Magnetic properties, concentration of PM1 and carbonaceous aerosols in primary schools

Abstract:

The exposition to particulate matter (PM) has well known health hazards and the finer fractions are the most dangerous ones. The use of magnetic methods to investigate the PM has been proved successful, and those methods are sensible to the finer fractions (superparamagnetic, SP) of the iron oxides. Children are especially at risk, since their specific physiology may result in a higher absorption of pollutants from air. In order to access the exposition of children to PM, we investigate the concentration and the difference between indoor and outdoor environments. We use active (concentration of carbonaceous aerosols and PM on air) and passive methods (environmental magnetism protocol comprising magnetic susceptibility, saturation magnetization and SP concentration), both sampling indoor and outdoor environments in primary schools from southwest France. The active monitoring points out that the schools are subject to emissions from combustion in the transport system, with higher concentrations outdoors for PM and black carbon. Organic carbon indicates poor ventilation in one of the schools during winter. When comparing both schools, the one closer to the main traffic source has higher concentrations of PM and iron oxides, specially by the SP fraction. Magnetic results show higher concentration in outdoor environments. Accumulation of PM in poor ventilated rooms can also be observed. The magnetic methods proved themselves in this study to be effective, supplementing the information provided by the air quality active monitoring.