1. Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden, Departments of Environmental Chemistry, Botany, and Applied Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden, Contaminant Research Group, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden, and Hyogo Prefectural Institute of Public Health and Environmental Science, 654-0037 Kobe, Japan