Marine engineering department
AnIntroduction to Water Pollution
Water has the remarkable ability to renew and cleanse itself. When waste materials are deposited into a receiving stream, they often settle out, break down, or become diluted in the stream. However, pollution can occur if too much of a substance or too many substances are discharged so that it overwhelms the capacity of the stream to assimilate the substances or cleanse itself. Water pollution may also occur if even just a liittle of a highly toxic substance is discharged into a receiving stream (e.g., dioxin). Water pollution can be classified into two main categories: point source pollution and nonpoint source pollution.
Marine ports are major hubs of economic activity and major sources of pollution. Enormous ships with engines running on the dirtiest fuel available, thousands of diesel truck visits per day, mile-long trains with diesel loco- motives hauling cargo, and other polluting equipment and activities at marine ports cause an arraay of environmental impacts that can seriously affect local communities and the environment. These impacts range from increased risk of illness, such as respiratory disease or cancer, to increases in regional smog, contamination of water, and the blight of local comm
Most major ports are undergoing expansions to accommodate even greater cargo volumes. The growth of international trade has resulted in corresponding rapid growth in the amount of goods being shipped by sea. Despite the enormous growth within the marine shipping sector, mostpollution prevention efforts at the local, state, and federal levels have focused on other pollution sources, while the environmental impacts of ports have grown.
Marine ports are now among the most poorly regulated sources of pollution. The result is that most ports are heavy polluters, releasing largely unchecked quantities of health-endangering air and water pollution, causing noise and light pollution that disrupts nearby communities, and harming marine habitats.
AIR POLLUTION FROM PORT OPERATIONS
The diesel engines at ports, which poweer ships, trucks, trains, and cargo-handling equipment, create vast amounts of air pollution affecting the health of workers and people living in nearby communities, as well as contributing significantly to regional air pollution. More than 30 human epidemiological studies have found that diesel exhaust increases cancer risks, and found that diesel exhaust is responsible for 71 percentof the cancer risk from air pollution. More recent studies have linked diesel exhaust with asthma.2 Major air pollutants from diesel engines at ports that can affe
Primary Air Pollutants of Concern
Particulate matter pollution (PM), ranges from coarse dust kicked up from dirt roads to tiny sooty particles formed when wood, gasoline or diesel is burned. At ports, construction and daily operations often create coarse PM, but it is the tiniest PM that causes the greatest health hazards. Much of this fine PM—so small it is invisible to the eye-comes from diesel engine exhaust. Less than 1⁄20 the diameter of a human hair, fine PM can travel deep into the lungs, landing in the delicate air sacs where oxygen exchange normally occurs.
Volatile organic compounds (VOCs) are often toxic, and when they evaporate into the air they can react with other pollutants to form ground-level ozone, commonly referred to as smog. Common VOCs produced by diesel engines include benzene,
1,3-butadiene, formaldehyde, and toluene, each of which poses significant health risks, including cancer and birth defects.7
Nitrogen oxides (NOx) are a family of chemicals, including nitrogen dioxide, nitric acid, nitrous oxide, nitrates, and other related compounds. They can cause a wide variety of health problems, including respiratory distress, and react with VOCs in the atmo
Ozone, also known as smog, is a reactive gas produced when VOCs and NOx interact in sunlight and split apart oxygen molecules in the air. The layer of brown haze it produces is not just an eyesore, but also is a source of serious illnesses. Ozone is extremely irritating to the airways and the lungs, causing serious damage to the delicate cells lining the airways. It contributes to decreased lung function, increased respiratory symptoms, asthma, emergency room visits, and hospital admissions.10
Ozone can cause irreversible changes in lung structure, eventually leading to chronic respiratory illnesses, such as emphysema and chronic bronchitis.11
Burning fuels that contain sulfur, such as diesel and especially marine diesel fuels that have a high sulfur content, produce sulfur oxides (SOx). Sulfur oxides include sulfur dioxide, PM, and a range of related chemical airpollutants. SOx react with water vapor in the air to create acids that irritate the airways, sometimes causing disc
In addition to the pollutants discussed above, there are other air pollutants that threaten public health that are not discussed in this report, including carbon monoxide (CO), formaldehyde, heavy metals, dioxins, and pesticides used to fumigate produce.
