CATF investigated the exposure to diesel particles during typical commutes in four cities: Austin, Texas; Boston, Massachusetts; New York City; and Columbus, Ohio. In addition, CATF tested the air quality benefits due to emission control retrofits of transit buses in Boston and transit buses and garbage trucks in New York City.

CATF documented diesel particle levels four to eight times higher inside commuter cars, buses, and trains than in the ambient outdoor air in those cities.

Our investigation demonstrated that you may be exposed to high levels of diesel particles—four to eight times the levels in the outdoor air—whether you commute by car, bus, ferry, train, or on foot

—Bruce Hill, Senior Scientist with CATF

By contrast, Hill noted, pollution levels were negligible for commuters in and near vehicles equipped with modern pollution controls or those that run on lower-polluting fuels such as natural gas.

Resources:

• No Escape from Diesel Exhaust