Henning Wigger

Influences of use activities and waste management on environmental releases of engineered nanomaterials.

Engineered nanomaterials (ENM) offer enhanced or new functionalities and properties that are used in various products. This also entails potential environmental risks in terms of hazard and exposure. However, hazard and exposure assessment for ENM still suffer from insufficient knowledge particularly for product-related releases and environmental fate and behavior. This study therefore analyzes the multiple impacts of the product use, the properties of the matrix material, and the related waste management system (WMS) on the predicted environmental concentration (PEC) by applying nine prospective life cycle release scenarios based on reasonable assumptions. The products studied here are clothing textiles treated with silver nanoparticles (AgNPs), since they constitute a controversial application. Surprisingly, the results show counter-intuitive increases by a factor of 2.6 in PEC values for the air compartment in minimal AgNP release scenarios. Also, air releases can shift from washing to wearing activity; their associated release points may shift accordingly, potentially altering release hot spots. Additionally, at end-of-life, the fraction of AgNP-residues contained on exported textiles can be increased by 350% when assuming short product lifespans and globalized WMS. It becomes evident that certain combinations of use activities, matrix material characteristics, and WMS can influence the regional PEC by several orders of magnitude. Thus, in the light of the findings and expected ENM market potential, future assessments should consider these aspects to derive precautionary design alternatives and to enable prospective global and regional risk assessments.

Risks, Release and Concentrations of Engineered Nanomaterial in the Environment

For frequently used engineered nanomaterials (ENMs) CeO2-, SiO2-, and Ag, past, current, and future use and environmental release are investigated. Considering an extended period (1950 to 2050), we assess ENMs released through commercial activity as well as found in natural and technical settings. Temporal dynamics, including shifts in release due to ENM product application, stock (delayed use), and subsequent end-of-life product treatment were taken into account. We distinguish predicted concentrations originating in ENM use phase and those originating from end-of-life release. Furthermore, we compare Ag- and CeO2-ENM predictions with existing measurements. The correlations and limitations of the model, and the analytic validity of our approach are discussed in the context of massive use of assumptive model data and high uncertainty on the colloidal material captured by the measurements. Predictions for freshwater CeO2-ENMs range from 1 pg/l (2017) to a few hundred ng/l (2050). Relative to CeO2, the SiO2-ENMs estimates are approximately 1,000 times higher, and those for Ag-ENMs 10 times lower. For most environmental compartments, ENM pose relatively low risk; however, organisms residing near ENM ‘point sources’ (e.g., production plant outfalls and waste treatment plants), which are not considered in the present work, may be at increased risk.

Broadening our view on nanomaterials: highlighting potentials to contribute to a sustainable materials management in preliminary assessments

Apart from completely novel functionalities, the utilization of nanomaterials (NMs) holds great promise for increasing the performance and efficiency of products and processes. In doing so, they are also expected to be more sustainable in that they may allow for products and processes that can provide better services using less material and energy. However, whether or not NMs do in fact contribute sustainable development still remains a matter of debate. While a relatively high number of risk assessment studies have revealed some of the toxicological and ecotoxicological repercussions of NMs, other sustainability related issues have so far received comparatively little attention. One of these issues refers to the sustainability implications of material use, such as environmental impacts of materials supply, resource depletion, or material criticality. Here, we argue that an adequate assessment of NM-based innovations calls for an inclusion not only of human health and environmental risks but also of aspects related to sustainable materials management. Recognizing the inherent complexity of sustainability issues as well as the difficulties of meeting data needs in early innovation stages, we propose a prospective and preliminary framework to assess the potential benefits and risks of NM-based innovations. We demonstrate the frameworks practicability and usefulness in decision-making contexts by applying it to four in-depth case studies of specific NM-based innovations. Also, we point to some methodological issues that may need consideration in the further improvement of the framework.

Characterizing Synthetic Biology Through Its Novel and Enhanced Functionalities

What distinguishes synthetic biology from earlier approaches in biology and biotechnology? What are future applications that may possibly be realized through synthetic biology? What can be expected from synthetic biology with respect to the benefits it may provide as well as the risks it may pose? This chapter puts forward the idea that these questions, among others that regard the promises and threats of this new and emerging field of science and technology, can be explored by applying the concept of functionality to synthetic-biological structures and systems. Functionality, in this respect, is defined as a certain physicochemical or biological effect that can be brought about by a (synthetic-) biological object. This effect, in turn, has repercussions on the wider systems context the respective object appears in. Looking at the various hierarchical levels of biological life, functionalities that have already been realized through synthetic-biological approaches, as well as those that may be realized through future research and development, are systematically analyzed. Based on this analysis, applications that make use of these functionalities thus far, or may do so in the future, are presented. Furthermore, it is investigated how the functionalities may change the hazardous properties or exposure behavior of the respective structures or systems and thus potentially increase the risk associated with them.

Risk assessment of technological innovations

This chapter will introduce relevant terms laying the foundation for the subsequent chapters of this thesis. At first, technological innovation will be defined and described and the relation to the precautionary principle and TA will be shown. Second, technology characterization is shown in the context of TA to systematically analyze technologies in early innovation stages.

Current and future product applications of iron oxide and silver nanoparticles

The early identification of new technologies and their potential applications constitutes challenges for research, entrepreneurs, and policy stakeholders. This is because of the fact that knowledge on research and development activities is generally available in decentralized form and is often restricted due to confidential issues (Watts and Porter 1997). Thus, plenty of methods exist that aim to provide information for technological forecasting and potential technology trends to assist decision-makers in industrial, regulatory, and subsidies political settings (Watts and Porter 1997).

Background and motivation

Nanotechnologies are promising for various product applications that are accompanied with a significant market potential (Roco 2011). Innovations based on nanomaterials address global challenges like energy, health care, clean water, and climate change (Palmberg et al. 2009) promising to satisfy the economical, social and environmental needs of the society. Consequently, nanotechnologies are often declared as the key technology of the 21st century combining several research disciplines including physics, chemistry, biology and biochemistry.

Case Study: Magnetic resonance imaging based on iron oxide nanoparticles

MRI belongs to the field of biomedical imaging and is one of the most advanced applications in drug delivery and theranostics in which nanomaterials might play a major role in the near future (Wigger et al. 2015b). The MRI principle has been extensively described in literature and only an overview will be given here (cf. Laurent et al. 2008; Na et al. 2009). The fact that each atom has its own atomic spin can be used to visualize soft tissues and organs of the human body.

Conclusion and outlook for future research

In the following, the outcomes of this thesis will be briefly summarized with consideration of the research objectives defined in subsection 1.2. Subsequently, limitations will be discussed and an outlook for future researches will be given.

Approaches for release and product life cycle modeling

From a historical perspective release and emission estimations mainly focused on the release of chemicals or on emissions from technical processes (KEMI 2004; Fissan et al. 2013), which is why no method is directly available for NOAA release estimation (see chapter 2). Moreover, it has also become apparent that the life cycle perspective is a crucial aspect for releases of NOAAs during the product lifespan (Som et al. 2010a). The life cycle stages characterize different types of situational contexts that influence the NOAAs or nano-enhanced products (Mitrano et al. 2015).