青藏铁路格尔木站一名工作人员在列车进站后进行吸污作业（5月26日摄）。自运行之初，青藏铁路就配备全封闭式车体，实现了车内垃圾对外“零排放”。采用大容量真空集污技术的青藏线列车全程只需在3个站点集中排污，除火车上外，各站点产生的污水也要经过严格处理才能排放。被称为“高原净土”的青藏高原是长江、黄河、澜沧江等5大水系的发源地，也是亚洲重要的水源涵养地和气候启动区。青藏铁路通车10年来，一直采用我国业界最严格的环保标准运营。新华社记者 张宏祥 摄
A worker discharge sewage from a train at the Golmud Station of the Qinghai-Tibet railway in Golmud, northwest China's Qinghai Province, May 26, 2016. The 1,956-kilometer-long Qinghai-Tibet railway, the world's highest altitude train line, has been put into service for 10 years. It links Lhasa, capital of southwest China's Tibet Autonomous Region, and Xining, capital of Qinghai Province in northwest China. [Photo: Xinhua]