"DULUTH, MINN. -- A horn blasts, seagulls screech and tourists clap as the longest ship in the Great Lakes, the 308-meter Paul R. Tregurtha, glides through Duluth's canal and heads into Lake Superior, loaded down with coal bound for Midwestern power plants.
Piles of crushed limestone, salt, iron ore and coal line the shores of the Great Lakes' busiest port, destined to forge steel, de-ice roads and build skyscrapers throughout the heartland. The towering grain elevators along the harbor's shores are stuffed with wheat and soy waiting for the trip out the St. Lawrence Seaway to the Atlantic Ocean, then on to Europe, North Africa or South America.
Underlying this show of commercial strength is a maritime industry many see as fragile, threatened not only by a weak economy but also by broader environmental initiatives. The emissions from these ships -- the only mode of transportation not under new federal air pollution regulations -- have been linked to increased levels of heart and lung disease."