Atmospheric pollution from ships and its impact on local air quality at a port site in South America

The present work aims to estimate the impacts of SOx, NOx and PM emissions caused by ship traffic on air quality in Tubarão Port during the year of 2015. It is strategically located in Vitoria Metropolitan Area, state of Espírito Santo, on the southeast coast of Brazil and this area presents big companies (steel maker, iron ore pellets facility, petroleum etc.) that use ships for international trade. The work was carried out in two parts: inventory of emissions and modeling of atmospheric dispersion. The emissions inventory used the latest methodology proposed by the European Environmental Agency (EEA), applying information about vessel types, engine type and fuel, navigation phase and engine mode, fuel sulfur content, gross tonnage and age of ships. This information was estimated or obtained from the technical and scientific literature, using online monitoring platforms of vessels and by the agency responsible for waterway transportation in Brazil (National Agency of Waterway Transportation). Emissions were estimated for each ship in the port terminals of the study region, considering their characteristics and the times recorded in the navigation phases (waiting, maneuvering and berthing). The Gaussian atmospheric dispersion model AERMOD was used to simulate the scenarios of concentrations of the pollutants that were estimated considering only ship emissions. The discrete points adopted to analyze the impact of the pollutants are in the same coordinates where the air quality monitoring stations are installed in the study region. Modeling results were evaluated using local air quality monitoring data to quantify the contribution of the ship traffic emissions in the region, verifying scenarios of maximum concentrations and means in the year of the study. The emission inventory showed that large ships had the highest emissions rates. Ships in the anchorage zones, where the ships wait to dock, that they occur more emission because there is an average time bigger than in the other phases. The fuel that causes the highest impact is the BFO.