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. We measured the main indoor and outdoor pollutants at the schools.


RESULTS
Overall, the prevalence of asthma and of allergic diseases exhibited an increasing trend in the time interval between the two studies, significant only for dry cough and pollen allergy. The level of air pollutants decreased significantly indoors. In spite of this, we found a correlation and a dose-effect relationship between the level of PM2.5 and the prevalence of asthma. A family history of asthma and allergies, the insalubrity of the place of residence, and a non-Mediterranean diet were also associated with the risk of these diseases.


CONCLUSION
In the time interval between the two studies, which were 18 years apart, despite a reduction in the level of air pollutants in classrooms, asthma was still related to PM2.5. Other potentially causative or contributing environmental factors were also related to asthma and allergies.
['Sasso|Fabien|F|', 'Izard|Mathieu|M|', 'Beneteau|Thomas|T|', 'Rakotozandry|Thierry|T|', 'Ramadour|Myriam|M|', 'Annesi-Maesano|Isabella|I|', 'Robin|Dominique|D|', 'Charpin|Denis|D|']
D000393:Air Pollutants D000397:Air Pollution D016902:Air Pollution, Indoor D001249:Asthma D002648:Child D003371:Cough D005260:Female D005602:France D006801:Humans D006967:Hypersensitivity D008297:Male D015995:Prevalence D006255:Rhinitis, Allergic, Seasonal D012307:Risk Factors D012574:Schools D011795:Surveys and Questionnaires D013997:Time Factors
Asthma Air pollution Epidemiology Children Prevalence Allergy