Many locomotives that travel through our cities and neighborhoods are powered by high-polluting diesel engines that lack pollution controls.

The scope of the problem is centered here, as Chicago remains the busiest rail gateway in the United States and accounts for one-third of the nation's freight rail traffic. Due to the high volume of freight, Chicago's levels of locomotive pollution are greater than any city in the country. In fact, the amount of smog-forming nitrogen oxides (NOx) emitted from locomotives in Chicago is equal to the emissions of more than 25 million cars. To read the report, click here.

Health effects

Diesel exhaust from locomotives contains more than 40 toxic air contaminants, carcinogens, ozone smog-forming compounds and fine particulate matter ("soot"). Exposure to fine particles is known to cause asthma attacks, heart attacks, lung cancer, strokes and even premature death.

In Illinois alone, it is estimated that diesel exhaust triggers more than 20,000 asthma attacks, causes more than 680 heart attacks and leads to approximately 570 premature deaths each year. Although diesel pollution is unhealthy for everyone, children, seniors, occupational workers and people living with lung disease are especially at risk.


  • Cleaner fuels, such as ultra-low sulfur diesel fuel, reduce "soot" pollution.
  • Install anti-idling technology, such as auxiliary power units and stop/start technologies, which reduce pollution and save fuel.
  • Rail companies can reduce soot emissions from their line haul or passenger trains by 50-60 percent simply by meeting current EPA locomotive emission standards. Companies can also clean up their switcher engines by using either Gen-Set or diesel-electric hybrid engines. Gen-Set switcher engines can reduce smog-forming and soot pollution by up to 80 percent and achieve up to a 40 percent reduction in fuel use. To learn about an Illinois-based company that manufactures cleaner Gen-Set engines, click here.
  • Installing exhaust pollution controls, such as diesel particulate filters, can reduce soot pollution by up to 90 percent.

How you can help

  • Call on Metra to clean up their dirty engines.
  • Sign up for E-Advocacy to learn more about our ongoing advocacy efforts and how you can help improve the lung health of your community.

For more information, visit the Air Quality Library.