Principles Of Risk Assessment Research Articles

Basic Principles of Workplace Risk Assessment and Control/Guidelines for the Smaller Contractor

Basic Principles of Workplace Risk Assessment and Control/Guidelines for the Smaller Contractor

The role of pre-release efficacy assessment in selecting classical biological control agents for weeds—applying the Anna Karenina principle

The goals in selecting classical biological control agents for weeds are to identify agents that will be both safe for release and effective in controlling their target plants. The release of ineffective agents should be avoided, as these add to the costs and risks of biological control without contributing to its benefits. While the principles of host-specificity testing and risk assessment for weed biological control agents have been extensively debated and refined, there has been less attention given to assessing the probable efficacy of agents prior to release. This reluctance to undertake pre-release efficacy assessment (PREA) is probably based on concerns that it will both add to the cost of screening biological control agents and introduce a risk of wrongly rejecting effective agents. We used a project simulation model to investigate the implications of using PREA as an additional filter in the agent selection process. The results suggest that, if it can be done at a lower cost than host-specificity testing, the use of PREA as the first filter can make agent selection more cost-effective than screening based on host-specificity alone. We discuss examples of PREA and potential approaches. The impact of biocontrol agents is a function of their range, abundance, and per-capita damage. While it will always be difficult to predict the post-release abundance of biological control agents from pre-release studies, some estimates of potential range can be obtained from studies of climatic adaptation. For agents that affect the vegetative growth or survival of their target weeds, experimental measurement of per-capita damage is feasible and can contribute to a reduction in the numbers of ineffective agents released. The Anna Karenina principle states that success in complex undertakings does not depend on a single factor but requires avoiding many separate causes of failure. We suggest that, in biological control of weeds, the use of agents that are not sufficiently damaging is one such cause that can be partially avoided by the use of pre-release efficacy assessment.

Biosafety evaluation of recombinant live oral bacterial vaccines in the context of European regulation

Live bacterial vaccines represent a highly valid preventive strategy in the fight against infectious disease. However, the road from research to market is peppered with hurdles, one of which is the requirement for high biosafety characteristics, which the candidate vaccine has to display. In Europe, the European Agency for the evaluation of medicinal products (EMEA) is the relevant authority regulating the licensure of genetically engineered vaccines. For this purpose, the agency may rely on several directives and guidelines defined in the past 15 years. As for live vaccines containing genetically modified organisms (GMOs) susceptible to be released into the environment, Directive 2001/18/EC determines the framework and principles of an environmental risk assessment (ERA) process, the results of which constitute an important section of the vaccine registration package submitted to registration authorities. In this article, we address the implications of current European regulations for the approval of live oral bacterial vaccines with emphasis on the assessment of potential risks associated with environmental release. Biosafety aspects of already registered and some promising live bacterial vaccine strains will be briefly discussed.

Improving the TMDL Process Using Watershed Risk Assessment Principles

Ecological risk assessment (ERA) evaluates potential causal relationships between multiple sources and stressors and impacts on valued ecosystem components. ERAs applied at the watershed scale have many similarities to the place-based analyses that are undertaken to develop Total Maximum Daily Loads (TMDLs), in which linkages are established between stressors, sources, and water quality standards, including support of designated uses. TMDLs focus on achieving water quality standards associated with attainment of designated uses. In attempting to attain the water quality standard, many TMDLs focus on the stressor of concern rather than the ecological endpoint or indicators of the designated use that the standard is meant to protect. A watershed ecological risk assessment (WERA), at least in theory, examines effects of most likely stressors, as well as their probable sources in the watershed, to prioritize management options that will most likely result in meeting environmental goals or uses. Useful WERA principles that can be applied to TMDL development include: development and use of comprehensive conceptual models in the Problem Identification step of TMDLs; use of a transparent process for selecting Numeric Targets for TMDLs based on assessment endpoints derived from the management goal or designated use under consideration; analysis of co-occurring stressors likely to cause beneficial use impairment based on the conceptual model; use of explicit uncertainty analyses in the Linkage Analysis step of TMDL development; and frequent stakeholder interactions throughout the process. WERA principles are currently most applicable to those TMDLs in which there is no numeric standard and, therefore, indicators and targets need to be developed, such as many nutrient or sediment TMDLs. WERA methods can also be useful in determining TMDL targets in situations where simply targeting the water quality standard may re-attain the numeric criterion but not the broader designated use. Better incorporation of problem formulation principles from WERA into the TMDL development process would be helpful in improving the scientific rigor of TMDLs.

