1. Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan
2. Unit of Integrative Metabolomics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm 171 77, Sweden
3. Department of Respiratory Medicine and Allergy, Karolinska University Hospital, Stockholm 171 77, Sweden
4. Department of Comparative and Experimental Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan
5. Department of Chemistry, Faculty of Life Sciences, Tokyo University of Agriculture, Setagaya, Tokyo 156-8502, Japan