1 Department of Pediatrics, Örebro University Hospital, Örebro, Sweden. Electronic address: nikimitselou@gmail.com.
2 Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Sachs' Children and Youth Hospital, Södersjukhuset, Stockholm, Sweden.
3 Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, United Kingdom; Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY.