1Department of Genetics, Microbiology and Toxicology (GMT), Arrhenius Laboratories of Natural Sciences, Stockholm University, S-106 91 Stockholm, Sweden
2Department of Biosciences and Nutrition, Novum, Karolinska Institute, S-141 57 Huddinge, Sweden
3The Institute for Environmental Medicine (IMM), Karolinska Institute, S-171 77 Stockholm, Sweden
4Department of Environmental Chemistry, Arrhenius Laboratories of Natural Sciences, Stockholm University, S-106 91 Stockholm, Sweden
5Biochemical Institute for Environmental Carcinogens, Lurup 4, D-22927 Grosshansdorf, Germany