Friday on WFPL's Byline, our environment reporter Erica Peterson spent some time with NPR reporter Howard Berkes and Chris Hamby with the Center for Public Integrity. They’ve been investigating a serious resurgence in black lung disease in Appalachia in a series of reports and features made public last week.The joint investigation by NPR and the Center for Public Integrity found that federal regulators and the mining industry are failing to protect miners from the excessive toxic coal mine dust that causes black lung, and the disease is now being found in younger miners and evolving to complicated stages more quickly than in the past.There is a wealth of information about the disease and the series at NPR's site. Berkes and Hamby discuss some of the issues and findings with Erica Peterson in this excerpt from Byline.