Stuart Gary of ABC Science reports that shipping in Australia may produce up to 30% of all nitrogen oxide and 20% of total sulphur emissions, according to a new study.

While these are non-greenhouse gases, they produce photochemical smog and airborne particulates that can contribute to health issues. There are serious cardiovascular and pulmonary concerns. Further to this, their environmental impact causes a change in atmospheric chemical processes and can cause acid rain, amongst others.

Further exacerbating the problem is that the ports in Sydney, Brisbane, Melbourne and Perth all suffer seasonal onshore winds carrying the pollutants from shipping into the airsheds of these major urban areas. It is time to reassess measurements of these pollutants as well as the impact on human health.

The researchers measured the emission levels of a coastal cement carrier MV Goliath sailing between Devonport in Tasmania to Melbourne. Then they calculated exhaust emission data from different types of vessels docking at Australian ports, comparing different fuels, running speeds and engine designs. The results were astounding as no-one expected the ships to be such significant contributors.
Many ships visiting Australia use cheap fuels derived from the residue of the crude oil refining process. These residue oils are likely to have a higher sulphur content than the global average.

Other countries, including the US, Canada and the Europe through its North and Baltic Sea ports have imposed restrictions on sulphur content. And shipping is big business with over 753 million tonnes of international exports passing through Australian ports annually, making up a 10th of global shipping.

While it is the most environmentally friendly and fuel efficient way of moving freight, it is still not harmless. The scientists want further research on the impact of sulphur and nitrogen oxide on the atmosphere across remote higher latitude regions of the southern hemisphere.

Source: abc.net.au