The ECETOC-EEMS symposium on the “Toxicology/genotoxicity of manufactured nanoparticles” was held on Tuesday 11 September 2007 in Basel during the annual general meeting of EEMS, the European Environmental Mutagen Society. The aim was to present new data from on-going industry/academic projects on genotoxicity and draw attention to related relevant aspects such as characterisation, exposure, transportation, mode of action and immuno-translocation. The Symposium programme (attached) included presentations on these aspects plus results of genotoxicity testing of typical nanoparticles (TiO2 and ZnO) and newly engineered nanofibres (nanotubes). At the symposium, CEFIC-LRI and ECETOC were mentioned as sponsor and organiser, respectively, and described in the conference abstract booklet. All practical (e.g. speakers’ hotel/travel) and local (conference) arrangements were made by the EEMS 2007 organisers. The organising ECETOC Task Force met in December 2006 to draw up a programme with topics and speakers. The ECETOC Scientific Committee/EEMS Scientific Programme Committee adopted it in January/February 2007. The Symposium was well attended by over 200 (out of a total of 350) registered conference participants, mostly from academia, government, contract research organisations and pharmaceutical industry. The audience, including many key scientists, showed a high interest in this new topic of nano(geno)toxicology. The full programme involved short speaker presentations, leaving little time for questions from the audience. But there were lively discussions during the breaks and beyond (e.g. poster session). Of the organising ECETOC Task Force members (below), Dr Krueger served as co-chairman, Dr van Ravenzwaay presented first results from ongoing inhalation studies, and Dr Nohynek spoke on skin applications. In his conclusions, Dr N. Carmichael highlighted stability of the test system and specific dosimetry as major problems in nanoparticle investigations. Earlier, studies often lacked sufficient characterisation of the test material or lacked appropriate control groups, i.e. in the absence of micro-particle treated groups, it is impossible to decide whether nanoparticle-mediated adverse effects are intrinsic to the test material or specific for particle size. Even in present studies, a change of conditions might alter the results and influence the conclusions, especially in in vitro models. Material reaching the tissue might have different characteristics, e.g. in case of intratracheal instillation. So far, there were few reports of direct genotoxic effects of nanoparticles. Indirect genotoxicity mediated by toxicity might allow for the derivation of thresholds. In all, to be useful for risk assessment, the model system had to be well characterised and representative of the situation.
A set of 9 to 10 papers based on the symposium presentations will be published as a special issue of Toxicology Letters in 2008 (Elsevier Science; Guest editors: Drs H. Norppa and H. Greim; Managing editor Dr W. Dekant). All but one speaker have committed to writing a manuscript. There will also be an introductory editorial and the Guest Editors may wish to write a conclusions paper. The issue will count as ECETOC Monograph. An Editorial Board meeting is planned for November 2007.
The Basel symposium has been the sixth of a series of symposia/workshops on a variety of topics organised in collaboration with EEMS since 1998, published in the open literature and counted as ECETOC Monographs (list attached). CEFIC-LRI has been sponsor since 2004. To capture emerging nano(geno)toxicity data, there might be scope for another joint ECETOC-EEMS symposium at the global International Congress of Environmental Mutagen Societies in 2009. That symposium might also review the adequacy of existing test protocols.