Researchers for the National Oceanic and Atmospheric Administration and the University of Colorado say ship pollutants affect both global climate and the health of people living along coastlines.

The authors estimate that commercial vessels emit about 2.2 million pounds of particle pollution each year.

Lead author Daniel Lack says that since more than 70% of shipping traffic takes place within 250 miles (400 kilometers) of the coastline, it's a significant health concern for coastal communities.

Lack and colleagues analyzed exhaust from more than 200 commercial vessels during summer 2006.

The findings appear online this week in the Journal of Geophysical

Research.