Traffic Related Respiratory Alterations in Schoolchildren in Milan, Italy

MARCO SALA (1), Francesco Cetta (2,3), Sabrina Argirò (1), Patrizia Ballista (1), Luca Ferrero (4), Rosalia Zangari (2), Valentina Guercio (2), Ezio Bolzacchini (4), Marcello Giovannini (1)

(1) University of Milan, Italy (2) University of Siena, Italy (3) Geriatric Institute “Pio Albergo Trivulzio” (PAT), Milan, Italy (4) University of Milano-Bicocca, Italy

     Abstract Number: 2486
     Last modified: February 8, 2010

Abstract
Recent studies outlined the possibility of important adverse effects on children health due to air pollutants. In particular, traffic related pollution adversely affects lung function development.
228 children, mean age 8 years, were enrolled from 2 primary schools, located in different sites, for studying pollution related respiratory symptoms and/or diseases in different places of Milan with a different traffic-related exposure. The former (School 1) was located near a large park, the latter was located downtown, close to main crossroads (School 2). Daily levels of PM10 and PM2,5 (diameter <10micro-meters and 2,5micro-meters) were measured both outdoor and indoor outside the schools (in the school garden) and within common places (corridors), for 7 consecutive days during 2 different campaigns (winter and spring-summer). Children underwent skin prick testing for inhaled allergens, analysis of exhaled nitric oxid (FeNO) and spirometry.
The distribution of FeNO values was significantly different (p=0,02) between the two schools. In particular, the percentage of children with FeNO values <5ppb in school 1 was higher (almost double) than in school 2. In 73% of children attending the school located downtown FeNO concentration was between 5 and 20ppb. This difference, even if within normal values, could reflect a major bronchial eosinophilic inflammation in children exposed to higher concentration of pollutants.
The percentage of asthma exacerbations in the previous 12 months was higher in children from school 2 (p=0.05). On the contrary, the prevalence of persistent allergic rhinitis in children allergic to grass pollen was higher in school 1 (p=0.03). In particular, the latter children also had a greater activity limitation, due to rhinitis and concomitant conjunctivitis (p=0.03).
Interestingly, the highest recorded peak for PM10 occurred between 8:15 and 9:00 a.m., for 3 consecutive days, and was related to children arrival. This peak (>1000micro-grams/m$^3) didn’t seem to produce specific health effects, likely because of the usual PM10 composition in a park site, with a lower content of toxic or reactive components.
Hospital admissions, because of lower respiratory tract diseases (bronchitis, bronchiolitis, pneumonia) were more frequent during the winter campaign and in school 2, whereas otitis and allergic rhinitis or conjunctivitis, together with asthma, were more severe during the spring-summer period and in school 1, (p<0,05).
Present continuous on field monitoring of the various types of PM shows that:
-short durations pollution peaks, even reaching concentrations 20 folds above the fixed limits, have no consequences on children health and are induced by children’s arrival or movement.
-there is an enormous daily variability in PM10 concentration, among the daily mean value results, from the average of values, with a very high standard deviation (+30,+1000micro-grams/m$^3) and with various peaks.
Present findings show that, on the basis of the distribution of FeNO values, different degrees of respiratory function and bronchial inflammation were found in the 2 groups.
Traffic could be responsible at least in part for the different air quality, but individual susceptibility and seasonal changes are also major determinants of clinical outcomes.

This work was supported by the PROLIFE Project, City of Milan, Italy