Mining began with clearing the ground of vegetation and debris. Newer street sweepers are capable of collecting small particles of debris. Roads were blocked with road debris or the surfaces broken. Some of the debris was contaminated with plutonium. An obstruction can be any type of rough surface capable of snagging debris. NDRF also retrieved 27 dead bodies trapped under debris. Removal of the debris and underbrush had begun. Most injuries were scrapes and bruises caused by flying debris and glass. Other threats include ingestion of marine debris, ocean noise, and chemical pollution. Nests are frequently lined with various materials, including twigs, grass, fur, debris and greenery. Cleanup of space debris was also proposed. Most events have been ground fires that serve to clear forest debris. This law is revised from previous legislation, which focused on removing plastic marine debris. The report called for international regulations limiting debris and research of disposal methods. Satellites are believed to have been destroyed by micrometeorites and (small) orbital debris (MMOD).