Air quality monitoring results
Elemental carbon is used as an indicator of diesel particulate matter (DPM) which is the soot produced by the combustion of diesel fuel. DPM has been designated a toxic air contaminant and known carcinogen by State of California health officials.
The results are proof-positive that air quality in the L.A. Harbor is improving as a result of substantial investments the Port, its tenants and other Port-related businesses have made in recent years by purchasing cleaner equipment and participating in a variety of emission-reduction initiatives. New State air quality regulations also have helped slash emissions from the big diesel engines that power the movement of cargo at the Port.
The result has been a major drop in concentrations of diesel exhaust in Port-area communities: in 2009, DPM, measured as elemental carbon, was 34 percent lower in San Pedro and 45 percent lower in Wilmington than in 2006. Concentrations of another key air pollutant, PM2.5 (particles less than 2.5 microns in size) met Federal and State standards in both 2008 and 2009, the first time that has occurred since monitoring began in the Port area.
Since 2005 the Port has operated four air quality measurement stations: one in San Pedro, another in Wilmington, and two inside the Port complex, including one in the middle of the active cargo handling area. The stations are located so as to measure air quality both in the port complex and in the communities downwind of the Port, where air quality is affected by emissions from the ships, trucks, terminal equipment, harbor vessels and train locomotives that move cargo through the nation’s largest container port.
The data from 2009 shows that elemental carbon concentrations in the air at the “source-dominated station,” which is the station in the midst of the cargo terminals, has fallen by 48 percent since 2006. Concentrations at the San Pedro and Wilmington stations have fallen by 34 percent and 45 percent, respectively. The decline is smaller at the community stations than at the in-port station because port sources make up a smaller fraction of the total emissions at those stations, so that declines in port sources have less effect.
Truck emissions, a perennial source of DPM in Port-area air, have been substantially reduced by the Port’s Clean Truck Program. Since the Clean Truck Program launched on October 1, 2008, the Port has distributed more than $70 million to spur the purchase of more than 2,700 cleaner, newer trucks. There are currently more than 6,500 trucks serving the San Pedro Bay port complex that meet or exceed the U.S. EPA 2007 heavy-duty truck emissions standards.
There are also the State’s restrictions on the sulfur content of fuel used in vessels and equipment operated at the port, the Port’s Alternative Maritime Power program, and the San Pedro Bay Vessel Speed Reduction program as key measures the State and the Port have used to tackle vessel emissions. The Port has also spent millions of dollars retrofitting cargo handling equipment and harbor craft engines with pollution control devices, and pioneering the use of alternative fuels and power systems. The air quality monitoring stations measure, in real time, ambient concentrations of several key air pollutants, including two sizes of particulate matter (PM10 or coarse particles, and PM2.5 or fine particles). In addition, twenty-four hour integrated samples of particulates are collected on filters every third day for detailed chemical analyses, which cannot be done with real-time monitors. Those analyses include measuring the amount of elemental carbon in the filters.
