Guest Editorial

Last year (2008) in September we organized the 2nd International Conference on Nanotoxicology in Zurich, Switzerland (NANOTOX 2008). This event was the corollary of the increasing activities and publications in this field. It was necessary as there should be at least one meeting every second year, to align and compare the thoughts and the results which are produced by the huge number of people working in the laboratories on this topic. This is essential as a point of criticism for the ‘nanotoxicology community’ is the lack of standardization of methods, and the diverging results that have been published so far. Thus, it is very important to have the key players in the field all together at one place discussing the newest experimental data. This is the aim of this series of events which will, over time, increase in terms of the number of participants. We began in 2006 with around 100 scientists at the meeting in Miami and grew to about 260 in 2008 in Zurich. Independent from government or industry we focused on the urgent questions regarding the biological and environmental problems arising with the increasing use of nanomaterials throughout our daily life. Having this in mind, we included within the sessions of our meeting the most important topics such as:

• Characterisation and analytics of nanomaterials;

• Exposure scenarios and their evaluation;

• Biokinetics of nanomaterials in living organisms;

• General biological effects in various systems or cell models;

• Aerosols of nanoparticles and their effects on the lung;

• Direct effects of nanomaterials on the immune system;

• Genotoxicity of nanomaterials;

• Ecotoxicology and risk assessment.

As one can imagine, these points cover almost the entire field of nanotoxicology; the meeting was therefore organized to gain an overview of the newest and most outstanding results, which were presented by the most prominent scientists in their fields. The three institutions involved in the organization of this conference, the University of Berne, the ETH Zurich and the Federal Institute of Materials Testing and Research (Empa) in St Gallen, are by themselves working in different topics of nanotoxicology, reflecting materials synthesis and analytics, biological effects in the lung as well as in different tissues and cellular systems. This highlights directly another aspect of nanotoxicology which makes it very special in comparison to other fields of toxicology – the interdisciplinarity of the research. Without chemical and physical analysis of the materials and their properties, research on their biological effects is relatively worthless, as it would be impossible to conclude anything about the relationship between material properties and their mode of action in biological systems. Without knowledge of exposure in the workplace or during the use of the nanomaterials, risk assessment cannot be conducted, and without the measurement of their distribution in the environment and the determination of the environmental effects, no calculation of the possible consequences of their use could be carried out.

Therefore, it is necessary that the experts in these different fields meet each other regularly to sum up the present knowledge and come to updated conclusions leading to a sustainable development of nanotechnologies and the use of nanomaterials. This has to be done in a very responsible and self-critical way as many published data so far are not useful because of missing information on the physico-chemical properties, the huge differences in concentrations applied, the large variety of biological systems tested and the use of non-evaluated methods which, in many cases, are directly affected by the investigated materials itself. These difficulties should be overcome very rapidly and this could only be achieved when the key players in the field come together setting the benchmarks for the investigation of nanomaterials and publish these as instructions or rules that have to be optimized in an iterative process over time.

Connected to this, it is a pleasure to present 4 lectures of the Zurich-meeting as papers in this issue of Nanotoxicology and I hope that this will encourage all scientists working in this field to participate in the following meetings, of which the next will be held in Edinburgh from 2–4 June 2010.