Nanotechnology regulation: a study in claims making

Prospects and hazards of silica nanoparticles: Biological impacts and implicated mechanisms

With the thrive of nanotechnology, silica nanoparticles (SiNPs) have been extensively adopted in the agriculture, food, cosmetic, and even biomedical industries. Due to the mass production and use, SiNPs inevitably entered the environment, resulting in ecological toxicity and even posing a threat to human health. Although considerable investigations have been conducted to assess the toxicity of SiNPs, the correlation between SiNPs exposure and consequent health risks remains ambiguous. Since the biological impacts of SiNPs can differ from their design and application, the toxicity assessment for SiNPs may be extremely difficult. This review discussed the application of SiNPs in different fields, especially their biomedical use, and documented their potential release pathways into the environment. Meanwhile, the current process of assessing SiNPs-related toxicity on various model organisms and cell lines was also detailed, thus estimating the health threats posed by SiNPs exposure. Finally, the potential toxic mechanisms of SiNPs were also elaborated based on results obtained from both in vivo and in vitro trials. This review generally summarizes the biological effects of SiNPs, which will build up a comprehensive perspective of the application and toxicity of SiNPs.

Regulation of engineered nanomaterials: current challenges, insights and future directions

Substantial production and wide applications of engineered nanomaterials (ENMs) have raised concerns over their potential influences on the environment and humans. However, regulations of products containing ENMs are scarce, even in countries with the greatest volume of ENMs produced, such as the United States and China. After a comprehensive review of life cycles of ENMs, five major challenges to regulators posed by ENMs are proposed in this review: (a) ENMs exhibit variable physicochemical characteristics, which makes them difficult for regulators to establish regulatory definition; (b) Due to diverse sources and transport pathways for ENMs, it is difficult to monitor or predict their fates in the environment; (c) There is a lack of reliable techniques for quantifying exposures to ENMs; (d) Because of diverse intrinsic properties of ENMs and dynamic environmental conditions, it is difficult to predict bioavailability of ENMs on wildlife and the environment; and (e) There are knowledge gaps in toxicity and toxic mechanisms of ENMs from which to predict their hazards. These challenges are all related to issues in conventional assessments of risks that regulators rely on. To address the fast-growing nanotechnology market with limited resources, four ENMs (nanoparticles of Ag, TiO₂, ZnO and Fe₂O₃) have been prioritized for research. Compulsory reporting schemes (registration and labelling) for commercial products containing ENMs should be adopted. Moreover, to accommodate their potential risks in time, an integrative use of quantitative structure-activity relationship and adverse outcome pathway (QSAR-AOP), together with qualitative alternatives to conventional risk assessment are proposed as tools for decision making of regulators.

Has Toxicity Testing Moved into the 21st Century? A Survey and Analysis of Perceptions in the Field of Toxicology

BACKGROUND

Ten years ago, leaders in the field of toxicology called for a transformation of the discipline and a shift from primarily relying on traditional animal testing to incorporating advances in biotechnology and predictive methodologies into alternative testing strategies (ATS). Governmental agencies and academic and industry partners initiated programs to support such a transformation, but a decade later, the outcomes of these efforts are not well understood.

OBJECTIVES

We aimed to assess the use of ATS and the perceived barriers and drivers to their adoption by toxicologists and by others working in, or closely linked with, the field of toxicology.

METHODS

We surveyed 1,381 toxicologists and experts in associated fields regarding the viability and use of ATS and the perceived barriers and drivers of ATS for a range of applications. We performed ranking, hierarchical clustering, and correlation analyses of the survey data.

RESULTS

Many respondents indicated that they were already using ATS, or believed that ATS were already viable approaches, for toxicological assessment of one or more end points in their primary area of interest or concern (26-86%, depending on the specific ATS/application pair). However, the proportions of respondents reporting use of ATS in the previous 12 mo were smaller (4.5-41%). Concern about regulatory acceptance was the most commonly cited factor inhibiting the adoption of ATS, and a variety of technical concerns were also cited as significant barriers to ATS viability. The factors most often cited as playing a significant role (currently or in the future) in driving the adoption of ATS were the need for expedited toxicology information, the need for reduced toxicity testing costs, demand by regulatory agencies, and ethical or moral concerns.

CONCLUSIONS

Our findings indicate that the transformation of the field of toxicology is partly implemented, but significant barriers to acceptance and adoption remain. https://doi.org/10.1289/EHP1435.

