Pollution in China: thallium leak in Yangtze River linked to zinc smelter
- Pollution was detected at a monitoring station at the intersection of two tributaries of Asia’s longest river
- Chengzhou Zinc Smelter in Cheng county, Gansu province ordered to suspend operations pending a full inquiry
The alarm was raised when environmental officials in Hanzhong, a downstream city in Shaanxi province, recorded unsafe levels of thallium in a reservoir fed by a tributary of the Yangtze.
Following an investigation, Chengzhou Zinc Smelter in Cheng county, Gansu province was identified as the likely culprit, according to a statement released by the county government on Friday.
Officials from the environment ministry were dispatched to Gansu on Tuesday to investigate the matter further, while local authorities are checking to ensure no other industrial facilities are responsible for the leak.
In the meantime, the company has been ordered to suspend production and halt all discharges of waste water.
Thallium is found in several ores but it is mainly obtained as a by-product of copper, zinc and lead refining. Thallium poisoning can cause vomiting, diarrhoea, damage to the nervous system and vital organs, and even death.
According to the Hanzhong environmental report, on Tuesday, the thallium concentration recorded at a monitoring station on the intersection of Qingni and Jialing rivers, both of which are tributaries of the Yangtze, was 0.22 micrograms per litre, or more than twice the permitted level in China.