Pesticide Spraying and Health Effects

I noticed with interest the article “Pesticide Spraying for West Nile Virus Control and Emergency Department Asthma Visits in New York City, 2000” by Karpati et al. (2004). I am a physician who treats hundreds of patients with chronic illness from chemical overexposure. Many of these patients have toxic encephalopathy, reactive airway disease, and other chemically induced organ system damage. When my patients become ill from pesticide spraying, they usually do not head for an emergency room, where they typically experience long waits in an environment containing germicidal residue, scented products, carbonless copy paper, hospital linens with heavy fabric softener, and other exposures. In addition, they have learned from experience that emergency department personnel often do not understand their condition and do not know how to treat it. Thus your survey, while with admirable intent, greatly underestimates the problem of respiratory exacerbation from West Nile virus pesticide use. Many of my patients have experienced severe neurologic and respiratory exacerbations as well as other organ system damage, such as significant increase in liver enzymes, from exposure to residue from pesticide spraying for West Nile virus. In addition, it is my understanding that these pesticides are not effective for controlling adult mosquitoes and that the Centers for Disease Control and Prevention and other authorities recommend larvae control. The extent of exacerbation of illness caused by pesticide use for West Nile virus control is likely greater than the number of cases of West Nile virus. Persons who are at increased risk for symptom exacerbation from pesticide spraying such as that used for West Nile virus control include individuals with migraines, chronic sinus problems, asthma, reactive airway disease, autoimmune diseases (many of which are exacerbated by pesticide exposure), and conventional allergies (Kipen et al. 1994). There is increased respiratory inflammation with conventional allergies, and pesticides more readily enter the body because the barrier function of the respiratory tract is further compromised. In addition, Karpati et al. (2004) failed to take note of the U.S. Environmental Protection Agency (EPA) final report “Principles of Neurotoxicity Risk Assessment” (U.S. EPA 1994). This document confirmed the lack of a blood–brain barrier between the nose and the brain, so that pesticides readily enter the body through the nose and pass directly to the brain. This report further confirmed the unusual vulnerability of the brain to neurotoxicants: pesticides are lipophilic and therefore seek out lipid tissue such as the brain, and because the brain has unusually long neurons, repair of damage in the neurons occurs much less readily than in other body cells. Other groups at increased risk of pesticides are those with chronic obstructive lung disease, toxic encephalopathy, and neural degenerative diseases. Pyrethroid pesticides are significant neurotoxins (Eells et al. 1992; McDaniel and Moser 1993; Tippe 1993; Vijverberg and van den Bercken 1990), and because they are increasingly replacing organophosphates, they now account for a large proportion of the pesticide-induced chronic illness among my patients. Emergency room visits are merely the tip of the iceberg, and patients with many of these disorders usually avoid the emergency room. Thus, the use of emergency rooms is not a sensitive indicator of body damage from pesticides. In my experience, the use of nebulized glutathione, the major antioxidant and major detoxifying agent of the body (Klaassen et al. 1986), when combined with lipoic acid, helps to improve an individual’s ability to detoxify (Packer et al. 1995); lipoic acid reactivates glutathione in lipid-and water-based tissues. Also, nebulized glutathione combined with adequate buffered vitamin C reactivates glutathione in water-based tissues.

The U.S. environmental protection agency's examination of its risk assessment principles and practices: A brief perspective from the regulated community

In March 2004, the U.S. Environmental Protection Agency (U.S. EPA) published a review of its risk assessment principles and practices. In examining this review, we find a broad, but not particularly deep, review by the authors and areas where the U.S. EPA should strive to further improve the risk assessment process. Recommended areas of improvement include the use of less conservative default assumptions, calculating risk based on populations instead of individuals, and fostering research on multiple stressors and their impacts on estimating risks to ecological receptors.

