Browsing by Author "Charres, Isabella"
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- Seasonal variation in exposure to particulate matter among children attending different levels of education: comparison of two dosimetry modelsPublication . Charres, Isabella; Cipoli, Yago Alonso; Furst, Leonardo; Vicente, Estela D.; Casotti Rienda, Ismael; Lazaridis, Mihalis; Feliciano, Manuel; Alves, CéliaExposure to particulate matter (PM) has been associated with several adverse health outcomes. Studies indicate that children may be exposed to much higher concentrations of PM at school than in other environments. There exists very little data on the deposited dose of PM while children attend classes. This study was carried out in a school located near an industrial complex in Portugal and attended by children aged 3–12 years. Indoor PM10, PM2.5 and PM1 were measured over two seasons in classrooms representing different school year groups. Particle deposition fractions in the respiratory tract, as well as the deposited doses, were calculated using the Multiple-Path Particle Dosimetry (MPPD) and the Exposure Dose Model (ExDoM2). Both models were implemented assuming an 8-hour exposure scenario to represent the school day. In general, differences in PM concentrations were observed depending on room occupancy periods and season. The highest mean PM2.5 concentration was recorded in winter when the classroom was vacant (23.7 ± 20.5 μg m-3), while the highest mean PM10 level was observed in spring during school hours (61.7 ± 24.2 μg m-3). Regardless of the dosimetry model, the highest deposition of PM10 and PM2.5 was in the upper region, while the lowest was in the tracheobronchial (TB) region. The results indicate that deposited dose and deposition fraction in spring may be more harmful to pupils’ health than in winter. PM10 presented the highest doses, ranging from 54.2 to 128 μg and from 83.9 to 185 μg, according to MPPD and ExDoM2 estimates, respectively.
- Seasonal variations of size-classified aerosol-bound elements in school environments and risk factors for the prevalence of atopic diseases among pupilsPublication . Charres, Isabella; Lucarelli, Franco; Feliciano, Manuel; Furst, Leonardo; Alves, CéliaFive-stage Sioutas impactors were used to collect particulate matter (PM) in 4 classrooms and the playground of a school with various educational levels near the largest industrial chemical complex in Portugal. Monitoring was carried out over a total period of 8 weeks split equally between winter and spring. Samples were analysed for its elemental composition by PIXE. The prevalence of respiratory symptoms in schoolchildren was assessed by applying the International Study of Asthma and Allergies in Childhood (ISAAC) standardised questionnaire. The mass concentration of quasi-ultrafine particles (PM0.25) was higher in winter, but lower than those reported in other studies. Elements accounted for 15.3–17.3 % and 25.6–34.1 % of the total PM10 mass in winter and spring, respectively. Elements such as K, S, Zn, Cu and Br presented a dominant mode in PM0.25, while Al, Mg, Ca, Fe and Si peaked at 2.5 μm. Throughout the campaign, Cl was the main component of the mass of PM greater than 0.5 μm in the schoolyard, while in classrooms Ca constituted the most abundant element of PM2.5-10. The results indicate that soil dust, cleaning products, biomass burning, traffic, the chemical complex and railway affected PM levels at the school. Taking paracetamol and living near roads with intense traffic of heavy vehicles were found to be statistically significant predictors of asthma symptoms, while the frequent consumption of antibiotics and children exposure to parental smoking during the first year of their life were found to increase the odds of developing symptoms of rhinitis.