The image above is provided courtesy of Climate Visuals

TL;DR — Ports and logistics operations are major sources of harmful air pollution that affects air quality and climate health both locally and at the global scale — especially as maritime shipping becomes increasingly prominent globally. Diesel emissions from ships are one major source of harmful air pollutants and contribute to the concentrations of criteria pollutants such as particulate matter, nitrogen dioxide, and sulfur dioxide as well as climate pollutants such as black carbon and greenhouse gases. Port-related pollution also poses a threat to environmental justice because of its proximity to near-port communities, which tend to be socioeconomically disadvantaged. By implementing effective air quality monitoring and port emission reduction strategies, we can work to reduce these negative impacts and promote more environmentally friendly global supply chains.

Air quality challenges in ports

Ports, shipping, warehouses, international logistics operations, and components of the global supply chain produce significant amounts of air pollution that harm human and environmental health, making it highly important to understand how to measure and improve air quality at these sites effectively.

Some of the primary sources of air pollution at ports include truck emissions, vehicle idling, ship and rail emissions, and other port equipment. 

The graphic above outlines some major sources of air pollution at ports, including both transportation sources like trucks as well as stationary sources such as power generation. Understanding the wide array of pollution sources linked to port and industrial activities is essential to best leverage air pollution reduction actions. (Image source: US EPA)

Auxiliary engines that are kept running while ships are docked produce harmful air pollutants, including particulate matter, nitrogen dioxide, sulfur dioxide, and carbon dioxide. Traffic and other industrial activity around ports mean that these communities often have worse air quality than surrounding areas, in addition to other issues such as traffic congestion.

Diesel-related air pollution

Air pollution from diesel fuel is also a major source of port-related pollution.

Different types of port equipment — including equipment, some vehicles, and marine vessels — all burn diesel fuel, releasing particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, and air toxics.

Pollution from diesel fuel can also be a significant health and environmental concern for communities that live near ports.

Fortunately, a variety of measures have been put in place to lower diesel pollution, including engine modifications that can be made to reduce the primary types of pollutant emissions, regulations requiring the production of cleaner engines, and other emission control technologies. 

The figure above illustrates different approaches that help to reduce port pollution, from those involving the technology and equipment used to maintenance and operations procedures that contribute to less polluted air. (Image source: US EPA)

Many ports have developed air quality management programs that help to reduce diesel emissions, not only because of their health and environmental impacts through unclean air but also because of the way they impact climate change as a source of greenhouse gas emissions.

However, because diesel equipment lasts a long time, the shift to newer, less polluting equipment can take time.

The duration of use is usually significantly longer for marine vessels than for roadside vehicles. Therefore, these vessels are often powered by relatively old engines which may propagate air pollution. Also, the quality of fuel used for marine vessels is usually not comparable to the quality of fuels used in the automotive sector and therefore, port areas may exhibit a high degree of air pollution.” 

— Mueller et al., 2011

Port-related air pollution in action

The gravity of port pollution’s impacts can be illustrated by the situation at various ports around the U.S., whose impacts affect both the human and environmental health of the surrounding area.

In 2019, the three largest ports in the United States—the Ports of Los Angeles, Long Beach, and New York and New Jersey—emitted over 2.5 million tons of carbon dioxide equivalent (CO2e). This estimate includes emissions from ocean-going vessels at port, harbor craft, cargo handling equipment, locomotives, and heavy-duty vehicles. Other pollutants released from port operations include particulate matter (PM), nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide (CO), and hydrocarbons (HC), all of which are harmful to human health.”

— Environmental and Energy Study Institute

In Southern California, the combined pollution of the Port of Los Angeles and the Port of Long Beach totals 100 tons of smog each day — more than the emissions that the six million cars in this region produce each day.

The region had a brief respite from this air pollution in 2020 when COVID-related disruptions to the supply chain significantly diminished shipping traffic — but this did not last. In 2021, the Port of Los Angeles had a recorded 147% increase in diesel particulate matter and a 136% increase in greenhouse gas emissions as compared to the previous year. The Port of Long Beach had a less dramatic but similarly significant increase in emissions.