The Effect of Port-Related Air Pollution on Human Health
The health effects of pollution from ports may include asthma, other respiratory diseases, cardiovascular disease, lung cancer, and premature death. In children, these pollutants have been linked with asthma and bronchitis, and high levels of the pollutants have been associated with increased school absenteeism and emergency room visits. In fact, numerous studies have shown that children living near busy diesel trucking routes are more likely to suffer from decreased lung function, wheezing, bronchitis, and allergies.13,14,15
Many major ports operate virtually next door to residential neighborhoods, schools, and playgrounds. Due to close proximity to port pollution, nearby commu- nities face extraordinarily high health risks from port air pollutants. Many of these areas are low-income communities of color, raising environmental justice concerns.
In the Los Angeles area, oceangoing ships, harbor tugs, and commercial boats such as passenger ferries emit many times more smog-forming pollutants than all power plants in the Southern California region combined.16 And growth forecasts predicting trade to triple by 2020 in the Los Angeles region mean that smog-forming emissions and diesel particulatepollution could severely increase in an area already burdened by the worst air quality in the nation.
Average Contributions of Various Port-Related Sources to Total Nitrous Oxide (NOx) and Particulate Matter (PM10) Emissions from a Container Port
Nationally, the proportion of pollution from commercial ships is growing due to the lack of regulation. This category of pollution is expected to account for one-fifth of all diesel soot generated in 2020, making ships the second-largest source nation- wide.17 Indeed, as Figure 1 shows, marine vessels contribute an average of 34 percent of NOx and 44 percent of PM emissions from ports alone.18 While new trucks are fairly clean compared to other diesel sources, the local trucks that serve container ports tend to be much older than the long-haul truck fleet, and therefore more polluting. Figure 1 alsoshows that diesel trucks are the second-largest source of port emissions today. Locomotives and cargo-handling equipment are also extremely polluting compared to on-road trucks due to their much more relaxed emission standards—in some cases 15 times more polluting. While there is only a limited amount of cargo-handling equipment at ports compared to tens of thousands of trucks that can service a port in a single day, this pollution source on average contributes almost a quarter of the emissions of NOx and PM at ports. Locomotives
are a relatively small contributor to overall port emissions; however, most of the large railyards serving ports from Long Beach to Virginia are significant pollution sources outside of port property, and therefore not included in overall port emissions.
Although cars, power plants, and refineries are all well-known, large sources of pollution, Figure 2 demonstrates that the air pollution from ports rival or exceed these sources. This can be attributed to varying degrees of regulations. Pollution from cars, power plants, and refineries are somewhat controlled, whereas port pollution has continued to grow with almost no regulatory control. The Port of Los Angeles is the
Nitrous Oxide (NOx) and Particulate Matter (PM10) Pollution from Ports Compared to Refineries, Power Plants, and Cars
WATER POLLUTION FROM PORT OPERATIONS
Port operations, including waste from ships that is either dumped directly or leached into water, can cause significant damage to water quality—and subsequently tomarine life and ecosystems and human health. These effects may include bacterial and viral contamination of commercial fish and shellfish, depletion of oxygen in water, and bioaccumulation of certain toxins in fish.20
Primary Threats to Water Quality
Bilge is water collected at the bottom of the hull of a ship-water that is often con- taminated with oil leaking from machinery. Bilge water must be emptied periodically to maintain a ship’s stability and to prevent the accumulation of hazardous vapors. This oily wastewater, combined with other ship wastes such as sewage and waste- water from other onboard uses, is a serious threat to marine life.21
Antifouling additives are often added to the paint used on ships to prevent the growth of barnacles and other marine organisms on ship surfaces. Some of these additives contain tributyltin (TBT), a toxic chemical that can leach into water.22 While toxic antifoulingadditives are slowly being phased out of use, these toxic pollutants persist in the marine environment. Alternatives to TBT are in ample supply.
Stormwater runoff is precipitation that travels across paved surfaces. It can accumulate deposits of air pollution, automotive fluids, sediments, nutrients, pesticides, metals, and other pollutants. In fact, urban stormwater runoff from all sources, including marine ports, is the largest source of impairment in U.S. coastal waters and the second-largest source of water pollution in U.S. estuaries.23 Virtually all of the land at a port terminal is paved, and therefore impervious to water.
When water bodies are overloaded with nitrogen, algae and plankton can rapidly increase in numbers, forming “blooms” which are sometimes called red or brown tides. This process, called eutrophication, has been identified by the National Research Council as the most serious pollution problem facing estuaries in the United States.24
As major sources of NOx, ports are major contributors to eutrophication.
