Diesel is the fourth-largest source of carbon emissions in Portland and emits a grab bag of pollutants, including soot, that affect low-income communities of color more than wealthy areas farther from freeways and industry.  Those of us living and working in North Portland near the terminals and I5 are experiencing some of the highest rates of lung cancer in the country. 

Diesel pollution in Portland is more than 10 times higher than the state's healthy air benchmark. Diesel particulate is known to cause cancer and many other health problems, and it's a major source of black carbon, which contributes to global warming. But, federal laws limit the city's options for reducing it.

North Portland falls in a census tract with levels of diesel pollution that are likely higher than 70 percent of all others, with a concentration estimated somewhere between 1.13 and 1.38 micrograms per cubic meter (µg/m³).

Diesel levels nearly anywhere within urban areas or near highway intersections are worse than the benchmark used by Oregon health experts, meaning the vast majority of the country's population breathes diesel particulate matter at levels deemed unsafe.