Development of an integrated modelling-measurement system for near-real-time estimates of harbour activity impact to atmospheric pollution in coastal cities

Several studies focused on harbour impact on air quality of port-cities showing that maritime emissions could be comparable to traffic emissions of a medium-size town having relevant impact on air quality nearby the harbours. In order to plan efficient mitigation strategies, environmental and port authorities have an increasing need of reliable tools for investigating the impact of ships traffic and harbour logistics on atmospheric pollutants. In this work a system based on the integration of measurements collected using a network of low-cost on-line sensors with local scale dispersion modelling was developed. It was implemented, as a pilot action, in the information and management software of the Bari harbour (SE Italy). It can operate in near-real-time, in forecast mode, and on archived data for long-term assessments. It was tested studying the impact of the Bari harbour for the year 2018. The lowest impact was observed for CO, being the pollutant with the lowest share of the contribution of ships (between 8% and 68%) compared with the total harbour contribution. The impacts on PM2.5 and PM10, are larger arriving up to 11.8% of concentrations in the harbour area with an influence of shipping between 44% and 97%. The impact on SO2 is almost solely due to ships and it arrives up to 80% in the harbour area. The impact on NOx ranges from a few percent in the urban area up to 40% in the harbour area and it is the pollutant of major concern regarding compliance with air quality standards.