1. Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
2. Belgian Interregional Environment Agency, Brussels, Belgium
3. Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
4. Department of Obstetrics, East-Limburg Hospital, Genk, Belgium
5. Department of Public Health, Occupational and Environmental Medicine, Leuven University (KULeuven), Leuven, Belgium