1. Air Pollution Exposure Laboratory, Division of Respiratory Medicine, Department of Medicine, The University of British Columbia, Vancouver, British Columbia V5Z 1M9, Canada
2. Division of Physiological Chemistry 2, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm SE-171 65, Sweden
3. Unit of Lung and Allergy Research, Institute of Environmental Medicine, Karolinska Institutet, Stockholm SE-171 77, Sweden
4. Occupational and Environmental Health Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario M5T 1P8, Canada
5. Department of Respiratory Medicine and Allergy, Karolinska University Hospital, Stockholm SE-171 76, Sweden
6. Gunma University Initiative for Advanced Research (GIAR), Gunma University, Maebashi, Gunma 371-8511, Japan