18-year evolution of asthma and allergic diseases in French urban schoolchildren in relation to indoor air pollutant levels.

Background: An initial epidemiological study carried out 18 years ago in Marseilles indicated that the air quality in schools was poor and that there was an association between the level of fine particulates and the occurrence of asthma in children. The aim of the present study was to evaluate the change in the prevalence of childhood asthma and allergic diseases and their link with the levels of air pollutants and other factors of potential risk.

Methods: In 2016, using a questionnaire identical to the one used for the 1st survey in 1998-1999, we collected information regarding the symptoms, the diagnosis, and the potential confounding factors.