Harmful diesel emissions fell sharply at the Port of Los Angeles and in surrounding communities, according to data accumulated from air monitoring stations in 2009. The data released Tuesday show a 48 percent reduction in diesel particulate matter compared to 2006 in the immediate cargo-handling areas of the port. Also, PM concentrations were down 34 percent in the community of San Pedro and 45 percent in Wilmington. … Since (2006), programs have been implemented to retrofit cargo-handling equipment and harbor craft, burn low-sulfur fuel in ocean-going vessels, reduce vessel speeds within 20 miles of the coast and replace older trucks with about 6,500 clean-diesel and alternative-fuel trucks that meet or exceed the Environmental Protection Agency’s standards for 2007-model engines.