Union Pacific's efforts to reduce air pollution around the busy California ports of Long Beach and Los Angeles have been recognized.

The Harbor Association of Industry and Commerce of Southern California recently gave the Omaha-based railroad its "Salute to Industry" award.

UP says its fleet of locomotives is the cleanest of any North American railroad.

Since 2000, Union Pacific has added more than 3,300 fuel-efficient, long-haul locomotives and has retired more than 2,200 older locomotives.

Union Pacific also uses Genset switching locomotives in its California rail yards to help limit pollution.