Abstract
This article took fluoride in shallow groundwater of a township in southwestern China as the research object. Fifty sampling points were set up in the studied area. The fluoride was tested by the ion-selective electrode method. The health risk model recommended by the United States Environmental Protection Agency was used. Based on the Chinese population, human health risk assessment was performed for fluoride in shallow groundwater in the studied area, and the Kriging interpolation method was used to simulate the spatial distribution of fluoride concentration in the area. The research showed the following. (1) The concentration of fluoride in the shallow groundwater samples in the studied area was 0.06–0.78 mg/L, with an average value of 0.35 mg/L, which was in line with the limit value (1.00 mg/L) in the standards for drinking water quality (GB 5749–2006), but its maximum value was 0.78 mg/L, which was 1.86 times of the background value. (2) The average hazard index of children and adults were 0.27 and 0.15, respectively, which were less than 1, and the risk was at an acceptable level; the noncarcinogenic risk of children was 1.8 times that of adults; the average values of total risk quotient for groundwater fluoride intake by children and adults were 0.27 and 0.15, respectively, and 1.19E-03 and 7.26E-04 by skin, respectively. This indicated that of the two routes, oral intake was the main route of exposure to fluoride. The noncarcinogenic risk values of fluoride in rural and urban areas were similar, and both were less than 1. (3) The high-value areas of fluoride were mainly concentrated in the southeast of the area, which was mainly affected by the superposition of natural factors and industrial park sewage discharge. Through human health risk assessment and spatial distribution of fluoride in regional groundwater, it can provide a theoretical basis for regional groundwater pollution prevention.
Spatial distribution and human health risk assessment of mercury in street dust resulting from various land-use in Ahvaz, Iran
