Scientists at the European Commission's Joint Research Centre measured key air quality parameters in Mediterranean harbours. The measures show that sulphur dioxide emissions from shipping have sharply decreased in EU ports thanks to EU policies.

According to the Joint Research Centre (JRC), which measured key air quality parameters in Mediterranean harbours before and after the entry into force of the low-sulphur requirements in January 2010, sulphur dioxide emissions from shipping have sharply decreased in EU ports thanks to an EU policy which limits sulphur content in fuels for ships at berth or at anchor in ports. Measurements taken in a non-EU port showed that levels of this noxious substance remained the same. Provisional agreement between Council and the EP to reduce sulphur content of marine fuels was reached in May 2012.

In particular, the concentrations of sulphur dioxide were found to decrease significantly in three out of the four Mediterranean EU harbours that were investigated: Civitavecchia, Savona and Palma de Mallorca; the daily mean concentrations in all of the harbours decreased on average by 66%. In contrast, no decrease in sulphur dioxide was observed in the Mediterranean harbour of Tunis, and there was no reduction in any of the other air pollutants that were measured in all four harbours (Civitavecchia, Savona, Palma de Mallorca and Tunis).

The study carried out by the JRC shows that the decreases in sulphur dioxide are a direct consequence of the application of the EU requirements. The study also confirms a correlation between sulphur dioxide and chemical elements typically emitted from ship stacks which demonstrates that ships were the main source of sulphur dioxide in the harbours.