11. Genetic factors in asthma and COPD 139 H. Marike Boezen, Kim de Jong and Judith M. Vonk 12. Early life events including transgenerational epigenetic effects 152 on respiratory outcomes Thomas Rossor and Anne Greenough 13. Active and passive tobacco smoking 165 Laura Carrozzi, Sandra Baldacci, Marzia Simoni and Stefano Nardini 14. Outdoor air pollution 179 Annunziata Faustini, Marie-Eve Héroux and Francesco Forastiere 15. Indoor air pollution 198 Marzia Simoni, Isabella Annesi-Maesano and Giovanni Viegi 16. Work-related respiratory diseases in the European Union 211 Dick Heederik and Torben Sigsgaard 17. Diet 224 Foteini Malli, Konstantinos I. Gourgoulianis and Zoe Daniil 18. Poverty and health disparities 241 Valeska Padovese, Raffaele Di Palma and Concetta Mirisola 19. Study design: features of non-experimental studies 249 Vittoria Colamesta and Riccardo Pistelli 20. Questionnaires and lung function 257 Francesco Pistelli and Sara Maio 21. Inflammation and allergy related to bronchial hyperresponsiveness 273 Christer Janson and Andrei Malinovschi