Review

The potential risks of nanomaterials: a review carried out for ECETOC

Paul JA Borm¹ , David Robbins² , Stephan Haubold³ , Thomas Kuhlbusch⁴ , Heinz Fissan⁴ , Ken Donaldson⁵ , Roel Schins⁶ , Vicki Stone⁷ , Wolfgang Kreyling⁸ , Jurgen Lademann⁹ , Jean Krutmann⁶ , David Warheit¹⁰ and Eva Oberdorster¹¹

¹  Centre of Expertise in Life Sciences, Zuyd University, Heerlen, The Netherlands

²  Cenamps, Newcastle upon Tyne, UK

³  Nanogate Coating Systems, Saarbrücken, Germany

⁴  IUTA, Duisburg, Germany

⁵  ELEGI, University of Edinburgh, Edinburgh, Scotland, UK

⁶  IUF at the University of Düsseldorf, Düsseldorf, Germany

⁷  Dept of Biological Sciences, Napier University, Edinburgh, Scotland, UK

⁸  GSF-Research Centre for Environment & Health, Institute of Inhalation Biology, Neuherberg, Germany

⁹  Dermatology Clinic, Charite, Berlin, Germany

¹⁰  Haskell Labs, Dupont de Nemours, Wilmington, USA

¹¹  Department of Biology, Southern Methodist University, Dallas, USA

author email corresponding author email

Particle and Fibre Toxicology 2006, 3:11doi:10.1186/1743-8977-3-11

Published:	14 August 2006

Abstract

During the last few years, research on toxicologically relevant properties of engineered nanoparticles has increased tremendously. A number of international research projects and additional activities are ongoing in the EU and the US, nourishing the expectation that more relevant technical and toxicological data will be published. Their widespread use allows for potential exposure to engineered nanoparticles during the whole lifecycle of a variety of products. When looking at possible exposure routes for manufactured Nanoparticles, inhalation, dermal and oral exposure are the most obvious, depending on the type of product in which Nanoparticles are used. This review shows that (1) Nanoparticles can deposit in the respiratory tract after inhalation. For a number of nanoparticles, oxidative stress-related inflammatory reactions have been observed. Tumour-related effects have only been observed in rats, and might be related to overload conditions. There are also a few reports that indicate uptake of nanoparticles in the brain via the olfactory epithelium. Nanoparticle translocation into the systemic circulation may occur after inhalation but conflicting evidence is present on the extent of translocation. These findings urge the need for additional studies to further elucidate these findings and to characterize the physiological impact. (2) There is currently little evidence from skin penetration studies that dermal applications of metal oxide nanoparticles used in sunscreens lead to systemic exposure. However, the question has been raised whether the usual testing with healthy, intact skin will be sufficient. (3) Uptake of nanoparticles in the gastrointestinal tract after oral uptake is a known phenomenon, of which use is intentionally made in the design of food and pharmacological components. Finally, this review indicates that only few specific nanoparticles have been investigated in a limited number of test systems and extrapolation of this data to other materials is not possible. Air pollution studies have generated indirect evidence for the role of combustion derived nanoparticles (CDNP) in driving adverse health effects in susceptible groups. Experimental studies with some bulk nanoparticles (carbon black, titanium dioxide, iron oxides) that have been used for decades suggest various adverse effects. However, engineered nanomaterials with new chemical and physical properties are being produced constantly and the toxicity of these is unknown. Therefore, despite the existing database on nanoparticles, no blanket statements about human toxicity can be given at this time. In addition, limited ecotoxicological data for nanomaterials precludes a systematic assessment of the impact of Nanoparticles on ecosystems.