Methodology (Dirty Secret)

The Chicago Reporter examined particulate matter emissions and their potential effects at the Chicago area’s 15 biggest “intermodal” rail yards—where goods are transferred between trains and trucks—by analyzing statistics from two studies. The data on “lifts”—the measure of how many times a cargo container is moved—in 2006 were obtained from a report by the Chicago Metropolitan Agency for Planning. They were compared with emission figures and corresponding cancer-risk assessments for California yards studied by the California Air Resources Board.

The resulting findings for Chicago yards are rough estimates, as numerous variables, such as wind patterns and specific types of equipment used, play into the amount
and dispersion of particulate matter emitted per lift in the surrounding community.
But it is reasonable to expect that emissions from Chicago rail yards would present cancer risks for nearby residents as found in California, said Andrea Hricko, associate professor at the University of Southern California’s Keck School of Medicine.

Hricko pointed out that, if anything, this method might underestimate the emissions in Chicago since California has been more progressive in implementing locomotive emission reductions.

Read the responses from rail companies:
From CSX Corporation
From Burlington Northern Santa Fe Railway