attention to it beyond south texas. so that's why we looked at it. >> there's been a lot of concerns about fracking having potential effect on ground water. we've been reporting just recently a spike in quakes which may be caused because of the injection of water in the process. how did you know that quality of air is linked to that region of the country? why air pollution? >> we started to hear in the last year or two complaints from people about bad air and about illnesses they blame on the bad air. but if you look at complaints, a lot of people had to do with air. rotten egg odors, people who were nausea, nosebleeds, severe asthma attacks. it was clear to us early on, those were air problems. those were all air related. i think that sort of helped steer us in that direction. >> your report today has landed with a big splash. texas state regulators pushed