Indoor Environmental Factors and Chronic Diseases in Swedish Pre-School Children

......................................................................................................5 SAMMANFATTNING......................................................................................7 LIST OF PAPERS ...........................................................................................11 ABBREVIATIONS .........................................................................................12 INTRODUCTION..........................................................................................13 Chronic disease of public health concern ............................................................................................ 14 Asthma, rhinitis and eczema ...................................................................................................................... 14 Autism spectrum disorders.......................................................................................................................... 15 Comorbidity ............................................................................................................................................ 15 Burden of disease ...................................................................................................................................... 16 World wide time trends ......................................................................................................................... 17 Increase in allergic diseases during the last decades............................................................................................ 17 Has autism spectrum disorders increased? ...................................................................................................... 22 Interaction between exposures and genetic predisposition................................................................ 22 Genetic predisposition ................................................................................................................................ 22 Environmental exposures ........................................................................................................................... 24 Psychological and social factors..................................................................................................................... 26 Indoor environmental risk factors ........................................................................................................ 27 Moisture related problems and asthma .......................................................................................................... 27 Chemical exposure and asthma.................................................................................................................... 29 Chemical exposure and autism spectrum disorders............................................................................................ 31 Methodological problems in epidemiology ......................................................................................... 32 AIMS AND OBJECTIVES ..............................................................................34 MATERIALS AND METHODS......................................................................35 The DBH-study ..................................................................................................................................... 35 DBH Phase I.......................................................................................................................................... 35 DBH phase II......................................................................................................................................... 36 DBH phase III ....................................................................................................................................... 36 DBH phase IV ....................................................................................................................................... 36 The study population............................................................................................................................. 37