Child exposure to indoor and outdoor air pollutants in schools in Barcelona, Spain

Abstract

Proximity to road traffic involves higher health risks because of atmospheric pollutants. In addition to outdoor air, indoor air quality contributes to overall exposure. In the framework of the BREATHE study, indoor and outdoor air pollution was assessed in 39 schools in Barcelona. The study quantifies indoor and outdoor air quality during school hours of the BREATHE schools. High levels of fine particles (PM2.5), nitrogen dioxide (NO2), equivalent black carbon (EBC), ultrafine particle (UFP) number concentration and road traffic related trace metals were detected in school playgrounds and indoor environments. PM2.5 almost doubled (factor of 1.7) the usual urban background (UB) levels reported for Barcelona owing to high school-sourced PM2.5 contributions: [1] an indoor-generated source characterised mainly by organic carbon (OC) from organic textile fibres, cooking and other organic emissions, and by calcium and strontium (chalk dust) and; [2] mineral elements from sand-filled playgrounds, detected both indoors and outdoors. The levels of mineral elements are unusually high in PM2.5 because of the breakdown of mineral particles during playground activities. Moreover, anthropogenic PM components (such as OC and arsenic) are dry/wet deposited in this mineral matter. Therefore, PM2.5 cannot be considered a good tracer of traffic emissions in schools despite being influenced by them. On the other hand, outdoor NO2, EBC, UFP, and antimony appear to be good indicators of traffic emissions. The concentrations of NO2 are 1.2 times higher at schools than UB, suggesting the proximity of some schools to road traffic. Indoor levels of these traffic-sourced pollutants are very similar to those detected outdoors, indicating easy penetration of atmospheric pollutants. Spatial variation shows higher levels of EBC, NO2, UFP and, partially, PM2.5 in schools in the centre than in the outskirts of Barcelona, highlighting the influence of traffic emissions. Mean child exposure to pollutants in schools in Barcelona attains intermediate levels between UB and traffic stations.

Exposure of Children to Ultrafine Particles in Primary Schools in Portugal

“…In comparison with a study conducted in 37 classrooms in Canada (Weichenthal et al, 2008), UFP in Portuguese schools were approximately 1.6-to 1.9-fold higher. In contrast, studies on UFP in 39 primary schools in Spain Rivas et al, 2014), 7 primary schools in Greece (Diapouli et al, 2007), and 2 primary schools in Italy (Buonanno et al, 2013b) reported 1.2-to 3.5-fold higher values of UFP. Similarly, studies from other non-European countries such as in California (Mullen et al, 2011), Australia (Morawska et al, 2009), and South Korea (Kim et al, 2011) noted considerably higher levels of UFP than the findings obtained in the cur-rent investigation.…”

Assessment of Indoor-Outdoor Particulate Matter Air Pollution: A Review

“…In working environments, PM size distribution, concentrations, and chemical properties are even more site-specific than in residential ones as these depend on the used materials, productive methods, and working typologies. Extensive literature on school environments, partially for assessing children's exposure (i.e., the tendency for health impairments, and the large percentage of daytime spent in those spaces) and as a major working sector for the number of employees, is found [14,[33][34][35].…”

A Pilot Investigation of PM Indoor/Outdoor Mass Concentration and Chemical Analysis during a Period of Extensive Fireplace Use in Athens

“…Among them, Fe strongly dominates in both indoor and outdoor air (81% and 82% respectively), followed by Zn (12% both indoors and outdoors) and the other metals analyzed, with contribution lower than 3%, indicating the similar elemental consistency of indoor and outdoor particles. Fe is classified among mineral components, Cu among traffic-related components (brake pad abrasion tracers), Ni among heavy fuel-oil combustion components (mostly from shipping emissions) and Cd, Zn, Cr and Pb among industrial elements (Rivas et al, 2014). Among the metals studied, Ni and Cd are regulated through WHO guidelines (WHO, 2000) with a maximum value of 1000 ng m -3 for Ni and 5.0 ng m -3 for Cd.…”