Water Quality and Health Risk Assessment of an Ion-adsorption Type REE Mining Area of the Huangpi River Basin, Northern Ganzhou of China

Water quality security and human health are important to ensure rural revitalization of old liberated areas. The continuous development and utilization of ion-adsorption type REE deposits in northern Ganzhou aggravate trace elements from ores and tailings to the water cycle, thereby endangering the sanitation and safety of drinking water.

To investigate and evaluate health risk and water quality on the watershed scale of rare earth ore concentration area in the Huangpi River Basin.

The contents of manganese, cadmium and other elements were determined by inductively coupled plasma-optical emission spectrometry/mass spectrometry(ICP-OES/MS). By choosing "standards for drinking water quality" (GB 5749—2006) as the evaluation basis, the water quality index (WQI), hazard quotient (HQ), and cancer risk (CR)were adopted to evaluate water quality and human health risks through analyzing 9 indices including Pb and Mn.

NH₃-N and Mn were anomaly indices whether in surface water or groundwater. The average values of NH₃-N were 750μg/L and 4533μg/L in surface water and groundwater, respectively. Index values of Mn were 207μg/L and 4009μg/L in surface water and groundwater, respectively. Arsenic, class I carcinogen published by the World Health Organization, had no abnormality in surface water and groundwater. Moreover, 85.7% of surface water and groundwater was found to be suitable for drinking upon analyzing the WQI values. The HQ average value of NH₃-N was less than 1 in surface water and groundwater so it had no harmful effects on human health. However, the HQ average value of Mn was more than 1, which may be harmful to human health. CR values of As varying from 10^-6 to 10^-4 were also calculated, and the risk of cancer was acceptable.

It is suggested that relevant departments should pay attention to the status of NH₃-N and heavy metal elements in water during the reclamation evaluation of rare earth mines. The research detailed in this paper confirms that the groundwater monitoring system of manganese should be improved.