Modifications of health behaviour in response to air pollution notifications in Copenhagen.

Ambient air quality is a major issue today in large cities all over the world. On the theoretical background of the health belief model and the health locus of control model, we studied the knowledge and beliefs about air pollution and the modifications of health behaviour brought about by information to the public about projected levels of air pollution, with special emphasis on reduction of outdoor activity and avoidance of car driving. Data were collected with a questionnaire among a sample of residents in the Copenhagen area. The respondents were almost universally knowledgeable about the prime emission source and concerned about the possible health effects of the air pollution in the area. Avoidance of outdoor activity was associated with personal experiences of symptoms ascribed to the air pollution, employment status, and with female sex, but not with knowledge or beliefs about the degree or health implications of the air pollution. The willingness to avoid car driving was positively associated with the belief that one can oneself influence one's health and with female sex. Lung diseased respondents were generally more prone to protect themselves than the healthy, both by avoiding outdoor activity and by being less willing to avoid car driving. The present study was conducted in an only moderately polluted city, and it is not clear whether the findings and conclusions can be generalized to more polluted cities. The study partly supported the underlying theories of the determinants of health behaviour, but also indicated a need for a broader theoretical framework, incorporating aspects of the respondents' life situation and personal experience which would be relevant to the specific type of health behaviour under study.