The future direction of ecological risk assessment in the united states: Reflecting on the U.S. environmental protection agency's “examination of risk assessment practices and principles”

As part of an agency evaluation of the development of risk assessment tools, the U.S. Environmental Protection Agency (U.S. EPA) issued a staff paper in March 2004 describing the current state of practices and policies regarding risk assessment from the agency's perspective. The staff paper provided a rationale for the agency's positions regarding technical topics frequently the subject of comments or complaints. Considerations relevant to ecological risk assessment were included, primarily in a single chapter focused on this topic. This commentary highlights four technical issues important to the advancement of ecological risk assessment practice and discusses how some of the points raised by the U.S. EPA in the staff paper have significance to ecological risk assessors. Discussion regarding incorporating population- and community-level analysis into risk assessments and the apparent reluctance of the U.S. EPA to adopt advances in this area is provided. Also, continuing inconsistencies in the body weight scaling of toxicity values between human health and ecological risk assessment practices are discussed. Ideas for refining the calculation of exposure point concentrations for ecological receptors and the progression between screening steps and comprehensive risk assessment are also discussed.

Protecting native americans through the risk assessment process: A commentary on “an examination of U.S. EPA risk assessment principles and practices”

Protecting native americans through the risk assessment process: A commentary on “an examination of U.S. EPA risk assessment principles and practices”

Risk Assessment in Psychiatric Practice

Every day, clinicians assess risk in various settings. Psychiatrists in all forms of practice are asked to use their skills to forecast the risk of violence: Is the patient dangerous? Should the patient be detained against his or her will? When can we safely release the patient into the community? These are just a few of the formidable questions that are asked daily in clinical practice. Given these expectations, how are we to navigate the inherent uncertainties of risk assessment? Providing didactic education and clinical training for residents within the core psychiatric curriculum would seem essential. Continuing professional development is equally important for psychiatrists to remain well informed of developments in the field. This issue’s In Review section highlights many developments, both in Canada and internationally, along with their clinical implications. The first article, by Dr Hy Bloom and colleagues, gives us a historical overview and suggests implications for current psychiatric practice from a Canadian perspective (1). Canadians have contributed significantly to the international literature on risk assessment, and Bloom and colleagues highlight the importance of assessing the risk of violence to others. They describe this as “undoubtedly the most essential and onerous risk decision-making area (civil commitment) for psychiatrists,” and offer psychiatrists contemporary risk assessment principles to guide clinical practice. The second article, by Dr Graham Glancy and Dr Gary Chaimowitz, provides an overview of the clinical use of risk assessment (2). These authors argue that risk assessment should be part of daily clinical psychiatric practice—indeed, not only risk assessment but, more importantly, risk management and risk reduction. Glancy and Chaimowitz advocate for the use of as much information as possible, including clinical (dynamic), historical (static), and collateral information. This in turn allows clinicians to consider the imminence and severity of potential violence, under what circumstances this risk will be increased, and what can be changed to reduce the risk.

Mode of Action: Reduction of Testosterone Availability—Molinate-Induced Inhibition of Spermatogenesis

Molinate is a preemergent herbicide that has been demonstrated to affect reproduction in the rat via alterations in sperm production. A wealth of standard toxicological studies and targeted research efforts relating to this adverse effect is available, and these were used to evaluate the utility of the Human Relevance Framework (HRF) for noncancer health effects. The hypothesized mode of action involved inhibition of the hydrolysis of cholesterol from high-density lipoprotein in the rat testes, followed by an androgen withdrawal syndrome on spermatogenesis. Some evidence is available that a similar mode of action would not be operable in humans. Despite the wealth of studies conducted in the rat, the weight of evidence is insufficient to define the mode of action for reproductive toxicity in the male rat. A principal deficiency in the database was discordance between the exposure levels observed to cause biochemical disturbances in the testes related to the hypothesized mode of action and the dose levels observed to induce the adverse outcome on spermatogenesis. For this reason, a complete MOA/human relevance analysis is not possible and, based on traditional risk assessment principles, any toxic effects are assumed to be relevant for human risk assessment.

Ecological risk assessment issues identified during the U.S. environmental protection agency's examination of risk assessment practices

Recently, the U.S. Environmental Protection Agency examined its current risk-assessment principles and practices. As part of the examination, aspects of ecological risk-assessment practices were reviewed. Several issues related to ecological risk assessment were identified, including the use of organism-level versus population-level attributes to characterize risk, the possible opportunities associated with the increased use of probabilistic approaches for ecological risk assessment, and the notion of conservatism in estimating risks. The agency examination provides an understanding of current practices and is intended to begin a dialogue in which the risk assessment community can engage in addressing the identified issues to improve and enhance ecological risk assessment.

