Principles of risk decision-making.

Risk management decisions in public health require consideration of a number of complex, often conflicting factors. The aim of this review was to propose a set of 10 fundamental principles to guide risk decision-making. Although each of these principles is sound in its own right, the guidance provided by different principles might lead the decision-maker in different directions. For example, where the precautionary principle advocates for preemptive risk management action under situations of scientific uncertainty and potentially catastrophic consequences, the principle of risk-based decision-making encourages decision-makers to focus on established and modifiable risks, where a return on the investment in risk management is all but guaranteed in the near term. To evaluate the applicability of the 10 principles in practice, one needs to consider 10 diverse risk issues of broad concern and explore which of these principles are most appropriate in different contexts. The 10 principles presented here afford substantive insight into the process of risk management decision-making, although decision-makers will ultimately need to exercise judgment in reaching appropriate risk decisions, accounting for all of the scientific and extra-scientific factors relevant to the risk decision at hand.

Risk communication of endocrine-disrupting chemicals: improving knowledge translation and transfer.

Public perception of the negative effects of endocrine-disrupting chemicals appears to be higher compared to other chemical pollutants, due to (1) chronic, low-probability effects, and (2) uncertainties about which biological effects may be relevant for human health. Individuals, both expert and lay public, require credible, trustworthy, and understandable information about the scientific evidence of endocrine-disrupting chemicals in order to make informed risk decisions. The creation of a dedicated web site, http://www.emcom.ca, as a tool for knowledge translation and transfer provides the general public with access to scientific experts and bridges the gap between experts and nonexperts through a two-way, interactive communications approach. By obtaining accurate and credible information, individuals can make better-informed decisions concerning endocrine-disrupting chemicals.

Assessing and managing risks arising from exposure to endocrine-active chemicals.

Managing risks to human health and the environment produced by endocrine-active chemicals (EAC) is dependent on sound principles of risk assessment and risk management, which need to be adapted to address the uncertainties in the state of the science of EAC. Quantifying EAC hazard identification, mechanisms of action, and dose-response curves is complicated by a range of chemical structure/toxicology classes, receptors and receptor subtypes, and nonlinear dose-response curves with low-dose effects. Advances in risk science including toxicogenomics and quantitative structure-activity relationships (QSAR) along with a return to the biological process of hormesis are proposed to complement existing risk assessment strategies, including that of the Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC 1998). EAC represents a policy issue that has captured the public's fears and concerns about environmental health. This overview describes the process of EAC risk assessment and risk management in the context of traditional risk management frameworks, with emphasis on the National Research Council Framework (1983), taking into consideration the strategies for EAC management in Canada, the United States, and the European Union.

Men having sex with men donor deferral risk assessment: an analysis using risk management principles.

This article discusses issues associated with the lifetime deferral from donating blood of men having sex with men (MSM), in the context of well-established risk management principles, including ethical considerations associated with the risk-based approach to social policy matters. Specifically, it deals with the questions about the rationale for the existing policy in Canada of lifetime deferral for MSM, a rationale applied in practice by blood collection agencies and supported by the regulatory authority of Health Canada. We identify several alternative time frames for MSM deferral: sexual abstinence over either a 10-, 5-, or 1-year period or no deferral. Two options are selected for more complete discussion, namely, abstinence for a period of either 1 or 5 years before donation. The available evidence about estimated residual risk (RR)-that is, the risk remaining after various safeguards for blood are applied-strongly suggests that choosing a 1-year deferral period for MSM would almost certainly give rise to an incremental risk of transfusion-transmitted infection (TTI), over existing levels of risk, for blood recipients. The report argues that, under these circumstances, such a policy change would represent an unethical type of risk transfer, from one social group to another, and therefore would be unacceptable. The evidence is less clear when it comes to a change to either a 10- or 5-year deferral period. This is the case in part because the current level of RR is so low that there are, inevitably, substantial ranges of uncertainties associated with the risk estimation. There is no firm evidence that such a change in the deferral period for MSM would result in an incremental level of risk, although the possibility of a very small increase in risk cannot be entirely ruled out. Under these circumstances, other social policy issues, relevant to the idea of changing the deferral period for MSM, become worthy of additional consideration.

Effective risk communication practice.

