Results and analysis on the national key monitoring of endemic arsenism in Jilin Province in 2005 and 2006

Abstract

Objective To explore the present condition of endemic arsenism, the implementation of control measures and the effect of the monitored county (Tongyu County) and the monitoring spot (Baiyintuhai Village) in 2006 and 2007. Methods According to the National Survey Scheme of Endemic Arsenism, the progress of anti-arsenic water in Tongyu, and the management and running of all engineering projects and the arsenic content in water were surveyed. The patients with endemic arsenism in Tongyu were generally surveyed. The arsenic content of the improved drinking water in Tongyu and the arsenic in urine of children aged 8-12 and adults over 18 years of age were determinted. The causes of resident death in the monitoring spot from the year of 2006 and 2007 were investigated. Arsenic content of drinking water and the urine of local residents was examined with Model AFS-930 Double-Channel Atomic Fluorescence Spectrometer. Results There were 30 endemic arsenism areas, 157 areas with high arsenic content and all population of 57 576 in Tongyu. Six areas had improved water till 2006, where 20.0% of water had improved, and six water-improving projects were all running normally, benefiting a population of 1670. Eight high arsenic areas changed water, in a rate of 5.09%. Eight water-improving projects were functioning well, benefiting a population of 4350. Until 2007, 28 areas had improved water in Tongyu, accounting for 93.33%. These 28 projects were well running, covering a population of 7980. One hundred and fouty-eight high arsenic areas had changed water, reaching a rate of 94.27%. One hundred and fouty-eight projects changedg water were running normally, benefiting a population of 46 214. In the surveyed spots, arsenic content was between 0.004 mg/L and 0.005 mg/L in 2006 and between 0.010 mg/L and 0.021 mg/L in 2007, all in the normal range to the time being. The arsenic contents in urine of the children aged 8-12 in the monitoring spots were determinted, averaging at 0.024 mg/L in 15 samples, fluctuating between 0.005 mg/L and 0.048 mg/L in 2006. The average content in urine from adults was 0.019 mg/L in 53 samples, fluctuating between 0.005 mg/L and 0.087 mg/L in 2007. The arsenic contents in urine were all in the normal range in 2006 and 2007. In 2006 14 endemic arsenism patients, all in light symptoms, had been checked out, the morbidity being 6.19%. In 2007, 17 patients who were all in light symptoms were identified in a rate of 6.94%. There was no significant difference of morbidity between the two years(χ2=0.1059, P>0.05). Two patients died, unrelating with drinking high arsenic water in 2006 and 2007. Conclusions The prevention and control measures are well implemented in Tongyu. The water-improving projects are functioning well. The condition of endemic arsenism is slight and hasn't changed so much in these two years. The arsenic contents in urine of children and adults within the normal range, showing that improving water can control the occurrence and the development of endemic arsenism. Key words: Arsenic poisoning; Drinking; Environmental monitoring; Population surveillance