when applying a traditional hazard model, the training program is seen to decrease the hazard rate to apprenticeship vacancies. However, when correcting for selection bias by jointly modelling the allocation process to training as well as hazard rates to apprentice vacancies by a random effect model, the training program is seen to increase hazard rates significantly.

Air Quality as a Meteorological Hazard

Meteorological hazards are usually considered to be tropical cyclones, droughts, hail-storms, severe storms and their effects such as tsunamis, storm surges, wildfire, and floods. Urban air pollution is not normally considered to be a meteorological hazard. This view has arisen because the causes of urban air pollution – industrial and motor vehicleemissions – are not meteorological in nature. Air pollution episodes, however, are sporadic in nature and their occurrence depends on a particular combination of meteorological factors. This is true even in megacities such as Mexico City, Manila, and Los Angeles that have acquired a reputation for polluted air. Analyses of air pollution episodes and hospital admissions from many countries indicate that thereis a significant increase in morbidity and mortality as a result of such episodes.Time-series studies undertaken in Sydney have shown that particulate matter, ozone and nitrogen dioxide are the pollutants that are primarily responsible for adverse health effects in that city. Air pollution, and in particular particulate matter, is believed to be responsible for just under 400 premature deaths per year in Sydney alone. This death rate is over twenty times larger than deaths due to other meteorological hazards. Part of the reason for the low death rate for the more traditional meteorological hazards is that the provision of high quality numerical weather prediction, coupled with modern communications technology, has enabled emergency service personnel to take appropriate action. Air quality forecasting systems can play an important role in mitigating the adverse effects of air pollution. The forecasts will affect the behaviour of susceptible individuals, and thus reduce adverse health effects. The outputs from forecasting systems can also be used to provide improved estimates of the total exposure to air pollutants of the inhabitants who areat risk. Such improved estimates can then be used in conjunction with longitudinal studies ofhealth effects to obtain better understanding of the complex interaction between air quality and health.

Participative Approaches for Evaluating the Hazards of New Technology

New technology is transforming the workplace and bringing with it hazards that were unknown a few decades ago. New chemicals, plasma gases, biotechnology, new electronic devices, robots, and genetic engineering are being introduced so quickly that we do not know if they pose new threats to health until after they have been in wide use. These new technologies challenge our current state of knowledge about health hazards and our ability to control potential hazards. A major concern is that there currently are not enough resources to handle traditional safety and health hazards, and that these new challenges will tax the capabilities of our current health and safety resources. It is very likely that the potential hazards posed by new technology may not be amenable to traditional safety and health approaches. A major difficulty is that we just do not have enough knowledge about these new technologies or their potential harmful effects to be able to make good judgments. Knowledge about potential health hazards is lacking, and because these technologies have only been around a short time, epidemiological evidence on long term health effects is not available. Our challenge then is to develop new hazard assessment and surveillance methods to deal with emerging technologies. Participative approaches hold promise for successful programs.

TUNING OF SEISMIC HAZARD ESTIMATES BY MEANS OF OBSERVED SITE INTENSITIES

Probabilistic seismic hazard is usually assessed by means of computer codes using seis-mogenic sources, parametric catalogues, seismicity rates and attenuation relationships. All these ingredients are conditioned by expert judgement that influences the final results. Even the attenuation relationships, though strictly based on experimental data, are considered a weak point due to the difficulty of modelling the interaction between seismic energy radiation and site response, and because earthquakes do not usually repeat themselves according to one theoretical model. Recently, methods making wide use of site intensity data have been developed in regions such as Italy, where the observed seismic history at selected sites is quite exhaustive. We analyzed these observations to assess seismic hazard at about 600 sites. We used a probabilistic counting technique, integrating the observations (when necessary), with computed shakings obtained from a logistic-type attenuation model. The results were then compared with the estimates provided by the recent seismic hazard map of Italy, compiled according to the traditional probabilistic seismic hazard approach. The match shows significant differences for some sites. A tentative explanation which seems to point to three alternatives is provided: (1) The mismatch between the two methodologies might appear because the stationary assumption has a poor fit with reality (at least in certain areas); (2) Some sites show a response that is systematically different from the average values predicted using attenuation relationships; (3) The definition of seismogenic zones leads to a bias in the seismicity rate estimate.

