Polluting ships blamed for 60,000 deaths a year

Pollution from shipping is having a far greater impact on the air quality in coastal cities than previously thought and could be contributing to as many as 60,000 deaths a year, according to new research from scientists at the University of California in San Diego.

Published in the journal Proceedings of the National Academy of Sciences this week, the research reveals that 44 per cent of the sulphate pollution affecting coastal California could be traced directly to ships, rising to over 50 per cent on some days.

The researchers developed a "chemical fingerprinting" technique that allowed them to distinguish primary sulphates from ship smoke, which incorporates molecular oxygen, with sulphates from road traffic, which do not contain oxygen.

Mark Thiemens, Dean of the Division of Physical Sciences and a professor of chemistry and biochemistry at UCSD who headed the research, said that the results were a surprise, "because no one expected that the contribution from ships of solid sulphur-rich particles… would be so high".

Tiny sulphur particles can be carried long distances on the wind and are a major health hazard, blamed for respiratory ailments such as asthma and bronchitis, and considered a contributory factor for heart attacks and strokes.

The research will be seen as vindication for the recent introduction in California of new regulations, scheduled to take effect from July next year, that will require ships operating within 24 miles of the coast to switch to more expensive cleaner fuels. Similarly rules are expected to come into effect globally from 2015, but Thiemens hinted that the new research could herald a tightening of the standards.

"This [technique] will tell us whether California's new regulation requiring cleaner burning fuel 24 miles off the coast is having the effect it's intended to have," he said. "And because a large part of the world's population live in major cities with shipping ports – such as New York City, San Francisco, Hong Kong, Houston, and Singapore – and global shipping is expected to increase in the decades to come, this should help policy makers around the world make more informed decisions about improving the health of their citizens."