Fingerprinting particulate matter for urban monitoring and source apportionment techniques.

Among air pollutants, particulate matter (PM) poses the greatest risk to public health. Atmospheric PM is currently monitored by a network of air monitoring stations, but its limited spatial resolution impedes to properly monitor the high spatial variability in PM local exposure. On the other hand, urban vegetation works as a reliable passive PM collector, as it provides a natural surface for deposition and immobilization of pollutants. In this research project, urban green is thus used as a bio-indicator for atmospheric PM (biomonitoring), where each leaf plant can work as a monitoring station per se. Within airborne PM, iron and other metals are of particular interest. Therefore, magnetic biomonitoring of leaves has been extensively used as a rapid and cost-effective tool to assess urban PM exposure, however, the discrimination of PM sources based on magnetic analyses remains yet a less explored topic. PM source attribution mainly depends on the chemical characteristics (composition and structure of the particles), size distribution and even shape properties, therefore, a component of particle analysis is also necessary to understand the different sources of PM. The strategy of this project is based on PM fingerprinting the major urban PM sources (e.g. roadside and train traffic) in terms of its magnetic signatures, composition and microscopic form, and on how the different magnetic parameters can be used to identify them in the mixed-source urban environment. The main goal is then to investigate the applicability of using magnetic biomonitoring of urban leaves as an effective source apportionment methodology/tool for PM exposure. The application of such a methodology would help on delineating high-polluted PM areas while understanding their major PM emission sources, which can be of great use for e.g. impact assessment studies and policy implementation of targeted PM mitigation strategies.

Keywords:PARTICULATE MATTER, ENVIRONMENTAL MONITORING, AIR POLLUTION

Disciplines:Sustainable chemistry, Aquatic sciences, challenges and pollution, Environmental science and management