Characterization of environmental risk of genetically engineered (GE) organisms and their potential to control exotic invasive species

Genetically engineered (GE) organisms could result in ecological harm in many ways in natural environments. Ecological harm can be assessed based on standard principles of risk assessment. Risk is the probability of harm as a result of a hazard, which in this case is a GE organism; its harm may not be known or knowable a priori, however, due to the large number of biotic interactions in nature in which it could be involved. We contend that for a GE organism to be a risk, it must be able to spread in nature. Thus, we do not have to determine all, or any, possible harms; we only need to be certain the organism will not spread if it escapes. Predicting the potential of a GE organism to spread is possible because the ultimate fate of a transgene will be determined by natural selection. Thus, environmental risk assessment can be accomplished by measuring six net fitness components that are common to all organisms, transgenic or wild type: juvenile and adult viability, fecundity, fertility, age at sexual maturity, and mating success. These components can be measured in secure settings. Previously, we focused on the environmental risk posed by GE organisms created to enhance agricultural productivity. Here we review the potential of using GE biotechnology for biological control of an existing undesirable exotic species. GE biological control might be employed to induce a ‘Trojan gene effect’ (Muir and Howard, 1999; 2002a,b) to eliminate such species, by introducing genes which cause male-biased sex ratios, inducible fatality, or selfish gene effects.

Principles of risk assessment for determining the safety of chemicals: Recent assessment of residual solvents in drugs and di(2‐ethylhexyl) phthalate

Risk assessment of chemicals is essential for the estimation of chemical safety, and animal toxicity data are typically used in the evaluation process, which consists of hazard identification, dose-response assessment, exposure assessment, and risk characterization. Hazard identification entails the collection of all available toxicity data and assessment of toxicity endpoints based on findings for repeated dose toxicity, carcinogenicity or genotoxicity and species-specificity. Once a review is compiled, the allowable lifetime exposure level of a chemical is estimated from a dose-response assessment based on several measures. For non-carcinogens and non-genotoxic carcinogens, the no-observed-adverse-effect-level (NOAEL) is divided by uncertainty factors (e.g. with environmental pollutants) or safety factors (e.g. with food additives) to derive a tolerable daily intake (TDI) or acceptable daily intake (ADI), respectively. These factors include interspecies and individual differences, duration of exposure, quality of data, and nature of toxicity such as carcinogenicity or neurotoxicity. For genotoxic carcinogens, low dose extrapolation is accomplished with mathematical modeling (e.g. linearized multistage model) from the point of departure to obtain exposure levels that will be associated with an excess lifetime cancer risk of a certain level. Data for levels of chemicals in food, water and air, are routinely used for exposure assessment. Finally, risk characterization is performed to ensure that the established 'safe' level of exposure exceeds the estimated level of actual exposure. These principles have led to the evaluation of several existing chemicals. To establish a guideline for residual solvents in medicine, the permitted daily exposure (PDE), equivalent to TDI, of N,N-dimethylformamide was derived on the basis of developmental toxicity (malformation) and of N-methylpyrrolidone on the basis of the developmental neurotoxicity. A TDI for di(2-ethylhexyl)phthalate was derived from assessment of testicular toxicity.

Real-time testing of foods: the Holy Grail?

The approach to quality assurance and control in the food industry has changed, especially with the widespread implementation of preventative, process-oriented food safety plans grounded in Hazard Analysis Critical Control Point (HACCP) and risk assessment principles. However, microbiological analysis of foods remains critical to the management of quality and safety of food products, particularly with respect to the detection of pathogens. The time to complete tests has decreased significantly but, the required sensitivity of the test, the physiological state of the target analyte, the food matrix and associated non-target microflora, all constrain further acceleration of testing and limit the potential for achieving real-time testing of foods, particularly when testing for pathogens such as Salmonella. While real time testing may be the ultimate goal, is it food microbiology?s Holy Grail?

The “Red Book” and Other Risk Assessment Milestones

Risk assessment as a regulatory tool developed during virtually all of the 20th century. During this period there were several critical events such as the passage of the Food and Drug Acts of 1906 and 1938 and the publication of the National Research Council's report Risk Assessment in the Federal Government: Managing the Process, known as the “Red Book,” which defined the concepts and principles of risk assessment. This paper reviews the impact of some of the major events in the evolution of risk assessment and concludes with some speculation on the future.

