The latest report of the Sagarmatha Pollution Control Committee has calculated that on an average a mountaineer left behind 65 kg of burnable trash in the Everest region in 2013.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/mountaineers-share-littering-everest-rise
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/himalayan-times-nepal
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/solid-waste
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/himalaya
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/garbage
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/nepal
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/waste-management
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/plastics
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mountaineering
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mountain-ecosystems
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/south-asia