Acknowledgements
The study was performed within the EU 6th Framework study INTARESE (coordinated by David Briggs) and the strategic research program of the Dutch National Institute for Public Health and the Environment (RIVM). We gratefully acknowledge the contribution of Erkki Kuusisto, Jouni Tuomisto, Kari Pesonen, Rainer Friedrich, Anna Sillero Larena, and Mark Nieuwenhuijsen for their help with the translations and their useful suggestions during the earlier versions of our survey. Alistair Hunt provided insightful and valuable comments and advised in various stages of the project. In addition, we also would like to thank our respondents for their invaluable contribution to this valuation study.