'Nano' dust in Venice: 9% come from maritime traffic

Scientists from Ca’ Foscari University of Venice have completed the first study on nanoparticles emitted by maritime traffic in Venice. According to preliminary results, between 7 and 9 percent of the nanoparticles , with a diameter of less than 0.1 microns (one ten thousandth of a millimetre), are due to the discharge from boats. This type of traffic contributes more to 'nano' particulate matter than to PM2.5 or greater.

The data comes from sampling carried out between August and November 2018 with a specific piece of equipment positioned in the ARPAV control unit in Sacca Fisola, on the Giudecca Canal. The results help broaden scientific knowledge on air pollution in Venice, one of the Italian cities worst affected by smog.

Previous studies had already shown that the impact of maritime traffic increases with decreasing particle size, but only few studies had been undertaken and limited at most to a size of 1 micron. Nanoparticles, however, can penetrate deeper into the respiratory system, with possible more harmful consequences for our health.

“We asked ourselves how much of the particulate matter smaller than one micron was due to the presence of ships in our city,” explains Elena Gregoris, researcher in Analytical Chemistry, “confirming that maritime traffic contributes more to nanoparticles than larger particles and calculating the contribution: whilst 'naval' nanoparticles reach 9% of the total, for larger particles they reach no further than 3 percent .”

The research was made possible thanks to the Italy-Croatia Interreg programme and is part of the recently concluded ECOMOBILITY project, funded with €830,000 and coordinated by Ca’ Foscari.

The cross-border dimension of the project allowed comparison with another port city, Rijeka (Croatia), where the impact of maritime traffic is lower than that measured in Venice. Even in the Croatian port, nanoparticles had a higher impact than the larger particulate matter: "nano" particles reached 2 percent, compared to 0.5 percent for larger particles.

The aim of the project was to promote the environmental sustainability of road and sea transport in coastal areas, using an eco-compatible approach. In addition to the analysis on pollution, the international team has developed a veritable instrument useful to local administrations.

“The most visible result of our project,” explains Salvatore Orlando, Professor of Informatics in the Department of Environmental Sciences, Informatics and Statistics, “is the EcoMobility smartphone application. This application is for smartphones and other portable devices and gives people real-time information on the pollution in the city and enables them to plan ecological journeys.” The app is available via desktop at the link web.ecomobility.dsi.unive.it.

“The pollution data come from the ARPAV control units and are not just used for the application,” adds Andrea Gambaro, Professor of Analytical Chemistry and project coordinator. “We have also created a support system for urban traffic operators, who receive warnings in real time if they exceed certain pollution thresholds. In this way, the authorities in charge can intervene in advance to prevent over-pollution.”

The University and Municipal Authority of Rijeka (Croatia) and the Veneto Regional Authority and the Institute of Atmospheric and Climate Sciences of the National Research Council (CNR-ISAC) (Italy) also participated in the project.