but joining us now is jim morris, the senior reporter and editor at the center for public integrity,t in this project. thanks for your time. >> thank you for having me. >> why did you pick the eagleford shale in south texas. why focus on that region when you're look into this issue? >> we picked the eagleford because it's one of the biggest in the world, and yet for some reason, it hasn't become part of the national conversation. people hadn't been paying much 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

jim morris is one of the journalists who worked on it for the center of public ingegrity. welcome to the program. >> thank you. >> a little bit of background. how much drilling of this kind is going on in this south texas area and why did you decide to look at the air quality issue. >> there are about 8,000 wells that have already been drilled in the eagleford shale which 20,000 square miles, another 5,000 or so have been permitted orion line. we chose to look at the eagle ford specifically because it has not been part of the national conversation on fracking. and we looked at air because so much focus has been put understandably on contaminated water that we felt it was time to look at air pollution. >> woodruff: what were your main findings. >> the main findings were that there are all manner of toxic chemicals associated with oil & gas production that appear to be making people sick. benzene which can cause cancer, sulfur dioxide which causes severe lung problems, hydrogen sulfide which can cause a variety of chronic conditions and also it can be lethal in high enough d