Gold Nanoparticles for Diagnostics: Advances towards Points of Care

The remarkable physicochemical properties of gold nanoparticles (AuNPs) have prompted developments in the exploration of biomolecular interactions with AuNP-containing systems, in particular for biomedical applications in diagnostics. These systems show great promise in improving sensitivity, ease of operation and portability. Despite this endeavor, most platforms have yet to reach maturity and make their way into clinics or points of care (POC). Here, we present an overview of emerging and available molecular diagnostics using AuNPs for biomedical sensing that are currently being translated to the clinical setting.

China and the United States--Global partners, competitors and collaborators in nanotechnology development

USA and China are two leading countries engaged in nanotechnology research and development. They compete with each other for fruits in this innovative area in a parallel and compatible manner. Understanding the status and developmental prospects of nanotechnology in USA and China is important for policy-makers to decide nanotechnology priorities and funding, and to explore new ways for global cooperation on key issues. We here present the nanoscience and nanomedicine research and the related productivity measured by publications, and patent applications, governmental funding, policies and regulations, institutional translational research, industrial and enterprise growth in nanotechnology-related fields across China and USA. The comparison reveals some marked asymmetries of nanotechnology development in China and USA, which may be helpful for future directions to strengthen nanotechnology collaboration for both countries, and for the world as a whole.

Are nanosized or dissolved metals more toxic in the environment? A meta-analysis

Recently, much has been written about the extreme urgency of elaborating the regulations for engineered nanomaterials. Such regulations are needed both from lawmakers, to protect people from potentially adverse effects, and from industry representatives, to prove that nanoproducts are produced carefully and with caution to avoid possible lawsuits. However, developing regulations has proven to be a difficult task, and an ambiguous topic where errors can easily occur. In the present study, the authors present a meta-analysis of 3 different nanomaterials (nano-Ag, nano-ZnO, and nano-CuO) in which data from ecotoxicity studies and published half-maximal effective concentration (EC50) values are compared for both the nano form and the corresponding dissolved metal. A ratio equal to 1 means that the particle is as toxic as the dissolved metal ion, whereas a lower ratio signifies that the nano form is less toxic than the dissolved metal based on total metal concentrations. The results show that for 93.8% (Ag), 100% (Cu), and 81% (Zn) of the ratios considered, the nano form is less toxic than the dissolved metal in terms of total metal concentration. Very few of the studies surveyed found a ratio of EC50 values for (dissolved/nano) that was larger than 2 (Ag: 1.1%; Cu: 0%; Zn: 2.8%). Hence, a reduction in existing metal concentration thresholds by a factor of 2 in current freshwater and soil regulations for ecotoxicity may be sufficient to protect organisms and compartments from the nano form of these metals as well.

Scientists versus regulators: precaution, novelty & regulatory oversight as predictors of perceived risks of engineered nanomaterials

Engineered nanoscale materials (ENMs) present a difficult challenge for risk assessors and regulators. Continuing uncertainty about the potential risks of ENMs means that expert opinion will play an important role in the design of policies to minimize harmful implications while supporting innovation. This research aims to shed light on the views of ‘nano experts’ to understand which nanomaterials or applications are regarded as more risky than others, to characterize the differences in risk perceptions between expert groups, and to evaluate the factors that drive these perceptions. Our analysis draws from a web-survey (N = 404) of three groups of US and Canadian experts: nano-scientists and engineers, nano-environmental health and safety scientists, and regulatory scientists and decision-makers. Significant differences in risk perceptions were found across expert groups; differences found to be driven by underlying attitudes and perceptions characteristic of each group. Nano-scientists and engineers at the upstream end of the nanomaterial life cycle perceived the lowest levels of risk, while those who are responsible for assessing and regulating risks at the downstream end perceived the greatest risk. Perceived novelty of nanomaterial risks, differing preferences for regulation (i.e. the use of precaution versus voluntary or market-based approaches), and perceptions of the risk of technologies in general predicted variation in experts' judgments of nanotechnology risks. Our findings underscore the importance of involving a diverse selection of experts, particularly those with expertise at different stages along the nanomaterial lifecycle, during policy development.

