Authorities released an official reply on Friday to an open letter about rice laced with cadmium in Jiujiang in East China's Jiangxi province. An investigation was made at the scene and at the same time the tainted rice was collected and rendered harmless after treatment, as reported by Beijing Youth Daily.

A public letter issued by a volunteer via social media on Nov 6 said that the cadmium that existed in the paddy near two villagers' homes exceeded the allowed amount in different degrees, as revealed in a third institution's test during the rice harvest near Gangkou Street in Jiujiang.

"Meanwhile the content of cadmium and arsenic from the irrigation water source at the farm and in the bottom of East Lake, a migrant bird habitat, also exceeded limits," the letter added.

Some detailed inspection results showed pollution levels exceeded the threshold of soil pollution, according to the report. The cadmium content in the soil was 0.312 mg/kg, 1.56 times the national standard. Arsenic also reached 7.13 times the soil pollution standard.

A copper sulfide mine nearby that drained sewage for a long term was cited in the letter as the source of the pollution. Established in June 1988, the mine's wastewater had gone through the village to East Lake.

The mine had been ordered to suspend operations on Aug 30, according to the official reply. Third party institutions were hired to investigate the pollution and prepare treatment plans.