1. Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden;
2. Department of Occupational and Environmental Medicine, Umeå University, Umeå, Sweden;
3. Man-Technology-Environment Research Center (MTM), Department of Science, Örebro University, Örebro, Sweden;
4. Department of Chemical and Biological Work Environment, National Institute of Occupational Health, Oslo, Norway