Critical age windows in the impact of lifetime smoking exposure on respiratory symptoms and disease among ever smokers.

Background: Despite extensive knowledge of smoking effects on respiratory disease, there is no study including all age windows of exposure among ever smokers. The objective of this study was to assess the effects from smoking exposure in utero, early childhood, adolescence and adulthood on respiratory health outcomes in adult male and female ever smokers.

Methods: Respiratory health outcomes were assessed in 10,610 participants of the European Community Respiratory Health Survey (ECRHS) I who reported a history of ever smoking by questionnaire.