More cargo, fewer ships cut container air pollution: LA study

BIGGER ships carrying more containers have cut air pollution on per-TEU basis in the Port of Los Angeles, according to a recent air quality study.

Nitrogen oxide containership emissions decreased six per cent and sulfur oxides by four per cent as the TEU numbers per ship increased from 3,272 in 2001 to 5,260 in 2005, a 44 per cent increase in container volume. This also resulted in a 61 per cent increase densification per vessel as the number of containership calls fell from 1,584 in 2001 to 1,423 in 2005, said a port statement.

The port study also said that shipping fleets had installed diesel oxidation catalysts on more than 580 pieces of shoreside equipment and 165 on-dock tractors and 800 other pieces of equipment ran on cleaner fuels, the statement said.

Regulations, voluntary reduction and operational improvements also contributed to a 17 to 27 per cent reduction in emissions per 10,000 TEU. "Port-wide emissions of sulfur oxides showed the strongest decreases," said the report.

Meanwhile the number of containers leaving the port by rail had more than doubled between 2001 and 2005, contributing to the 70 per cent increase in rail-related emissions though it is also accepted that railways produce less air pollution by reducing truck volume.