Background

The concepts and frameworks for assessing and managing human health risks have shifted radically within the last years. On the one hand, precaution became the dominant principle in dealing with uncertain and ambiguous risks (EC 2000a), while on the other hand, participatory procedures are emphasized that have the aim to bring scientists and the public closer together, which also extends to the field of biomedicine (Niewöhner et al. 2004; Wiedemann et al. 2004). Other current issues concerning the improvement of risk assessment as well as the evaluation and management of risks encompass the need for harmonization of risk assessment procedures (EC 2000b), the need for transparency of risk characterisation (EPA 2000a), and the necessity of an integrative approach to risk assessment (EPA 2000b).

However, new challenges for risk assessors are currently becoming apparent, due to the fast and fundamental developments in biomedicine. Medical genetics and stem cell biology are shaking up the theory and practice of medicine as well as of health risk assessment (Aardema & MacGregor 2002). The focus of modern medicine is shifting towards the genetic dispositions of diseases, which can be described on an increasingly individual level. New diagnostic and therapeutic methods (e.g. automatic DNA-sequencing, the use of gene chips or stem cells) allow for individual prognoses in terms of probabilities of dispositions. (1) Even individual prevention and individual therapies can be tailor-made.

This development provides new opportunities for better risk assessment that are usually summarized under the label of “toxicogenomics” (Simmons & Portier 2002). “Toxicogenomics” is explained by the US National Center for Toxicogenomics as “The collection, interpretation, and storage of information about gene and protein activity in order to identify toxic influences by the environment, and to help treat people at the greatest risk of diseases caused by environmental pollutants or toxicants.”

Toxicogenomics is expected to change radically the basis on which human health risks will be identified, and assessed, and mitigated. It promises:

• A better indication of physiological and structural changes of the organism through molecular biomarkers (2)
• a better explanation of the linkages between exposure to stressors, mechanism of action, biological effects and adverse effects,
• enhancement of the understanding of genetic variations of risk susceptibility, better knowledge about risk factors and the improvement of the predictive power of risk assessments.

These promises, if realized, will result in better exposure assessments, in reduction of uncertainties for risk assessments, and in the development of individualized human health risk assessments, while taking into account genetic diversity, individual lifestyle, and environmental conditions (see also Goldstein 2005). WHO has recognized the relevance of this topic by organizing an international workshop "Application of Proteomics and Transcriptomics in EMF Research” that will be held in October 2005. Its aim is to review the application of these relatively new high-throughput screening techniques for the research of biological effects of low- and high-frequency electromagnetic fields (3).

No doubt, toxicogenomics will also challenge current practices of risk characterization, risk communication and risk management.

• (1) These developments are assessed very differently with respect to the predicted timeframes of realization as well as to their impacts, as a recent Delphi study about the future of stem cell research has shown (Wiedemann et al. 2004).
• (2) The term "biomarker" is used in a broad sense to include almost any measurement reflecting an interaction between a biological system and an environmental agent, which may be chemical, physical or biological (WHO1993).
• (3) http://www.who.int/peh-emf/meetings/proteomics_helsinki05/en/print.html