719 Principles of risk assessment of complex and combined action of pesticides

719 Principles of risk assessment of complex and combined action of pesticides

La rénovation du système français d'analyse des risques sanitaires

After several decades of gradual improvement in its system for managing health risks, France was confronted in 1996 with the bovine spongiform encephalopathy crisis. This triggered a collective questioning, which highlighted the need to reform a system that had shown its limitations. Risk analysis, established as a key principle by the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) of the World Trade Organization (WTO), was cast as the necessary basis of the reform, objectives of which were to better identify priority risks in order to ensure the protection of human and animal health, and to improve the quality of measures implemented by the public authorities. The Act of 1 July 1998 founded several independent risk assessment agencies, including the French Agency for Food Safety (AFSSA), with the specific mandate of food safety at every stage of the food chain. Other organisational reforms enhanced the new system, notably the separation between the functions of risk management and economic support for food industries, initially at central level, then in 2002 at the level of field services in the 100 French départements. Lastly, new procedures were introduced. These were designed, in accordance with the principles of risk assessment, to better identify and to individualise the different decision-making sequences. The decision-making process was extended to include submission to the agency in charge of evaluating health risks and examination by the agency of the resulting draft decision.

Le principe de précaution et ses implications juridiques dans le domaine de la sécurité sanitaire des aliments

The concept of the 'precautionary principle' is not independent of the general principles of risk assessment and cannot be used as a justification for circumventing the legal obligations established at international level by World Trade Organization (WTO) agreements. On the contrary, the principle, which allows policy-makers to act without waiting until all the relevant scientific information is available, is included in the discipline established by the WTO Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) and confirmed by jurisprudence. Sanitary measures adopted provisionally in a context of scientific uncertainty should nevertheless endeavour to comply with the general principles of risk management established by the SPS Agreement, i.e. they should be appropriate, non-discriminatory, consistent and not more trade-restrictive than required. The Codex Alimentarius has been working for several years to develop a set of principles for the application of risk assessment, including the precautionary principle when information is insufficient or incomplete. These principles will serve as a guide first for the work of the Codex and subsequently for governments. The European Union has made provision for the application of the precautionary principle, in accordance with circumstances, in Community food legislation, while remaining in compliance with the legal obligations stemming from the SPS Agreement.

Risk Assessment Applications Beyond Baseline Risks and Clean-Up Goals

Historically, the phrase “Risk Assessment” brought to mind a thick Superfund-type baseline risk assessment or clean-up goal derivation document filled with pages of tables with endless seemingly unrelated algorithms and numbers. Over the last decade, the principles of risk and exposure assessment have gained wide-reaching acceptance and are increasingly utilized to help solve other environmental impact, occupational health, or risk mitigation design problems. The typical objective of the classic risk assessment is the evaluation of current or future risks from exposure to contaminated media within the framework of a regulatory waste management or remediation program. Risk-based techniques are increasingly being used on a voluntary basis (i.e., outside of the standard regulatory arena) to demonstrate the presence, absence, or extent of environmental or health-related concerns in specific exposure circumstances. Likewise, a risk or exposure evaluation may be useful in determining the need for, or the legitimacy of, a public health advisory, alone or in conjunction with remedial or mitigative actions. Finally, risk-based techniques often find their way into the courtroom. Three case studies are presented in which riskbased solutions were employed to assist in resolving environmental or health-related issues: (1) a reversal of a fish consumption advisory; (2) an evaluation of arsenic in soil on and adjacent to a school facility; and (3) a challenge to a case of alleged methyl bromide exposure in a litigation context. In each case, the use of risk assessment principles was employed beyond the classic baseline risk assessment to address an applied problem of toxicological significance.

Truck driver fatigue risk assessment and management: a multinational survey

As part of an organizational review of safety, interviews and questionnaire surveys were performed on over 700 commercial goods drivers and their managers within a series of related companies operating across 17 countries. The results examine the reported incidence of fatigue-related problems in drivers and their associations with near miss and accident experience as well as work and organizational factors. Experience of fatigue problems while driving was linked to time of day and rotation of shifts, though most associations were small. There were significant associations found between fatigue experiences and driver and management systems of break taking and route scheduling. The quantitative combined with qualitative information suggested that, where feasible, more flexible approaches to managing the scheduling and sequencing of deliveries assisted drivers in managing their own fatigue problems through appropriate break-taking. The results are interpreted within the overarching principles of risk assessment and risk control.