West in 1986 reported that a few miners permanently lived in the mine area. A small group of men, caretakers of the mine, has lived at an altitude of in a galvanized iron hut. One of them reportedly had spent two years there. These are considered to be the highest human inhabitants on Earth. Research performed on Aymara miners of the Aucanquilcha mine indicates that they are fully acclimatized to the altitude, with less hyperventilation and higher hemoglobin than acclimatized people from lower areas. Their families are born and raised at lower altitudes, however.