Estimation of surgeon effects in the analysis of post-operative colorectal cancer patients data

There has been increasing interest in the assessment of surgeon effects for survival data of post-operative cancer patients. In particular, the measurement of surgeon's surgical performance after eliminating significant risk variables is considered. The generalized linear mixed model approach, which assumes a log-normal-distributed surgeon effects in the hazard function, is adopted to assess the random surgeon effects of post-operative colorectal cancer patients data. The method extends the traditional Cox's proportional hazards regression model, by including a random component in the linear predictor. Estimation is accomplished by constructing an appropriate log-likelihood function in the spirit of the best linear unbiased predictor method and extends to obtain residual maximum likelihood estimates. As a result of the non-proportionality of the hazard of colon and rectal cancer, the data are analyzed separately according to these two kinds of cancer. Significant risk variables are identified. The 'predictions' of random surgeon effects are obtained and their association with the rank of surgeon is examined.

Human adjustments and social vulnerability to volcanic hazards: the case of Furnas Volcano, São Miguel, Açores

Abstract Following a review of recent developments by social theorists, concerned with the policy and practice of natural hazard reduction it is argued that neither the so-called dominant nor the radical perspectives, are sufficient on their own to answer the questions now being addressed by applied volcanologists during the International Decade for Natural Disaster Reduction. In order to make useful recommendations to policy-makers, which are both reliable assessments of eruption risk and at the same time sensitive to probable interactions of future eruptions with the physical environment of the study region and its peoples, a conflation of traditional hazard analysis and vulnerability analysis is required. This view is tested by means of a case study of evacuation planning at Furnas Volcano in the Açores. As well as supporting the argument from theory, this example leads to the proposition that research on evacuation planning and civil defence should proceed in an ordered sequence. First hazard analysis (i.e. hazard mapping) should be carried out in the traditional manner. Next possible interactions with the physical environment should be specified and a preliminary plan of evacuation routes drawn up. Before detailed recommendations about the logistics of evacuation are made, however, it is vital that such factors as the demographic, socio/economic and cultural/behavioural characteristics of the population at risk are fully considered.

The 1998 Donald E. Cummings Memorial Award Lecture. The industrial hygiene paradox, dilemmas, and a vision for the future.

How do we move from diatribe to dialogue? Since the Donald E. Cummings Award was first established in 1943, the profession of industrial hygiene has seen many changes. The traditional hazards Alice Hamilton addressed in her 1948 Cummings lecture have been controlled. However, the advent of the Occupational Safety and Health Administration (OSHA) has changed the approach of many of today's industrial hygienists from "best professional practices" to regulatory compliance or OSHA industrial hygiene. Further, the dialogue that has existed between academia, business, government, and labor that allows industrial hygienists to identify and resolve health hazards is now threatened by lawsuits and lobbyists. Industrial hygienists have a professional responsibility to workers, employers, clients, and the public. Our vision for the future must refocus on this responsibility as we once again embrace dialogue instead of diatribe. This lecture was presented at the American Industrial Hygiene Conference and Exposition in Atlanta, Ga., on May 13, 1998.

Strategic risk assessment—prioritising environmental protection

Environmental protection and improvement comes at a price, and regulators must ensure that resources are targeted at the highest priority risks. Risk assessment at a strategic level is now an essential tool. Risks can arise from natural sources such as flooding and radon, as well as anthropogenic sources such as discharges of pollutants or the introduction of alien fish species. In deciding which environmental pressure to tackle next, and which to leave, regulators have to compare the full range of risks on a sound and consistent basis. Comparing risks from such diverse sources poses a significant challenge and traditional hazard assessments are now no longer sufficient. Consideration now needs to be given to a much wider range of factors if risk assessment is to be used as an aid to strategic decision-making. In general, Strategic Risk Assessment can be broken down into four main tasks. (i) Harm assessment—where the impact of a given level of exposure on a predefined receptor group is determined. (ii) Risk significance—where the harm evaluated in (i) is placed in the geographical ( regional, national, international) context in relation to the overall population of receptors, and the range of different receptors. (iii) Risk uncertainty—where the probability of occurrence, exposure and harm is quantified together with the range of uncertainties involved in the overall assessment. (iv) Risk importance—where the costs and benefits of various actions/options together with a measure of society's view of the risk are brought together. All the above have been included in the Strategic Risk Assessment Methodology which has been developed by the Environment Agency, and will be used to direct the organisation's manpower and financial resources to maximise its contribution to sustainable development.