Fine particles and children's respiratory function in two primary schools in Milan, Italy

Background: Few data exists about relationship between respiratory function and different types of air particulates. Aim: To relate fine particles concentrations to children's respiratory function and inflammation. Methods: We selected two schools in Milan, school 1 located near a large park and school 2 downtown. From September 23th to October 3rd 2008, we sampled in and outdoor PM1, PM2,5 and PM10 (mcg/m3) by Optical Particle Counters (OPC 1,107 environcheck and OPC 1,108 dustcheck). We enrolled 232 children; 149 attending school 1, 83 school 2. All underwent spirometry and exhaled fraction of nitric oxide (FeNO) dosage. Results: Fine particles [mean (SD)] are significantly higher in school 2, except schooltime (7:30-18:30) indoor PM10, that increases in both schools (table). Respiratory function is normal in all children but the percentage values (mean [SD] of FEV1, FVC and PEF are different in the two schools (106,1 [11,85] vs 102,1 [12,87] p=0,007; 100,4 [10,77] vs 95,84 [11,45] p=0,011; 92,8 [14,62] vs 88,6 [13,63] p=0,31). Mean (SD) concentration of FeNO (ppb) is normal in both (14,5[9,16] vs 17,1 [12,7] p=0,456). Conclusion: Although PM10 indoor is higher in school 1, respiratory function is better. PM10 couldn't be the most useful indicator of air quality and its effects on children pulmunary health.