High in the Tienshan mountains in the westernmost region of China, pristine snowfields feed the streams that fill a famous local beauty spot known as Heavenly Lake. The crystal waters inspire even more column inches of enthusiastic brochure-ese than they might otherwise, for such enthusiasm is impossible across most of China.

The industrial revolution that has lifted 400 million Chinese, perhaps more, out of poverty in less than a generation, turning their country into the world’s dominant manufacturer and newest economic giant, has also despoiled its environment almost beyond recognition. As the water table in the north of the country drops by a metre a year, 300 leading cities are running short of water. Hundreds more choke under clouds of airborne particulates, with particularly damaging effects on children and the elderly. Every main river is heavily polluted, some to the point that their water is useless even for irrigation.

China’s vast size means its environmental challenges are necessarily shared by its neighbours. This has never been clearer than in the past week, when Beijing belatedly acknowledged that an explosion at a petrochemical plant in Jilin province had released 100 tons of carcinogenic benzene into the Songhua River. The toxin has since formed a 50-mile slick heading slowly north through the city of Harbin, where more than three million people have been without mains water since Tuesday, towards the Russian Far East.

A separate explosion yesterday at a chemical plant in the south west caused the evacuation of 10,000 people — and further clarified China’s responsibilities to its citizens and the wider world. Beijing must lend substance to Premier Hu Jintao’s recent promises of an environmentally friendly China (and a “Green” Olympic Games in 2008) by committing more resources to industrial clean-up operations and accident prevention, even at the price of slower economic growth. It must speed up the reporting of accidents, by persuading local and regional officials they have nothing to fear as purveyors of bad news. And it must break the lethal habit of obfuscating when passing on such news. The Jilin explosion took place on November 13, but in a replay of official stonewalling over the Sars outbreak two years ago and avian flu last month, no full statement was issued for ten days. This was quicker than might have been expected a decade ago. But, with international relations as well as thousands of lives at stake, it was still ten days too long.

Nor can the developed world stand idly by. Western governments and businesses have profited from low Chinese labour costs as much as China has from their investment. They must now invest for sustainable Chinese growth, not growth at any cost, backing non-governmental groups where appropriate and providing Chinese access to cutting-edge environmental technologies. Mr Hu is fond of noting that the West’s industrialisation was a dirty process. He does not have to repeat all of history ’s mistakes.