Investigation of Groundwater Contamination and Health Implications in a Typical Semiarid Basin of North China

Groundwater chemistry and its potential health risks are as important as water availability in arid and semiarid regions. This study was conducted to determine the contamination and associated health threats to various populations in a semiarid basin of north China. A total of 78 groundwater samples were collected from the shallow unconfined aquifers. The results showed that the phreatic water was slightly alkaline, hard fresh water with ions in the order of Ca2+ > Na++K+ > Mg2+ and HCO3- > SO42- > Cl-. Four hydrochemical elements, NO3-, F-, Mn and Zn, exceeded the permissible limits. NO3- and F- contaminants may pose health risks to local residents, while the risks of Mn and Zn are negligible. Dermal exposure is safe for all populations, while the oral pathway is not. Minors (i.e., infants and children) are susceptible to both NO3- and F- contaminants, and adults only to NO3-. The susceptibility of various populations is in the order of infants > children > adult males > adult females. Anthropogenic activities are responsible for the elevated levels of NO3-, Zn, Total dissolved solids (TDS), while F- and Mn are from geogenic sources. Thus, differential water supplies, strict control of waste, and rational irrigation practices are encouraged in the basin.