Short-sea shipping contributions to particle concentration in coastal areas: Impact and mitigation

Abstract

• Short-sea shipping visibly contributes to particles concentrations in coastal areas. • The bottom-up model predicts consistent particle number concentration, PN, values. • Differently, contribution of ships on PM2.5 cannot be inferred by bottom-up model. • Existing regional fuel quality restrictions mostly reduce PM2.5 emissions. • Cleaner fuels and available after-treatment systems highly reduce PN/PM2.5 levels. Several studies indicate that short-sea shipping is an important source of air pollution for coastal areas and port cities. This paper reports results of a non-reactive particles dispersion model and a new set of experiments implemented for the Channel of Procida (Italy), an area with a high signal-to-noise ratio, due to intense marine traffic and low background pollution. The model successfully predicts particle number concentrations but underestimates PM 2.5 data. Model and experiments show that thanks to the EU policies on marine fuels, the Channel of Procida already has good air quality levels. Besides, the paper demonstrates that fostering the use of LNG or methanol or the application of an exhaust-gas-cleaning-system may allow reducing particles emissions well above 90%. The reliability of control strategies and the benefits for the population suggest that the introduction of regulations on particles emissions for ships can be a realistic option for the future environmental policy agenda.