Health risk assessment of phreatic water based on triangular fuzzy theory in Yinchuan plain.

Groundwater quality relating closely to human health has become a great concern to the whole society, especially in heavily polluted areas. Yinchuan Plain, located in the arid and semi-arid region of Northwestern China, where people rely heavily on groundwater resource. However, due to the improper groundwater exploitation and negative effect of human activities in recent years, groundwater quality in Yinchuan plain become deteriorated. For the sustainable utilization and protection of groundwater resources, health risk assessment (HRA) of phreatic water is conducted in this paper. On the basis of model recommended by EPA, triangular fuzzy number is applied to establish risk assessment model for health risk assessment of adults and children in wet and dry seasons, respectively. Results of HRA indicate that carcinogenic risk of arsenic is highest among the risk from components in phreatic water, and the highest risk from arsenic to adults and children in wet and dry season are 6.48 × 10-6a-1 and 9.56 × 10-6a-1, 1.08 × 10-5a-1 and 1.59 × 10-5a-1, respectively. This study also states that in Yinchuan Plain carcinogenic risk from drinking groundwater can be 3-4 times magnitude higher than the noncarcinogenic risk. Also it is found that the health risk to children is as 1.5-2 times as to adults, while the uncertainties of adults' health risk are higher than that of children.