Seven chemical plant executives in China were detained in a probe over the industrial waste discharges containing high levels of cadmium, Chinese officials said Monday. Feng Zhennian, a regional environmental protection department official, said the executives work for plants in the Guangxi Zhuang region, including Jinchengjiang Hongquan Lithopone Material Co. Ltd. in Hechi, Xinhua reported.
Cadmium pollutants, first detected in Longjiang River near the Lalang reservoir on Jan 15, were found to be 80 times higher than the official limit of 0.005 milligrams per liter. Neutralizers made from dissolved aluminum chloride were used to dissolve the contaminants at six locations along the river.
Feng said the cadmium concentration at Lalang reservoir has returned to normal and officials were working to protect drinking water supplies for the 1.5 million residents of the city of Liujiang as the pollution moves downstream.
More than 200 surveillance workers are monitoring water quality at 20 testing stations set up along a 124 mile stretch of the river, Feng said.