1. Department of Hygiene, Social and Environmental Medicine, MA 1/33, Ruhr-University Bochum, Universitätsstrasse 150, 44801 Bochum, Germany
2. Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, University Erlangen-Nuremberg, Germany
3. Staatliches Veterinäruntersuchungsamt, Arnsberg, Germany
4. North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection, Recklinghausen, Germany