1. Epidemiology and Biostatistics Section, Scientific Directorate, G Gaslini Children's Hospital, Genoa;
2. Unit of Public Health, Local Health Unit 5 (ASL 5), La Spezia;
3. Environmental Toxicology Section, Environmental Protection Agency of the Ligurian Region (ARPAL), La Spezia;
4. Department of Epidemiology and Health Service Research, National Research Council (CNR), Pisa;
5. Tumor Registry Section, National Cancer Research Institute, Genoa;
6. Department of Oncology, Biology and Genetics, University of Genoa;
7. Department of Environmental Epidemiology, National Cancer Research Institute, Genoa, Italy