Nanomaterials: A Challenge for Toxicological Risk Assessment?

Abstract

Nanotechnology has emerged as one of the central technologies in the twenty-first century. This judgment becomes apparent by considering the increasing numbers of people employed in this area; the numbers of patents, of scientific publications, of products on the market; and the amounts of money invested in R&D. Prospects originating from different fields of nanoapplication seem unlimited. However, nanotechnology certainly will not be able to meet all of the ambitious expectations communicated, yet has high potential to heavily affect our daily life in the years to come. This might occur in particular in the field of consumer products, for example, by introducing nanomaterials in cosmetics, textiles, or food contact materials. Another promising area is the application of nanotechnology in medicine fueling hopes to significantly improve diagnosis and treatment of all kinds of diseases. In addition, novel technologies applying nanomaterials are expected to be instrumental in waste remediation and in the production of efficient energy storage devices and thus may help to overcome world's energy problems or to revolutionize computer and data storage technologies. In this chapter, we will focus on nanomaterials. After a brief historic and general overview, current proposals of how to define nanomaterials will be summarized. Due to general limitations, there is still no single, internationally accepted definition of the term "nanomaterial." After elaborating on the status quo and the scope of nanoanalytics and its shortcomings, the current thinking about possible hazards resulting from nanoparticulate exposures, there will be an emphasis on the requirements to be fulfilled for appropriate health risk assessment and regulation of nanomaterials. With regard to reliable risk assessments, until now there is still the remaining issue to be resolved of whether or not specific challenges and unique features exist on the nanoscale that have to be tackled and distinctively addressed, given that they substantially differ from those encountered with microsized materials or regular chemicals. Based on the current knowledge, we finally provide a proposal on how risk assessment in the nanofield could be achieved and how it might look like in the near future.

Interaction of Nanoparticles with Blood Components and Associated Pathophysiological Effects

“…The studies about the nanomaterials started fifteen years ago, and knowledge regarding their toxic potential is still limited and without appropriate regulatory measures in place [4][5][6]. Toxicologists, epidemiologists, and sociologists have particularly debated the future implications of nanotechnology as well as concerns regarding their toxicity and potential environmental impact.…”

Critical review of methods for risk ranking of food-related hazards, based on risks for human health

“…In general these methods are used to obtain a qualitative indication about the risks associated with hazards. Haase et al (2012), for example, established a decision tree for nanoparticles to determine whether a full risk assessment is required or not. EFSA described guidelines for classifying chemical hazards as negligible, low, medium, and high risks (EFSA, 2012c(EFSA, , 2012d.…”

Health effects of nanomaterials

“…Engineered nanoparticles are synthesized from a diverse range of materials, in various shapes and sizes, and may be functionalized with a wide variety of chemicals. This means that thousands of physicochemical formats could potentially be synthesized and, as a consequence, of nanomaterials classification of nanomaterials for toxicological purposes is complex and still under consideration 1,2 ; the European Committee for Standardization (CEN) 7 have proposed that nanomaterials should be categorized into (i) nano-objects [e.g. nanospheres, plates and rods (including fibres, wires and tubes); these may be hollow, solid and/ or with a range of surface properties], or (ii) nanostructured materials, i.e.…”

“…Particulate matter below 10 and 2.5 μm (PM 10 and PM 2.5 ) aerodynamic diameter contains both natural and anthropogenic particles. The nanosized component of PM contains combustion products, including diesel exhaust particles, which Although the exact definition of a nanomaterial/ nanoparticle is still under debate 1,2 , it is generally accepted that a nanoparticle has at least one dimension less than 100 nm; nanoparticles can therefore be smaller than most cellular organelles and are likely to be perceived by cells as biological entities that require processing. This property is being harnessed for new drug delivery systems and other medical applications.…”