Analysis of cancer mortality in drinking-water-borne endemic arsenism areas 10 to 16 years after water-improvement / 中华地方病学杂志

ABSTRACT

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.