1. Environmental Epidemiology Unit, National Public Health Institute, Kuopio, Finland
2. Environmental and Occupational Health Division, Institute for Risk Assessment Sciences, Utrecht University, the Netherlands
3. Institute of Epidemiology, GSF-National Research Center for Environment and Health, Neuherberg, Germany
4. Center for Environmental Health Research, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
5. Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland
6. University of Kuopio, Kuopio, Finland