All I have to say about this is

DUH!!! They really needed to do a study to figure this out? Did anybody actually think that wealthy, white communitites wouldn't have less hazardous waste sites? From the Boston Globe:

Poor areas seen more burdened by waste

The study found that 24 of the 30 communities with the most environmentally hazardous sites have nonwhite populations of 25 percent or more. Areas with minority populations of 25 percent or more also have more chemical pollution and hazardous waste and, as a result, poor and minority residents are more at risk of health problems, the study says.
Charlestown, East Boston, Hyde Park, and South Boston all ranked high for hazardous industries per square mile.
Chinatown, Back Bay, Beacon Hill, and the South End were pooled into one area that made the same list partially due to Big Dig pollution.
''I think that racial discrimination gets played out in a number of different ways, that has people of color concentrated in these areas," said Daniel R. Faber, a Northeastern sociologist who helped write the study. ''As communities become more diverse, there's almost a direct correlation between environmental hazards and the percentage of the community which is nonwhite."