In the year 2000, 8,354 oil spills were reported in U.S. waters, accounting for more than 1.4 million gallons of spilled oil. The majority of these spills occurred in internal and headlands waters, including the harbors and waterways upon which ports
rely.25 A large share of oil contamination is the result of “chronic” pollution from such sources as port runoff, unloading and loading of oil tankers, and the removal of bilge water—resulting in up to three times as much oil contamination as tanker accidents.26 However, large, “catastrophic” spills also have a significant impact.
Dredging is a routine activity of ports to remove sediment thatbuilds up in ship channels from erosion and silt deposition. Dredging also creates new channels and deepens existing ones. Each year, more than 300 million cubic yards of sediment in waterways and harbors are dredged to allow ships to pass through.27 About five
to 10 percent of dredged sediment is contaminated with toxic chemicals, including polychlorinated biphenyls (PCBs), mercury and other heavy metals, polycyclic aromatic hydrocarbons (PAHs), and pesticides—all of which can cause water contamination and complicate sediment disposal.28 Dredging may also increase water turbidity (cloudiness), harm habitat, and disturb or kill threatened and endangered species. It may also risk stirring up and releasing buried contaminants.
These various forms of water pollution cause a broad range of environmental problems, including loss of critical wetlands areas, water sedimentation that harms important habitat (seagrass beds, in particular), collisionsinvolving boats and marine mammals, and marine life exposure to debris, including plastic bags, netting, and plastic pellets.
LAND USE PROBLEMS AT PORTS
The highly industrialized operations at ports are often in close proximity to resi- dential areas, creating nuisances and hazards for nearby communities. Ports have several available options to avoid developing new terminals near residential areas. They can develop property previously used in an industrial capacity, or they can increase efficiency of land use at existing terminals. The land use patterns at U.S. ports suggest much room for efficiency improvements. Of the 10 largest U.S. ports, even those that are most efficient in terms of land use, Long Beach and Houston, are four times less efficient than the Port of Singapore, a model of land-use efficiency.
One positive approach to land use is for ports to focus their expansion efforts on brownfields, or tracts of land that have been developed for industrial purposes, polluted, and then abandoned.29 The potential costs of cleaning up brownfield sites makes them less appealing to companies looking to locate or expand, and as a result, new industrial operations are often sited on pristine, undeveloped “greenfield” land. This often leads to a loss of habitat and wildlife, increases in air and water pollution, and urbanization of open space valuable for its recreational and aesthetic qualities.30
However, developing brownfields offers many advantages to business, communities, and the environment. Businesses benefit from locating on sites near existing transporta- tion infrastructure, and with a utility infrastructure already in place, while cleaning up contamination that poses a dangerto both the community and the environment.31
PORT COMMUNITY RELATIONS
Ports can be very bad neighbors. In addition to the air and water pollution problems they create, they can be loud, ugly, brightly lit at night, and a cause of traffic jams. These problems can go beyond simple annoyance to cause serious negative health effects. For example, noise pollution has been linked to hearing impairment, hypertension
(high blood pressure), sleep deprivation, reduced performance, and even aggressive behavior.32 At ports bordering residential neighborhoods, bright lights at night and the flashing lights of straddle carriers and forklifts can affect nearby residents, dis- rupting biological rhythms and causing stress and annoyance.33,34
Inaddition to the negative effects experienced by people, noise from ship engines may disturb marine mammal hearing and behavior patterns, as well as bird feeding and nesting sites.35,36 Similarly, artificial lights at ports, sometimes burning 24 hours a day, can have negative effects on wildlife, including disorientation, confusion
of biological rhythms that are adapted to a day/night alternation, and a general degradation of habitat quality. This pollution can cause high mortality in animal populations, particularly to birds attracted to brightly lit buildings and towers and that circle these structures until they die of exhaustion or run head on into them.37,38
Ports can also be bad neighbors by ignoring residents of the communities living next door, or making little or no effort to solicit community input into port opera- tional decisions that will directly affect the life of the community and its residents. Many U.S. ports have developed decidedly hostile relations with their neighbors, not just because of the pollution the ports produce, but because they have consistently ignored residents of nearby communities, refusing sometimes even to share critical information about possible effects of port operations.