Major public controversies over the management of health and environmental risks have been ongoing since the 1970s, starting with chemicals (pesticides and dioxins) and running through risks associated with many other industrial technologies. We can find in those controversies many common features, which cut across differences in both the technologies themselves and the types of risks they engender. This understanding also enables us to propose strategies to organizations to help them better respond to the public's needs (and the public interest) when concerns over risks arise. Effective risk communication practices are among the most important responsibilities for industry and governments in this regard. Since its origins in the late 1980s, risk communication practice has achieved a better understanding both of its goals and of how to achieve them. We are now in a position to specify with some precision what the fundamental requirements of good risk communication are, and they fall into three basic areas: (1) undertaking "science translation," (2) addressing uncertainties, and (3) dealing with the science/policy interface. Within these three areas there are a set of ten specific tasks, representing what may be called the minimum essential content requirements for every effective risk communication effort.

Risk management and precaution: insights on the cautious use of evidence.

Risk management, done well, should be inherently precautionary. Adopting an appropriate degree of precaution with respect to feared health and environmental hazards is fundamental to risk management. The real problem is in deciding how precautionary to be in the face of inevitable uncertainties, demanding that we understand the equally inevitable false positives and false negatives from screening evidence. We consider a framework for detection and judgment of evidence of well-characterized hazards, using the concepts of sensitivity, specificity, positive predictive value, and negative predictive value that are well established for medical diagnosis. Our confidence in predicting the likelihood of a true danger inevitably will be poor for rare hazards because of the predominance of false positives; failing to detect a true danger is less likely because false negatives must be rarer than the danger itself. Because most controversial environmental hazards arise infrequently, this truth poses a dilemma for risk management.

Health risks of electromagnetic fields. Part III: Risk analysis.

The management of potential health risks from electromagnetic (EM) fields presents both scientific and nonscientific challenges. When the scientific evidence is ambiguous, as is the case with EM fields, expert judgment of this evidence becomes particularly important. This article provides biomedical researchers with a comprehensive assessment of the status of EM health risk based on our two previous articles [Parts I and II, Critical Reviews in Biomedical Engineering, Volume 31, Issue 3]. Ambiguous evidence also necessitates rigorous public debate. This article also discusses effective risk communication approaches that play a key role in the EM risk issue. Because of uncertainty about health risks associated with EMF exposure, the public is more likely to experience difficulty in evaluating the available information and rely more on perceptions than facts when drawing conclusions. Even the most effective risk communication approaches are not likely to clarify all of the subtleties surrounding EM fields as a population health issue. Thus it is essential that all stakeholders involved in this issue participate in developing consensus solutions.

Health risks of electromagnetic fields. Part I: Evaluation and assessment of electric and magnetic fields.

Exposure to electric and magnetic fields (EMF) emanating from the generation, distribution, and utilization of electricity is widespread. The major debate in recent years has focused on the possibility that exposure to EMF may result in adverse health consequences, including the development of cancer. This article provides a review and evaluation of potential health risks associated with residential and occupational exposure to EMF. In addition to reviewing data from laboratory, epidemiology, and clinical studies, we examine exposure data from field measurement surveys and exposure guidelines that have been established for EMF. Currently, the evidence in support of an association between EMF and childhood cancer is limited, although this issue warrants further investigation. Evidence of an association between EMF exposure and adult cancers, derived largely from occupational settings, is inconsistent, precluding clear conclusions. There is little evidence of an association between EMF and noncancer health effects. Epidemiological studies of EMF and population health are limited by exposure measurement error and the lack of a clear dose/response relationship in studies suggesting possible health risks. Further research is needed to clarify the ambiguous findings from present studies and to determine if EMF exposure poses a health risk.

Health risks of electromagnetic fields. Part II: Evaluation and assessment of radio frequency radiation.

The increasing use of different radio frequency (RF)-emitting devices in residential and occupational settings has raised concerns about possible health effects of RF energy emitted by such devices. The debate about the potential risks associated with RF fields will persist with the prevalent network-connected wireless products and services targeting the marketplace for all kinds of consumer use. The aim of this article is to provide biomedical researchers with a review and critical evaluation of the current literature on acute and long-term health risks associated with RF radiation (RFR). Issues examined include safety standards for RFR; dosimetry and measurement surveys; and toxicological, epidemiological, and clinical studies of health outcomes that may be associated with RFR. Overall, the existing evidence for a causal relationship between RFR and adverse health effects is limited. Additional research is needed to clarify possible associations between RFR and biological effects noted in some studies. Particular attention should be directed toward long-term, low-level exposure to RFR.