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Objective:To understand all causes mortality and cancer mortality of residents in drinking-water-borne endemic arsenism areas 10 to 16 years after water-improvement, and to evaluate the effects of water-improvement on prevention and treatment of the long-term harm of arsenic poisoning.Methods:In April 2020, in drinking-water-borne endemic arsenism areas of Ying County and Shanyin County, Shanxi Province, the diseased villages where water-improvement was carried out in 2003 were selected, and the permanent residents of the survey sites were selected as arsenic-exposure group. The residents in non-diseased villages were selected as control group. All causes and cancer deaths from 2013 to 2019 of the two groups were investigated and analyzed.Results:In arsenic-exposure group, the range of arsenic concentration in drinking water before water-improvement was 0.060 to 0.345 mg/L, and that after water-improvement was 0.000 17 to 0.003 60 mg/L. During the 7 years, a total of 94 128 person years were investigated in arsenic-exposure group and 102 086 person years in control group. There were 828 deaths from all causes in arsenic-exposure group, with a crude mortality rate of all causes of 8.80‰ and a standardized mortality rate of 9.16‰. There were 637 deaths from all causes in control group, with a crude mortality rate of all causes of 6.24‰ and a standardized mortality rate of 6.91‰. The crude mortality rate of all causes in arsenic-exposure group was higher than that in control group (χ 2 = 43.20, P < 0.01). Totally 218 deaths from cancer were reported in arsenic-exposure group, with a cancer crude mortality rate of 231.60/100 000 and a standardized mortality rate of 231.67/100 000. Totally 164 deaths from cancer were reported in control group, with a cancer crude mortality rate of 160.65/100 000 and a standardized mortality rate of 175.97/100 000. The cancer crude mortality rate in arsenic-exposure group was higher than that in control group (χ 2 = 12.69, P < 0.01). The median age of cancer deaths in the two groups was 72.0 and 68.5 years, respectively, and the difference was not statistically significant ( P > 0.05). The cancer crude mortality rate among males in arsenic-exposure group was 317.16/100 000, which was higher than that of males in control group (198.91/100 000, χ 2 = 14.21, P < 0.01), but there was no difference between females in the two groups (134.10/100 000 vs 118.03/100 000, P > 0.05). The highest cancer crude mortality rate in arsenic-exposure group and control group was lung cancer, which were 115.80/100 000 and 69.55/100 000, respectively. The crude mortality rates of lung cancer, stomach cancer and bladder cancer in arsenic-exposure group were higher than those in control group (χ 2 = 11.43, 4.33, 5.05, P < 0.01 or < 0.05), while the crude mortality rates of other cancers were not significantly different between the two groups ( P > 0.05). Conclusions:Simply taking water-improvement measure can't block the long-term health burdens of arsenic exposure, especially for carcinogenic effect. Health follow-up management and disease prevention measures in arsenic-exposed areas will be needed for decades after exposure cessation.
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Objective:To master the changing trend of drinking-water-borne endemic arsenic poisoning in Shanxi Province and the implementation of prevention and control measures, to evaluate the progress of elimination target, and to provide objective basis for the implementation of refined management.Methods:In 2018, according to the mid-term evaluation plan of the "Thirteenth Five-Year Plan for National Endemic Disease Control" and the requirements of the "Measures for Elimination Control and Evaluation of Key Endemic Diseases", in 157 disease affected villages or high arsenic villages of 16 counties (cities, districts) in the province, taking the administrative village as the unit, a census of all permanent residents was conducted to investigate the condition of current patients and find out the new cases of arsenic poisoning; the implementation of water improvement measures and the operation of water improvement project were investigated; one tap water sample was collected from each administrative village to detect the arsenic content in the water; and the elimination of arsenic poisoning was evaluated.Results:A total of 1 221 cases of drinking-water-borne endemic arsenic poisoning were investigated in the whole province, including 982 mild cases, 190 moderate cases and 49 severe cases, accounting for 80.43%, 15.56% and 4.01%, respectively; all the 1 221 cases were monitored and registered before 2011, no new cases were found. In the 157 investigated villages, the rate of water improvement was 94.90% (149/157), the average content of arsenic in water of village with water improvement was 0.022 3 mg/L, ranging from 0.000 5 to 0.193 9 mg/L; the qualified rate of water arsenic after water improvement was 83.89% (125/149), and the normal operation rate of water improvement project was 82.55% (123/149). Ten counties (cities, districts) had reached the elimination standard, and six counties (cities) had not reached the elimination standard.Conclusions:The prevention and control effect of control measures on drinking-water-borne endemic arsenic poisoning in Shanxi Province is remarkable, and there is no new case for many years. In the future, efforts should be made to improve water supply, carry out one village one policy refined management, ensure that all disease affected villages or high arsenic villages meet the national elimination standards, and achieve the goal of the special three-year program for prevention and control of endemic diseases.
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Objective To evaluate the effect of water improvement projects on drinking-water-borne endemic arsenism in Shanxi Province,to work out and refine sustainable prevention and control strategies.Methods The operating situation of water-improvement projects was investigated and monitored,and the arsenic content in drinking water was determined in drinking-water-borne arseniasis areas,which including 14 monitored sites in 5 countries from 2012 to 2017.The condition of arsenic poisoning in the resident population of the monitored sites was investigated and the arsenic content in the urine of patients was determined.Results Totally 14 monitored sites were already finished water improvement,the rate of water-improvement was 100％.Totally 11 water-improvement projects were monitored,including 7 small-scale water-improvement projects and 4 large-scale water-improvement projects,which all qualified and operated normally from 2012 to 2015.In 2016,one water-improvement project was found with excessive level (＞ 0.01 mg/L) of arsenic in drinking water in Shanyin County,and the other 10 water-improvement projects' arsenic contents were qualified.In 2017,two unqualified large-scale water-improvement projects had water arsenic content over (＞ 0.01 mg/L) in Shanyin County and Ying County,respectively.And the other 9 water-improvement projects were qualified.The detection rates of arsenic poisoning from 2012 to 2017 were 1.36％ (104/7 641),1.57％ (123/7 832),1.61％ (123/7 621),1.53％ (120/7 857),1.28％ (102/7 963) and 1.56％ (124/7 958),respectively,and the differences were not statistically significant (x2 =4.979 9,P ＞0.05).Most patients with arsenic poisoning were mild to moderate patients,accounted for 82.61％ (575/696) and no new case was detected.Conclusions Arsenic poisoning in drinking-water-borne arseniasis areas in Shanxi Province has been controlled.Natural operation of water-improvement projects has kept water arsenic levels normal.Water arsenic content has exceeded the standard in some of the water-improvement projects.The key point of next stage is strengthen the management of water improvement projects in prevention and treatment of drinking-water type endemic arsenism.