Maritime Shipping Contributes to Harmful Air Pollution

The National Oceanic and Atmospheric Administration (NOAA) reports in a new study that marine shipping accounts for up to half as much particulate matter pollution as cars and trucks. Coastal residents living near busy ports are affected by these impacts to local air quality.

According to the University of Colorado at Boulder sponsored study, commercial vessels emit 0.9 teragrams, or about 2.2 million pounds, of particle pollution each year. The study’s findings are being published in the Journal of Geophysical Research.

Lead author of the study Daniel Lack says, “Since more than 70 percent of shipping traffic takes place within 250 miles of the coastline, this is a significant health concern for coastal communities.”

Marine vessels emit sulfate particles and soot. Ship emissions are dependent on the sulfur content and quality of the fuel burned. There is international regulation of vessel emissions mandated by the International Convention for the Prevention of Pollution from Ships, but many ships still use high-sulfur content fuels.

Researchers found that soot generation by vessels was effected by engine speed and lubricants used. It was found that particles produced from burning low sulfur fuel remain airborne for a longer periods of time and soot generated by vessels is not likely to form cloud droplets, so it also remains in the air for an extended time. Currently naturally occurring precipitation is the only way suspended particles of pollution are cleaned from the atmosphere.