1. Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstrasse 30, 48149 Münster, Germany, Department of Medicine I, Marienhospital Herne, Ruhr-University of Bochum, Hölkeskampring 40, 44625 Herne, Germany, Environmental Specimen Bank for Human Tissues, Domagkstrasse 11, 48149 Münster, Germany, and Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Strasse 33, 48149 Münster, Germany