Level and Influencing Factors of Iron and Manganese in Drinking Water in Inner Mongolia, China, 2015—2019

Objective To investigate the level of iron and manganese in drinking water in Inner Mongolia Autonomous Region, China, and discuss the factors affecting the content of iron and manganese in drinking water, and to provide a scientific basis for the reform of drinking water and the safety of drinking water.

Methods From 2015 to 2019, the drinking water quality of urban and rural areas in Inner Mongolia was continuously tested, the changes in iron and manganese indices were observed, and the iron and manganese pollution in drinking water was evaluated and analyzed.

Results The qualified rates of iron and manganese content in Inner Mongolia were significantly different among the five years (χ² were 60.00 and 66.55, respectively, P < 0.01), and showed an overall increasing trend from 2015 to 2019 (χ² were 48.90 and 24.55, respectively, P < 0.01). The qualified rates of iron and manganese content were significantly higher in the central and western region than in the eastern region of Inner Mongolia, and were significantly higher in wet season than in dry season. The drinking water from underground water sources had a significantly lower qualified rate of iron content than that from surface water sources. The drinking water in Inner Mongolia was mainly from the centralized water supply, and the qualified rate of manganese content in drinking water from the centralized water supply was significantly higher than that in drinking water from the decentralized water supply.

Conclusion From 2015 to 2019, the qualified rates of iron and manganese content in drinking water in Inner Mongolia were on the rise, and they varied among different water sources, different water periods, and different water supply methods.