Implementation of a multidisciplinary approach to solve complex nano EHS problems by the UC Center for the Environmental Implications of Nanotechnology

UC CEIN was established with funding from the US National Science Foundation and the US Environmental Protection Agency in 2008 with the mission to study the impact of nanotechnology on the environment, including the identification of hazard and exposure scenarios that take into consideration the unique physicochemical properties of engineered nanomaterials (ENMs). Since its inception, the Center has made great progress in assembling a multidisciplinary team to develop the scientific underpinnings, research, knowledge acquisition, education and outreach that is required for assessing the safe implementation of nanotechnology in the environment. In this essay, the development of the infrastructure, protocols, and decision-making tools that are required to effectively integrate complementary scientific disciplines allowing knowledge gathering in a complex study area that goes beyond the traditional safety and risk assessment protocols of the 20th century is outlined. UC CEIN's streamlined approach, premised on predictive hazard and exposure assessment methods, high-throughput discovery platforms and environmental decision-making tools that consider a wide range of nano/bio interfaces in terrestrial and aquatic ecosystems, demonstrates the implementation of a 21st-century approach to the safe implementation of nanotechnology in the environment.

Minimum physicochemical characterisation requirements for nanomaterial regulation

Appropriate characterisation of manufactured nanomaterials (NMs) is vital for many aspects of their synthesis, product formulation, toxicological testing and regulation. As the range and quantity of NMs in production has expanded, the interest in their potential environmental and toxicological consequences has grown. With this growth, there is increased need for clarity and rigour in characterising appropriate physicochemical parameters. Which physicochemical parameters should be characterised and under what conditions remains a topic of debate, along with the most appropriate techniques and methodologies to best describe any one characteristic. This review assesses the characterisation requirements of current and future regulatory frameworks for NMs, with specific focus on the incoming REACH framework of the EU. For regulatory compliance, characterisation requirements will be necessarily prescriptive. The minimum physicochemical parameters required to adequately describe NMs for regulatory purposes are proposed, along with a discussion of the most appropriate mechanisms to obtain those data in terms of the overarching delivery mechanism. Guiding principles for particle characterisation during the hazard testing required to comply with regulations are examined.

The hierarchy of environmental health and safety practices in the U.S. nanotechnology workplace

Manufacturing of nanoscale materials (nanomaterials) is a major outcome of nanotechnology. However, the potential adverse human health effects of manufactured nanomaterial exposure are not yet fully understood, and exposures in humans are mostly uncharacterized. Appropriate exposure control strategies to protect workers are still being developed and evaluated, and regulatory approaches rely largely on industry self-regulation and self-reporting. In this context of soft regulation, the authors sought to: 1) assess current company-reported environmental health and safety practices in the United States throughout the product life cycle, 2) consider their implications for the manufactured nanomaterial workforce, and 3) identify the needs of manufactured nanomaterial companies in developing nano-protective environmental health and safety practices. Analysis was based on the responses of 45 U.S.-based company participants in a 2009-2010 international survey of private companies that use and/or produce nanomaterials. Companies reported practices that span all aspects of the current government-recommended hierarchical approach to manufactured nanomaterials' exposure controls. However, practices that were tailored to current manufactured nanomaterials' hazard and exposure knowledge, whether within or outside the hierarchical approach, were reported less frequently than general chemical hygiene practices. Product stewardship and waste management practices-the influences of which are substantially downstream-were reported less frequently than most other environmental health and safety practices. Larger companies had more workers handling nanomaterials, but smaller companies had proportionally more employees handling nanomaterials and more frequently identified impediments to implementing nano-protective practices. Company-reported environmental health and safety practices suggest more attention to environmental health and safety is necessary, especially with regard to practices that can cause external effects. Given reported impediments, smaller companies may especially benefit from more attention. However, the manufactured nanomaterial workforce within smaller companies is particularly difficult to identify and hence locate, posing challenges to developing and enforcing appropriate workplace environmental health and safety. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a file containing Survey of Current Health and Safety Practices in the Nanomaterial Industry and a file containing figures.].

Magnetophoresis of nanoparticles

Iron oxide cores of 35 nm are coated with gold nanoparticles so that individual particle motion can be tracked in real time through the plasmonic response using dark field optical microscopy. Although Brownian and viscous drag forces are pronounced for nanoparticles, we show that magnetic manipulation is possible using large magnetic field gradients. The trajectories are analyzed to separate contributions from the different types of forces. With field gradients up to 3000 T/m, forces as small as 1.5 fN are detected.