The EuroLifeNet Study: How Different Microenvironments Influence Personal Exposure to PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt; among High-School Students in Milan

Alessandro Borgini,Paolo Crosignani,Martina Bertoldi,Cristian Ricci,Andrea Tittarelli

doi:10.4236/ojap.2015.41003

Abstract

Epidemiological studies show that long-term exposure to PM is associated with an increased risk of cancer. The EuroLifeNet study measured the personal exposure to PM2.5 in 90 pupils attending three schools in Milan, using a portable nephelometer, over a three-week period spanning November and December 2006. Background levels explained 40% of the variability of the exposure. Methods: As a second part of that study we analyzed the role of different microenvironments as determinants of personal exposure to PM2.5. Results: Exposure was influenced by the time of day, zone of the city and different microenvironments. Exposure was higher indoors than out, and indoors it was higher in the kitchen, particularly during cooking. In outdoor environments exposure was higher at bus stops where road traffic was heavy. Conclusions: Even though background concentration can be a good predictor of personal exposure to PM, students’ personal exposure is strongly influenced by different microenvironments and should be considered in population studies. The EuroLifeNet experience gives a contribution to personal exposure measure methodology.

Highlights

Many epidemiological studies show that air pollution and long-term exposure to atmospheric particulate matter (PM) are associated with an increased risk of specific cancers [1]-[3].Studies on school-age children show an association between PM and adverse effects on respiratory function [4]-[7]
Descriptive statistics and histogram plots of PM2.5 exposure over the whole observation period showed that exposure was skewed for every microenvironment under analysis (Figure 1, Figure 2 and Table 1)
Descriptive statistics (Table 1) indicated that PM2.5 exposure was generally higher in indoor microenvironments than outdoors

Summary

Introduction

Many epidemiological studies show that air pollution and long-term exposure to atmospheric particulate matter (PM) are associated with an increased risk of specific cancers [1]-[3].Studies on school-age children show an association between PM and adverse effects on respiratory function [4]-[7]. Results: Exposure was influenced by the time of day, zone of the city and different microenvironments. PM2.5 exposure was calculated considering the sampling day, time of day, zone of the city and pupils. All these factors introduced in a nested generalized linear model resulted in an R2 of 0.61 which corresponds to an explained variance of about 60%, the remainder being explained by other sources of variability such as micro environmental exposure or other random factors. The statistical comparison among microenvironments (Table 2) showed that PM2.5 exposure was significantly different for some microenvironments Among these microenvironments PM2.5 exposure was high at bus stops and in the kitchen where the excesses were respectively 12.82 (95% CI, 2.2 - 23.4) and 29.38 (95% CI, 25.5 - 33.6) μg∙m−3. PM2.5 exposure appeared higher for public buses than private cars: the difference was 9.9μg∙m−3 (95% CI, 2.1 17.7).

Methods

Discussion

Conclusion