The survey of arsenic pollution in Yangzonghai Lake and its influence to the Yangzong River, the water source, the drinking water and local food in Yangzong Town of Yunnan Province

Abstract

Objective To understand status of arsenic pollution in Yangzonghai Lake and its influence to the Yangzong River,the drinking water source and local food and to provide a scientific basis for arsenic pollution control and drinking water and food safety.Methods From 2008 to 2010,the methods of silver diethyl dithiocarbamate spectrophotometric and silver salt spectrophotometry were used to monitor arsenic level in Yangzonghai Lake water,spring water,river water,water source,drinking water and locally produced food,respectively.Results From 2008 to 2010,the average arsenic concentrations of Yangzonghai Lake were 0.12,0.10,0.03 mg/L,and the No.3 spring water were 23.92,2.41,0.35 mg/L,down 16.67％ and 89.92％ over the previous year from 2009 to 2008,and 70.00％,75.00％ and 85.48％,98.54％ over the previous year from 2010 to 2009 and 2010 to 2008,respectively,and showed a downward trend year by year.A spring water about 100 m south of the Big Dipper pumping station into the Yangzonghai Lake and the Yangzong River was not contaminated by arsenic.In Yangzong Town,the arsenic concentration of 268 drinking water samples met Drinking Water Health Standards (GB 5749-2006,＜ 0.05 mg/L).Among 78 samples monitored of the locally produced food in Yangzong Town,77 passed,with a passing rate of 98.72％.Conclusions Arsenic contamination of the Yangzonghai Lake has been effectively controlled.Arsenic pollution does not have a greater influence on drinking water and food safety in Yangzong Town,and arsenic in sediments or bottom mud remains uncertain in the Yangzonghai Lake.More measures and integrated management should be taken to strengthen the monitoring of arsenic pollution in the Yangzonghai Lake. Key words: Arsenic; Drinking; Food; Data collection