To understand the epidemic situation and control effect of drinking-water type endemic arsenism in Inner Mongolia Autonomous Region from 2009 to 2018, and provide a basis for further development and improvement of prevention and control strategies.

In 2009-2018, 38 diseased villages were selected from 8 cities in Inner Mongolia Autonomous Region as fixed monitoring sites to investigate the water improvement situation of the village and the operation of the water improvement project, and to detect the arsenic content of the water; physical examinations were carried out on all the resident populations who were exposed or previously exposed to high levels of arsenic water in the monitoring villages, and the changes in the condition of arsenic poisoning patients were observed; 30 adult urine samples were collected from each monitoring village to detect urinary arsenic levels.

The water improvement rate of the 38 monitoring villages increased from 84.21% (32/38) in 2009 to 100.00% (38/38) in 2013, and continued to maintain; the normal operation rate of water improvement project increased from 64.29% (9/14) in 2009 to 100.00% (18/18) in 2016, and continued to maintain; the qualified rate of water arsenic content of water improvement project increased from 64.29% (9/14) in 2009 to 88.89% (16/18) in 2018; the proportion of qualified project covered population increased from 47.79% (4 846/10 140) in 2009 to 84.35% (5 370/6 366) in 2018. In 2009-2018 the detection rate of arsenic poisoning in the water arsenic content qualified village was 9.17% (3 968/43 276), and the detection rate in the unchanged water and water arsenic exceeded villages was 7.48% (805/10 759); there was no new case for ten consecutive years. There were significant differences in urinary arsenic levels of the water arsenic content qualified villages, the unchanged water and water arsenic exceeded villages between different years (H=424.04, 100.35, P < 0.05); the urinary arsenic level of water arsenic content qualified villagers was lower than that of the unchanged water and water arsenic exceeded villages in the same year (P < 0.05).

During the 10-year monitoring period, the prevalence of arsenic poisoning has been effectively controlled. The water improvement rate and the normal operation rate of the project remain in good condition, but the qualified rate of water arsenic still should to be improved.

Arsenic poisoning; Drinking water; Urine; Monitoring