Michael G. Tyshenko

The Impact of Social Amplification and Attenuation of Risk and the Public Reaction to Mad Cow Disease in Canada

Following the detection of bovine spongiform encephalopathy (BSE) in Canada, and subsequently in the United States, confidence in the safety of beef products remained high. Consumers actually increased their consumption of beef slightly after the news of an increased risk from mad cow disease, which has been interpreted as public support for beef farmers and confidence in government regulators. The Canadian public showed a markedly different reaction to the news of domestic BSE than the furious and panicked responses observed in the United Kingdom, Germany, and Japan. Using the social amplification of risk framework, we show that, while other countries displayed social amplification of risk, Canada experienced a social attenuation of risk. The attenuated reaction in Canada toward mad cow disease and increased human health risks from variant Creutzfeldt-Jakob disease (vCJD) was due to the social context at the time when BSE was discovered domestically. Mortality, morbidity, and psychosocial impacts resulting from other major events such as severe acute respiratory syndrome (SARS), West Nile virus (WNV), and the U.S.-Iraq war made the theoretical risks of BSE and vCJD a lower priority, reducing its concern as a risk issue.

Expert Elicitation for the Judgment of Prion Disease Risk Uncertainties

There is a high level of uncertainty surrounding the potential for iatrogenic prion transmission through transplantation, medical instrument reuse, blood transfusion, and blood product use due to a lack of evidence-based research on this important risk issue. A group of specialists was enlisted to evaluate some of the knowledge gaps in this area using the “Classical Model,” a structured elicitation procedure for weighting and pooling expert judgment. The elicitation exercise was undertaken in March 2009 with 11 transmissible spongiform encephalopathy (TSE) experts who were first calibrated using a series of seed questions for which the answers are known; they were then asked to answer a number of target questions that are important for risk assessment purposes, but for which there remains high uncertainty at this time. The target questions focused on variant Creutzfeldt–Jakob disease (vCJD) prevalence, incubation times for vCJD, genetic susceptibility to prion disease, blood infectivity, prion reduction of blood and blood products, surgical instrument risks, and interspecies transmission of TSEs. The experts were also asked to perform pairwise risk rankings for 12 different potential routes of infection. Dura mater transplantation was seen as having the highest risk, while dental tissue grafts were viewed as presenting the lowest risk of iatrogenic transmission. The structured elicitation procedure provides a rational, auditable, and repeatable basis for obtaining useful information on prion disease risk issues, for which data are sparse.

A risk management framework for the regulation of nanomaterials

Nanotechnology promises a plethora of benefits to society. Early research has established that some types of nanomaterials may be highly toxic to living systems, while others are seemingly inert. Nanotoxicology is a new field that has become the focus for risk assessment and management of nanomaterials. To address the potential risks either current chemical and particulate material regulations need to be modified to encompass the uniqueness of nanomaterial exposure or nanomaterials should be regulated as an entirely separate category of environmental agent. Policy makers in different jurisdictions are already formulating new risk management frameworks for nanotoxicology. A review of risk management frameworks reveals similarities and differences between the largest funders of nanotechnology (the USA, the European Union, and Japan). The use of a common, integrated risk management framework of the type proposed here will help reduce future trade barriers that may arise from differential nanotoxicity derived standards and variable nanotoxicology research results.

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.

Regulatory and Nonregulatory Strategies for Improving Children's Environmental Health in Canada

Epidemiological and toxicological studies established positive associations between environmental hazards and adverse child health outcomes, including cancer, learning disabilities, behavioral problems, developmental effects, low birth weight, and birth defects. The economic and societal costs associated with childrens environmental health disorders were estimated to be substantial. The existence of knowledge gaps, lack of capacity, and the jurisdictional overlap of childrens environmental health issues are some of the barriers that impede effective policy decision making. To improve childrens environmental health and reduce economic and societal costs, current legislative frameworks could implement a series of amendments. The main federal, provincial, and municipal legislation used to protect children in Canada, either explicitly or implicitly, is reviewed. Recommendations for improving the existing framework for protecting and strengthening childrens environmental health are proposed.

