Beijing, Jan 21 (IANS) High levels of a cancer-causing heavy metal and arsenic have been discovered in a river and reservoir in southern China.

Despite efforts to dilute the pollution, carcinogenic cadmium still remained at three times the permitted levels in the reservoir at the Lalang Hydroelectric Dam on Longjiang river Thursday afternoon, the Shanghai Daily reported Saturday.

But arsenic content has fallen to safe levels since the water was diluted, reported Xinhua.

Authorities in Yizhou city were alerted Jan 15 when fish kept in cages in the reservoir died.

Residents have been warned not to drink water from the river and wells were being dug to ensure safe drinking water, Xinhua said.

Cadmium is a key component in battery production, coatings, electroplating and toys. Exposure can result in fever, pneumonia, kidney failure and cancer.