puerton maldonado is also a place in transition - while many of its roads are still dirt paths - the new interoceanic highway has opened the area up to the wider world. >> people come from all over the country to work the gold fields here in madre de dios. >> luis fernandez directs the carnegie amazon mercury ecosystem project. he's been studying gold mining's toxic legacy in the amazon since 2000. so now, miners have better access to the remote forest, they can get their equipment there, everything's easier because of that highway. >> everything's easier, it's essentially part of the perfect storm that is madre de dios. so not only do you have a brand new highway that makes transport easier, you have record high gold prices and the preexisting condition of extreme poverty. >> tell me about this illegal gold mining. what is the process? >> we're really on the edge between the amazon and the andes, and erosion over millions of years have worn down the rocks of the andes, which are gold rich, and all that sediment has washed down the rivers. >> next stop - a mining area near la pampa.