Expert judgement and re-elicitation for prion disease risk uncertainties.

Much uncertainty surrounds transmission of transmissible spongiform encephalopathies (TSEs) through blood and blood derived products. A first expert elicitation with 14 experts was conducted in March 2008, and a second re-elicitation involving 11 experts was held a year later in March 2009. Both expert groups were calibrated using a series of seed questions for which values are known, and then were asked to provide their individual judgements on a set of seven target questions for which values are not known or have not been determined through conventional research. Questions dealing with uncertainty of TSE prevalence, genotype effects, susceptibility, and infectivity were answered by the experts. Elicitation can be used to obtain quantitative values for parameters affecting prion uncertainty gaps. We show that the method is amenable to re-elicitation over time allowing refinement of expert opinion as new knowledge becomes available for improved risk assessments where data gaps continue to exist.

The risk to human islet cell transplant recipients of acquiring variant Creutzfeldt-Jakob disease: a provisional quantitative risk assessment.

different soluble (HLA-G5–HLA-G7) and membrane bound (HLA-G1–HLA-G4) isoforms may be involved in regulation of accommodation of different allograft types. Recently, only HLA-G1 isoform in peripheral blood mononuclear cells and biopsy samples was reported to have association with kidney allograft state (10). In summary, our results suggest that, unlike in liver transplantpediatricrecipients, serological monitoring for HLA-G levels in pediatric kidney transplant recipients may have limited benefit and poor correlation with the underlying phenotype of transplant injury, at least early after transplantation. Further studies should be targeted at serial analysis of soluble and membrane-bound HLA-G molecules later after transplantation to assess whether undulating levels of serum HLA-G can provide some direction for causality for the immunologically diverse outcomes after pediatric kidney transplantation and to evaluate and investigate the specific regulatory properties of HLA-G in organ transplantation.

Managing the risks of bovine spongiform encephalopathy: a Canadian perspective

This paper reviews the history of the risk management challenges faced by many countries and regions of the world which have had cases of bovine spongiform encephalopathy (BSE) from 1986 to the present. The paper first summarises the nature of prion diseases from a scientific perspective, and then presents an overview of the findings of an extensive set of country case studies, devoting special attention to the Canadian case. It derives from these studies the need to reconstruct the frameworks which have been guiding risk management decision making, using forma schemata based on a step-by-step approach. The paper presents and illustrates a revised format for an integrated risk management framework, including a set of specific and explicit objectives that should guide the use of this framework in practice, and concludes by raising policy issues that are currently outstanding with respect to the management of prion disease risks.

Applying a precautionary risk management strategy for regulation of nanotechnology

Nanotechnology promises a multiplicity of benefits to society. At the same time it has become a focus of debate regarding potential health and other associated risks. Rejection of new nanotechnology innovations could result in loss of trust in regulators, a phenomenon observed previously with nuclear and genetically altered food crop technologies. Due to this uncertainty a precautionary approach is warranted. The anticipated four stages of nanotechnology development, from passive to more active forms, are arrayed against existing risk management strategies of a precautionary nature. The overlay suggests that precaution is appropriate for all stages of nanotechnology development. Other effects from innovation, such as socio-economic inequity, disruptive impact on labour markets, alteration of global trade and unintended health and environmental impacts, can also be minimised by applying a precautionary approach. The use of a precautionary approach can provide protection to developers of nanotechnology, to individuals and to the environment.

Risk management for bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease in France: policy analysis and lessons learned

The experience of bovine spongiform encephalopathy (BSE) risk assessment and management in France was somewhat unique among BSE affected countries. Due to its proximity to the UK, the French meat and bone meal industry was challenged with particularly high amounts of infectivity from imported contaminated feed and infected cattle. Although France apparently had an adequate BSE control system before the epidemic, the lack of scientific knowledge about BSE transmission resulted in an underestimation of the economic and public health consequences of the disease. Consequently, preventive measures were often delayed and ineffectively implemented. As awareness of the impacts grew, more rigorous and effective measures eventually brought BSE under control. France has reported the largest number of variant Creutzfeldt-Jakob disease cases outside of the UK. However, measures have been implemented to control this disease in humans.