Khara Deanne Grieger

Environmental risk analysis for nanomaterials: Review and evaluation of frameworks

Abstract In response to the challenges of conducting traditional human health and ecological risk assessment for nanomaterials (NM), a number of alternative frameworks have been proposed for NM risk analysis. This paper evaluates various risk analysis frameworks proposed for NM based on a number of criteria. Among other results, most frameworks were found to be flexible for multiple NM, suitable for multiple decision contexts, included life cycle perspectives and precautionary aspects, transparent and able to include qualitative and quantitative data. Nevertheless, most frameworks were primarily applicable to occupational settings with minor environmental considerations, and most have not been thoroughly tested on a wide range of NM. Care should also be taken when selecting the most appropriate risk analysis strategy for a given risk context. Given this, we recommend a multi-faceted approach to assess the environmental risks of NM as well as increased applications and testing of the proposed frameworks for different NM.

The known unknowns of nanomaterials: Describing and characterizing uncertainty within environmental, health and safety risks:

Various stakeholders have acknowledged that uncertainty within determining the potential environmental, health and safety (EHS) risks of nanomaterials (NM) may inhibit nanotechnology from reaching its full potential. A thorough description of such uncertainties is an imperative first step towards closing knowledge gaps and prioritizing research strategies. Through a qualitative uncertainty analysis which systematically screened 31 reports and articles published by leading scientists and authorities on the potential risks of NM, we found that knowledge gaps pervade nearly all aspects of basic EHS knowledge, with a well recognized need for improved testing procedures and equipment, human and environmental effect and exposure assessments and full characterization of NM. We also estimate the current level of knowledge to be at an early state of development, and further empirical research will most likely reduce most knowledge gaps. According to this analysis, research should be prioritized towards the assessment and development of test procedures and equipment and full characterization of NM in order to most effectively reduce uncertainties in the short term.

Redefining risk research priorities for nanomaterials

Chemical-based risk assessment underpins the current approach to responsible development of nanomaterials (NM). It is now recognised, however, that this process may take decades, leaving decision makers with little support in the near term. Despite this, current and near future research efforts are largely directed at establishing (eco)toxicological and exposure data for NM, and comparatively little research has been undertaken on tools or approaches that may facilitate near-term decisions, some of which we briefly outline in this analysis. We propose a reprioritisation of NM risk research efforts to redress this imbalance, including the development of more adaptive risk governance frameworks, alternative/complementary tools to risk assessment, and health and environment surveillance.

Emerging Technologies for Environmental Remediation: Integrating Data and Judgment.

Emerging technologies present significant challenges to researchers, decision-makers, industry professionals, and other stakeholder groups due to the lack of quantitative risk, benefit, and cost data associated with their use. Multi-criteria decision analysis (MCDA) can support early decisions for emerging technologies when data is too sparse or uncertain for traditional risk assessment. It does this by integrating expert judgment with available quantitative and qualitative inputs across multiple criteria to provide relative technology scores. Here, an MCDA framework provides preliminary insights on the suitability of emerging technologies for environmental remediation by comparing nanotechnology and synthetic biology to conventional remediation methods. Subject matter experts provided judgments regarding the importance of criteria used in the evaluations and scored the technologies with respect to those criteria. The results indicate that synthetic biology may be preferred over nanotechnology and conventional methods for high expected benefits and low deployment costs but that conventional technology may be preferred over emerging technologies for reduced risks and development costs. In the absence of field data regarding the risks, benefits, and costs of emerging technologies, structuring evidence-based expert judgment through a weighted hierarchy of topical questions may be helpful to inform preliminary risk governance and guide emerging technology development and policy.

Strategic Approaches for the Management of Environmental Risk Uncertainties Posed by Nanomaterials

Central to the responsible development of nanotechnologies is an understanding of the risks they pose to the environment. As with any novel material or emerging technology, a scarcity of data introduces potentially high uncertainty in to the characterisation of risk. Early priorities are the identification of key areas of risk uncertainty and the strategic approach for managing and reducing these. This is important as the information subsequently gathered supports decision making and policy development. We identify one important source of uncertainty for the quantification of both hazard and exposure for nanomaterials, the complexity of their behaviour in natural systems. We then outline two approaches for managing this uncertainty, based on experiences with chemicals: one that primarily focuses on hazard and one that initially focuses on exposure. While each approach places emphasis on different information requirements a common feature is the considerable time lag between information gathering and subsequent decision making based on the evidence gathered. Complementary environmental surveillance approaches can act as a safety net, although it is not as yet clear how fit for purpose current monitoring programmes are in this regard.1

Conceptual modeling for identification of worst case conditions in environmental risk assessment of nanomaterials using nZVI and C60 as case studies

Conducting environmental risk assessment of engineered nanomaterials has been an extremely challenging endeavor thus far. Moreover, recent findings from the nano-risk scientific community indicate that it is unlikely that many of these challenges will be easily resolved in the near future, especially given the vast variety and complexity of nanomaterials and their applications. As an approach to help optimize environmental risk assessments of nanomaterials, we apply the Worst-Case Definition (WCD) model to identify best estimates for worst-case conditions of environmental risks of two case studies which use engineered nanoparticles, namely nZVI in soil and groundwater remediation and C(60) in an engine oil lubricant. Results generated from this analysis may ultimately help prioritize research areas for environmental risk assessments of nZVI and C(60) in these applications as well as demonstrate the use of worst-case conditions to optimize future research efforts for other nanomaterials. Through the application of the WCD model, we find that the most probable worst-case conditions for both case studies include i) active uptake mechanisms, ii) accumulation in organisms, iii) ecotoxicological response mechanisms such as reactive oxygen species (ROS) production and cell membrane damage or disruption, iv) surface properties of nZVI and C(60), and v) acute exposure tolerance of organisms. Additional estimates of worst-case conditions for C(60) also include the physical location of C(60) in the environment from surface run-off, cellular exposure routes for heterotrophic organisms, and the presence of light to amplify adverse effects. Based on results of this analysis, we recommend the prioritization of research for the selected applications within the following areas: organism active uptake ability of nZVI and C(60) and ecotoxicological response end-points and response mechanisms including ROS production and cell membrane damage, full nanomaterial characterization taking into account detailed information on nanomaterial surface properties, and investigations of dose-response relationships for a variety of organisms.

Benefit-risk trade-offs in retrospect: how major stakeholders perceive the decision-making process in the Barents Sea oil field development

This study provides an analysis of risk-benefit communication and participation of the siting process for the Norwegian Goliat oil field development, within the context of a revised model of the International Risk Governance Council’s framework. The main objective of the study is a retrospective review of the decision-making process seen through the lenses of the major stakeholders involved in this process. The research design used qualitative methods of empirical research including stakeholder interviews during a five-day period in 2011 in Northern Norway. Results showed that the siting process of Goliat was dominated primarily by the issue of benefit sharing. In view of potential risks to such oil development, local stakeholders felt entitled to some compensation in terms of shared benefits. However, over the course of time the high hopes that these benefits would materialize and provide additional benefits to the communities which would then be fairly distributed among the beneficiaries have been disappointed. We review the reasons behind these results as well as formulate recommendations regarding potential improvements to the risk-benefit communication process in addition to future siting processes.