|Container ship at Port of Long Beach|
In a just-released analysis, the California Air Resources Board (ARB) has found that diesel PM emissions from the Ports of Los Angeles and Long Beach contributed some 21% of the total South Coast Air Basin PM emissions in 2002.
Together, the ports of Los Angeles and Long Beach form the third-largest port complex in the world.
The ARB study assessed the impacts from airborne particulate matter emissions from diesel-fueled engines associated with port activities at the Ports of Los Angeles and Long Beach (ports) located in Southern California.
The study focused on the on-port property emissions from locomotives, on-road heavy-duty trucks, and cargo handling equipment used to move containerized and bulk cargo such as yard trucks, side-picks, rubber tire gantry cranes, and forklifts. The study also evaluated the at-berth and over-water emissions impacts from ocean-going vessel main and auxiliary engine emissions as well as commercial harbor craft such as passenger ferries and tugboats.
Key findings from the study are:
Diesel PM emissions from the ports are a major contributor to diesel PM in the South Coast Air Basin. The combined diesel PM emissions from the ports are estimated to be about 1,760 tons per year in 2002, or 21% of the total SCAB diesel PM emissions in 2002.
Emissions from ship activities (transiting, maneuvering, and hotelling) account for the largest percentage of emissions at about 73%, followed by cargo-handling equipment (10%), commercial harbor craft vessels (14%), in-port heavy duty trucks (2%), and in-port locomotives (1%).
Diesel PM emissions from the ports result in elevated cancer risk levels over the entire 20-mile by 20-mile study area.
In areas near the port boundaries, potential cancer risk levels exceed 500 in a million. As you move away from the ports, the potential cancer risk levels decrease but continue to exceed 50 in a million for more than 15 miles.
Primary diesel PM emissions from the ports also result in potential non-cancer health impacts within the modeling receptor domain. The non-cancer health effects evaluated include premature death, asthma attacks, work loss days, and minor restricted activity days.
Based on this study, average numbers of cases per year that would be expected in the modeling area have been estimated as follows:
- 29 premature deaths (for ages 30 and older), 14 to 43 deaths as 95% confidence interval (CI);
- 750 asthma attacks, 180 to 1300 as 95% CI;
- 6,600 days of work loss (for ages 18-65), 5,600 to 7,600 as 95% CI;
- 35,000 minor restricted activity days (for ages 18-65), 28,000 to 41,000 as 95% CI.
“Hotelling” emissions from ocean-going vessel auxiliary engines and emissions from cargo handling equipment are the primary contributors to the higher pollution related health risks near the ports, accounting for about 20% of the total diesel PM emissions from the ports.
These emissions are responsible for about 34% of the port emissions related risk in the modeling receptor domain based on the population-weighted average risk. These emissions resulted in the largest area (2,036 acres) where the potential cancer risk levels were greater than 200 in a million in the nearby communities.
The second highest category contributing to cancer risk levels above 200 in a million was cargo handling equipment, which impacted a residential area of 410 acres and is responsible for about 20% of the total risk in the modeling receptor domain based on the population-weighted average risk.
Reducing emissions from these two categories will have the most dramatic effect on reducing the port emissions related risks in nearby communities.
Emissions from commercial harbor craft, in-port trucks, in-port rail, and ocean-going vessels (transit and maneuvering activities) account for a much smaller percentage of the near source risk, but are an important contributor to elevated cancer risk levels over a very large area.
While noting that the draft report highlights some uncertainties in modeling and risk assessment, the Diesel Technology Forum commented:
Ports are the final and potentially most challenging frontier of clean air policy due in large part to the magnitude and types of equipment in use, differing regulatory authorities and the complex nature of port operations.