1 Institute for Risk Assessment Sciences and Julius Center for Health Sciences and Primary Care UMCU, Utrecht University, PO Box 80178, 3508 TD Utrecht, Netherlands. Electronic address: b.brunekreef@uu.nl.
2 National Centre for Atmospheric Science, School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK; Department of Environmental Sciences/Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah, Saudi Arabia.
3 Swiss Tropical and Public Health Institute Basel, Switzerland and University of Basel, Basel, Switzerland.
4 Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain.
5 Natural Environment Research Council (NERC) Centre for Ecology and Hydrology, Edinburgh Research Station, Bush Estate, Penicuik, EH26 0QB, UK.
6 Institute for Risk Assessment Sciences and Julius Center for Health Sciences and Primary Care UMCU, Utrecht University, PO Box 80178, 3508 TD Utrecht, Netherlands.
7 Department of Public Health, Aarhus University, Aarhus, Denmark.