The environmental justice impacts of port pollution

In addition to port activities causing harm to overall air quality, poor air at these sites can negatively impact the health of employees at the site and communities who live nearby.

Exposure to poor air quality, especially emissions from diesel engines, can contribute to a variety of health conditions, including:

  • Premature mortality
  • Increased cancer risk
  • Increased respiratory symptoms
  • Increased hospital admissions for heart and lung disease

To learn more about the myriad of ways that air pollution negatively impacts human health, read our blog here.

Near-port communities are often communities of color or low-income communities, and they face higher levels of air pollution from ports. These communities are often overburdened with multiple sources of pollution, from ports to freeways and factories, which negatively impacts their health and can cause respiratory issues, cancer, and premature death.”

— Environmental and Energy Study Institute

Mitigating the impacts of port pollution on air quality and climate health

Considering the vast impacts that port-related air pollution has on overall air quality, climate health, and public health, it is highly important to implement port emission reduction strategies.

Because maritime shipping occurs so widely across the globe — with ships carrying goods stopping in many countries and cities along their route — working to make this system more environmentally friendly means coordinating action at both the global and local levels.

To learn more about the importance of linking local action and global solutions, read our blog here.

The importance of air quality monitoring at ports 

Monitoring air quality around ports and shipping centers is of paramount importance due to the significant environmental and public health implications associated with maritime activities. In addition to safeguarding human health, monitoring air quality around ports aligns with broader sustainability goals for shipping companies themselves as well as international corporations looking to reduce the Scope 3 impact of their supply chain

Identifying and understanding the sources of pollution through air quality monitoring allows for the implementation of targeted measures to reduce emissions, such as the use of cleaner fuels, optimizing shipping routes, and promoting the adoption of environmentally friendly technologies. 

Ultimately, comprehensive air quality monitoring facilitates a more informed and proactive approach to addressing the environmental challenges associated with maritime activities, contributing to the creation of cleaner, healthier, and more sustainable port environments.

Port emission reduction strategies 

In addition to establishing a baseline through the deployment of resilient air quality monitoring networks, a variety of strategies can be implemented to reduce emissions.

Replacing engines that run on fossil fuels such as gasoline or diesel with electric engines — ideally, those that use a renewable source of energy — helps to reduce harmful diesel and greenhouse gas emissions, thereby contributing to both cleaner air and a healthier climate. 

Electric engines have the added benefit of reducing noise pollution in near-port communities, as well as a generally cheaper cost and easier maintenance.

Shore powering — which describes the practice of connecting ships at port to electrical hookups, allowing their engines to be shut off while docked — can reduce air pollution from these ships by up to 98%. When just one container ship is shore-powered, the gain in clean air is equivalent to taking 33,000 cars off the road for one day.

Replacing old trucks is also a highly important part of reducing vehicle and diesel emissions.

At the three largest ports in the United States—the Ports of Los Angeles, Long Beach, and New York and New Jersey—heavy-duty vehicles produced emissions equivalent to over one million tons of carbon dioxide in 2019. Across the country, heavy-duty vehicles at ports are a significant source of greenhouse gas emissions and other pollutants, such as particulate matter and nitrogen oxides, that contribute to the climate crisis and impact the health of near-port communities.”

— Environmental and Energy Study Institute

Many ports have implemented truck replacement programs to replace more polluting vehicles with cleaner ones over time.

Installing solar panels and using other renewable sources of energy generation helps to reduce ports’ reliance on fossil fuels, thereby also cutting down on emissions. After installing solar panels, the Port of Seattle saves over $10,000 in energy costs and reduces carbon dioxide emissions by 2.2 tons each year.

Air quality measurement is the first step to managing port-related air pollution

Interested in measuring air quality for cleaner air, improved physical and mental health, and a healthier climate? Get in touch with our team to learn more about our Sensing-as-a-Service solution for governments, businesses, and community organizations, using our Clarity Node-S monitors and Modules that do not depend on infrastructure like WiFi or power — making them especially resilient in harsh environments like ports.