Sophisticated Clean Air Strategies Required to Mitigate Against Particulate Organic Pollution.

Area of Science:

• Atmospheric Chemistry
• Environmental Science
• Air Quality Monitoring

Background:

• Transboundary air pollution mitigation measures have shown success, particularly for sulphur pollution in the North Atlantic region.
• The North Atlantic serves as a crucial area for monitoring Northern Hemisphere pollution levels.
• Long-term data from 1980-2014 reveals significant reductions in airborne sulphur (SO4 and SO2).

Purpose of the Study:

• To analyze the long-term trends of atmospheric pollution in the NE-Atlantic.
• To characterize the composition of PM1 aerosols under varying pollution conditions.
• To highlight the need for improved monitoring and policy for carbonaceous aerosols.

Main Methods:

• Analysis of a 35-year record (1980-2014) of atmospheric sulphur pollution.
• Observation data from the Mace Head research station on the Irish coast.
• Characterization of PM1 aerosol composition, including sulphate and carbonaceous components.

Main Results:

• A 72-79% reduction in annual-average airborne sulphur pollution (SO4 and SO2) was observed.
• The NE-Atlantic was classified as 'clean' 64% of the time, with sulphate dominating PM1.
• Under polluted conditions, carbonaceous aerosols (organic matter and black carbon) prevailed, increasing with pollution levels and comprising 60-90% of PM1 mass.

Conclusions:

• While sulphur pollution has decreased, carbonaceous aerosols represent a growing concern in air quality.
• The diverse sources and nature of carbonaceous aerosols necessitate advanced characterization and source apportionment.
• Current regulatory air quality networks do not measure these critical carbonaceous components, hindering effective pollution control strategies.