A project analyzes the microparticles in European subway

Hexacomm  is a European Project aimed at studying the risks associated with human exposure to particles in the air. One of its sub-projects will analyze the exposure of passengers to the particles in the subway of some European cities: Barcelona, Prague, Athens and Porto.

Container with the equipment for sampling, in the Athens subway.Twelve doctoral theses will be developed in the frame of the HEXACOMM project (acronym of Human Exposure to Aerosol Contaminants in Modern Microenvironments), all of them aimed at studying the air quality in different indoor environments. The theses are funded by the Marie Curie Programme, in the EU's Seventh Framework Programme.

Two theses will be developed at the CSIC’s Institute of Environmental Assessment and Water Research (Instituto de Diagnóstico Ambiental y Estudios del Agua - IDAEA), by the group of  atmospheric inorganic geochemistry, which is led by CSIC scientists Xavier Querol and Andrés Alastuey. One of these theses is an Hexacomm sub-project, “Personal exposure to PM during commutes: underground systems”. Its goal is to analyze the microparticles in the subway environment, both on the platforms and inside the trains.

Citizens in big cities spend a considerable amount of their time commuting in public transport, The use of the subway, and in general public transport, contributes to reduce road traffic. In this sense, subway transport is considered a cleaner transport system. Nevertheless, previous studies found that levels of particulate matter suspended in air in subway networks are relatively high and could be reduced. These micro particles are so small that they can be inhaled by people.

The team of the Institute of Environmental Assessment and Water Research (Instituto de Diagnóstico Ambiental y Estudios del Agua - IDAEA) of the CSIC coordinates this Project, for which an 'ad-hoc' protocol for taking samples has been established, as “the results can be directly compared if the samples have been taken and analyzed in a similar way”, explains María Cruz Minguillón, a scientist at the IDAEA-CSIC. For the same reason, all the samples are being analyzed in the IDAEA-CSIC laboratories.

The scientists are studying the particle concentration, the sizes of the particles and their chemical composition. Besides, some samples taken on the platforms and inside the trains are biologically analyzed, with the collaboration of the Laval University (Canada) and the Centre for Advanced Studies of Blanes (CEAB) of the CSIC.

Sampling campaigns: from weeks to several months

The Barcelona subway system comprises eight subway lines, at different depths, with different tunnel and station designs and train frequencies. The CSIC scientists have developed an extensive measurement campaign of eight months which was carried out in more than twenty stations and inside the trains on six of the lines. Specific tests have been performed to study variations in air quality depending on ventilation conditions both on platforms and inside the trains. This research has counted on the collaboration of TMB (Transports Metropolitans de Barcelona) and funded by the R+D Spanish Plan (METRO project).

The Prague subway system campaign was short on time, but included several types of measurements, similar to Barcelona. The campaign was a collaboration between the IDAEA-CSIC and the Institute of Chemical Process Fundamentals (ICPF) from Czechoslovakia.

In Athens, the sampling campaign lasted for three weeks, which enabled the collection of  relevant information which was directly comparable to the information from Barcelona subway, both from stations and trains. The campaign was a collaboration between IDAEA-CSIC, N.C.S.R. Demokritos (Greece), Technical University of Crete (Greece), and University of Essex (UK). Scientific publications are currently in preparation.

In the Porto subway, the campaign lasted for three weeks, which allowed the collection of relevant data. This campaign was a collaboration between IDAEA-CSIC and the University of Aveiro.

More information: http://hexacomm.nilu.no/