Air Pollution


Air pollution from ships does not have the direct cause and effect associated with, for example, an oil spill incident. However, the cumulative effect of this type of air pollution contributes to the overall air quality problems encountered by populations in many regions, and also affects the natural environment, such as tough acid rain.

Preventing and combating air pollution caused by shipping has been a key focus of REMPEC’s work over recent years. The Centre has made great efforts to promote the ratification and implementation of the crucial international conventions, such as MARPOL Annex VI by the coastal states of the Mediterranean Sea. In addition, REMPEC is currently concentrating on contributing to the possible designation of Mediterranean Sea as an Emission Control Area for sulphur oxides (Med SOx ECA), by means of:


To tackle the hazardous effects of pollutants emitted from ships, in particular the Sulphur oxides (SOx) on human health and the environment in the Mediterranean Sea, various actors in the region, including REMPEC are uniting and combining their efforts to push forward the possible designation of the Mediterranean Sea as an Emission Control Area for sulphur oxides (Med SOx ECA).

As per Regulation 14 of MARPOL Annex VI, certain limits are imposed on the sulphur content of the fuel oil used on board ships, which are subject to a series of step changes over the years:

Outside an ECA established to limit SOx and particulate matter emissions

Inside an ECA established to limit SOx and particulate matter emissions

4.50% m/m prior to 1 January 2012

1.50% m/m prior to 1 July 2010

3.50% m/m on and after 1 January 2012

1.00% m/m on and after 1 July 2010

0.50% m/m on and after 1 January 2020*

0.10% m/m on and after 1 January 2015

* as required under regulation 14, a review as to the availability of the required fuel oil was undertaken. MEPC 70 (October 2016) considered an assessment of fuel oil availability and it was decided that the fuel oil standard (0.50% m/m) shall become effective on 1 January 2020 (resolution MEPC.280(70)).

In accordance with the Technical and Feasibility Study conducted by REMPEC, the designation of Med SOx ECA would result in the following outcomes:

  • emissions would be lowered by 78.7% for SOx and 23.7% for PM2.5, when comparing to the IMO sulphur cap (0.5%).
  • the potential to avoid 1,000 premature deaths, more than 2,000 cases of childhood asthmas.
  • acidification impacts on aquatic systems by wet sulphate and dry sulphate depositions would be reduced by 1.16% and 1.95% respectively, while the maximum percent decreases could reach 14.23% and 48.13% respectively in certain parts of the region.
  • a reduction in haze with improved visibility, which would be notably felt over the Straits of Gibraltar and northern Morocco and Algeria, and along the main shipping lane connecting the Straits of Gibraltar, Malta, and towards the Suez.

Legal Instruments

The key international regulatory framework regarding the requirements to control emissions from ships is established by Annex VI of MARPOL.


The ratification status of MARPOL Annex VI in the Mediterranean region: