The massive cadmium spill has again highlighted the mainland's widespread metal poisoning troubles and put the pollution problems caused by the rise of a mining centre in the international media spotlight.
The spill, thought to be the worst heavy metal pollution in decades, is believed to have been caused by the illegal dumping of an estimated 20 tonnes of life-threatening cadmium into the Longjiang, a tributary of the Pearl River, by two smelters in the city of Hechi .
Hechi, in northwestern Guangxi, is famed for its economic rise in recent years, which was heavily reliant on the metal refining industry.
The city boasts the mainland's largest tin reserves and is also rich in zinc, lead and indium.
Cadmium is a byproduct of processing the rare metal indium, which is essential for producing liquid crystal display screens and solar panels.
But Hechi's reliance on the energy-intensive and heavily polluting metal refining industry has wreaked havoc on its spectacular scenery.
Compounded by an apparent failure to tackle mining waste and metallurgical slag, lax government management, disregard for environmental standards and the much-criticised local protection of industrial polluters, the industry has turned rivers black and lush mountains barren.
Hechi may yet follow many other mainland areas where industrialisation has been coupled with the emergence of 'cancer villages'.
Leaks of toxic metals such as arsenic, lead and cadmium have been common in Hechi over the past decade, threatening freshwater supplies for hundreds of thousands of people and posing health risks to the Longjiang and the Liu River into which it flows and on which the city of Liuzhou, with a population of 3.7 million, sits.
In October 2008, a chemical spill left at least 450 people in Hechi poisoned with arsenic.
Xinhua says there are at least 41 water-intensive smelters in Hechi, mostly along rivers. Many do not have adequate waste-disposal facilities and have been dumping industrial waste into rivers for years.
Until recently, little was done about tackling the environmental problems, despite repeated promises by local authorities, because of their obsession with development.