1. Center for Environmental and Health Sciences, Hokkaido University, North 12, West 7, Sapporo 060-0812, Japan
2. Faculty of Health Sciences, Hokkaido University, North 12, West 5, Sapporo 060-0812, Japan
3. Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, Bochum 44789, Germany
4. Toxicological Center, University of Antwerp, Universiteitsplein 1, Wilrijk 2610, Belgium