Personal exposure to PM2.5 among high-school students in Milan and background measurements: The EuroLifeNet study

As part of the EuroLifeNet program we measured personal exposure to PM2.5 in 90 pupils attending three schools in Milan, over a three-week period spanning November and December 2006, using a portable light-scattering nephelometer. The primary aim was to investigate the relationship between personal exposure to PM2.5 and background measurements obtained from a fixed monitoring station. Pearson’s correlation coefficient between sampled daily mean exposures and reference values from background station varied from 0.64 to 0.75, with an overall value of 0.63, indicating good agreement. We also estimated that about 40% of the variability in the mean daily personal exposure at the three schools was due to variability in background exposure, the remaining 60% due to between-subject differences in exposures or to other sources of error.