Clearing the Air – Why Shipping Pollution is a Public Health Issue

Washington’s bustling ports connect our state to global trade, but they also generate staggering amounts of pollution that harm public health—especially for communities living near ports, shipping lanes, and freight corridors. Maritime vessels rely on some of the dirtiest fossil fuels available, producing particulate matter (PM2.5), nitrogen oxides (NOx), sulfur oxides (SOx), and volatile organic compounds (VOCs)—pollutants that are well-documented drivers of respiratory disease, cardiovascular dysfunction, and premature mortality.

A growing body of medical literature links port and shipping emissions to increased emergency room visits, higher rates of asthma, chronic obstructive pulmonary disease (COPD), stroke, and ischemic heart disease. A 2018 study published in the International Journal of Environmental Research and Public Health found that communities near high-traffic ports experience significantly elevated exposure to PM2.5, leading to heightened inflammation, oxidative stress, and endothelial dysfunction—all precursors to cardiovascular disease. Additionally, exposure to SOx emissions leads to the formation of secondary fine particulates (sulfate aerosols), which penetrate deep into lung tissue, causing chronic respiratory irritation and reduced lung function, particularly in children and older adults.

The environmental justice implications of this issue are severe. In Washington, the communities surrounding ports—such as those near Seattle’s Harbor Island and Tacoma’s industrial waterfront—have some of the highest rates of asthma, cardiovascular disease, and preterm births in the state, according to state health department data. These residents, disproportionately from low-income and historically marginalized backgrounds, are subject to pollution levels that far exceed EPA-recommended safety thresholds.

This session, Washington Physicians for Social Responsibility (WPSR) is advocating for two critical bills to curb the health harms of shipping pollution:

HB 1689: Cutting Ship Emissions at the Dock with Shore Power

While docked at port, large cargo and cruise ships continue burning heavy fuel oil to power their onboard systems, releasing a constant stream of diesel exhaust and ultrafine particulate matter directly into surrounding communities. HB 1689 would require ships to connect to shore power instead, allowing them to draw clean electricity rather than combusting fossil fuels.

The health benefits of shore power are profound. A 2021 study in Environmental Science & Technology found that shore power infrastructure reduces NOx emissions by up to 98% and PM2.5 emissions by 90%. NOx, a precursor to ground-level ozone, is a major contributor to asthma exacerbations and chronic lung disease, while PM2.5 is linked to increased rates of lung cancer and atherosclerosis.

Eliminating these emissions at the source is a direct investment in the health of Washington’s portside communities.

HB 1652 / SB 5519: Phasing Out "Scrubber" Pollution and Transitioning to Cleaner Fuels

Many ships continue to burn high-sulfur bunker fuel while using exhaust gas cleaning systems—commonly known as “scrubbers”—to wash pollutants out of their emissions and discharge them into the ocean. This practice allows ships to skirt cleaner fuel requirements while still producing massive amounts of airborne sulfates, heavy metals, and carcinogenic polycyclic aromatic hydrocarbons (PAHs).

HB 1652/SB 5519 would phase out these outdated scrubber systems and require ships to transition to cleaner fuels, dramatically reducing emissions of toxic air pollutants. Research has shown that reducing emissions from shipping prevents thousands of premature deaths each year, cutting global mortality rates related to air pollution by as much as 34%. Additionally, cleaner fuels decrease ambient SOx levels, reducing the formation of acid rain, which degrades both air and water quality and has been linked to increased hospitalizations for respiratory distress.

As physicians and health professionals, we have a duty to advocate for policies that protect public health and prevent disease at the source. The evidence is clear: shipping emissions are a major and preventable contributor to respiratory and cardiovascular disease in Washington’s most vulnerable populations. By enacting HB 1689 and HB 1652/SB 5519, Washington can significantly reduce disease burden, prevent premature deaths, and move toward a healthier, cleaner future.