GENEVA (AFP) — Swiss and Chinese scientists have found that pollution in China's 6,300 kilometre-long (3,915 mile-long) Yangtze river is "enormous" but still reversible, Switzerland's development agency said Friday.
The results of a joint water quality survey of the world's third largest river, which is also considered one of its most polluted, were "less alarming than expected," the Swiss Development and Cooperation agency (SDC) said in a statement.
"The ecosystem of the Yangtze can be saved if China intensifies its activities in water protection now," said survey organiser August Pfluger.
The scientists urged Chinese authorities to take protective measures similar to those taken in Europe in recent years, especially with the prospect of further pressure on the river from China's booming economy.
Apart from industry, about one-seventh of the world's population -- 400 million people -- who live along the Yangtze's banks pour 25 billion tonnes of waste into the river every year, the study said.
Agriculture is another main source of pollution. An "excessive amount" of mineral fertilizers ending up in the river have doubled its nitrogen concentrations in 20 years, according to the scientists.
Yet "the water quality of the Yangtze is comparable to that of other large rivers in the world," said geochemist Beat Mueller, the former Swiss head of the joint expedition.
And toxic heavy metal concentrations are two to eight times less than those found 30 years ago in Europe's River Rhine -- which notably crosses major industrial regions in Germany, The Netherlands and Switzerland, the SDC said
Still, the relatively low concentrations of heavy metals are mainly due to the enormous flow of water, which helps to dilute them and sweep pollution out to sea.
Each day, 1,500 tonnes of nitrogen and 4.6 tonnes of arsenic wash up along the Chinese coast, feeding the growth of blue-green algae and starving coastal waters of life-supporting oxygen, the SDC said.
That pollution also finds its way into fish eaten in Chinese homes, it said.
Presided by the Chinese Ministry of Agriculture, the Yangtze expedition brought together for several years researchers from the Swiss Federal Institute of Aquatic Science and Technology and the Wuhan Institute of Hydrobiology.
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