canser-causing industrial air pollution in the u.s. joining me now is leila eunice, "propublica" reporter and one of the four authors of the report. leila, your investigation shows from the urban sprawl of houston to the river ways of virginia, air pollution from industrial plants is elevating the cancer risk of an estimated quarter of a million americans to a level the federal government considers unacceptable. why is this happening? >> so, rev, the primary reasons concerns the way the agency assesses cumulative risk or the total amount of cancer risk resulting from all of the major sources of toxic air pollution in an area. so when the agency conducts a cancer-risk assessment, they do so by only considering one type of facility or even in some cases one type of equipment at a