China's heavy industries have tipped so much waste into the river that enormous stretches of it, amounting to over a third of its entire length, cannot be used at all anymore, either for drinking, fishing, farming or even in factories, according to criteria used by the United Nations Environmental Programme.
It's the source of life but it's also the cause of a lot of unnecessary death. In places where clean water isn't available, water-related diseases like cholera cause massive diarrhea, dehydration, and thousands of deaths each day. Affordable water-treatment solutions exist.