Save for a few floating leaves and a tinge of peat, this icy cold water on a mountainside in the Himalayas is probably as pure as you’re likely to find it. Or so I thought. Above the villages you’d expect it to be untouched by humans apart from the occasional trekker or farmer. But then there is all the carbon pollution in our atmosphere, so evident in the valley of Kathmandu. And the recent, and not so recent, media about Everest and man’s attempt to conquer the mountain regardless of the ‘cost’ to other people or the environment. Now, when I look at that clear water it makes we wonder.