The sparsely inhabited Leh district in the Indian state of Jammu & Kashmir has been one of the least polluted parts of the state. The famous water bodies of this high altitude cold desert, such as Indus River and Pangong Lake, have faced little threat of pollution until recently.

But an enormous increase in tourism to this corner of the Himalayas has started to change this. Last year the region received a record number of tourists, with 277,255 people visiting Ladakh. This is more than double the entire population of Leh district.

The area around Pangong Lake in Ladakh was not popular among Indian tourists until Bollywood blockbusters 3 Idiots and Jab Tak Hai Jan were filmed there in 2009 and 2012. Today, thousands of tourists visit the lake often via the ecologically fragile Khardung La pass, which is over 5,300 metres above sea level. The Pangong lake straddles India and China, over 750 square kilometres, and is one of the largest lakes in the region.