Spatial and temporal variability of fluoride concentrations in groundwater resources of Larestan and Gerash regions in Iran from 2003 to 2010

Abstract

There is discrepancy about intervals of fluoride monitoring in groundwater resources by Iranian authorities. Spatial and temporal variability of fluoride in groundwater resources of Larestan and Gerash regions in Iran were analyzed from 2003 to 2010 using a geospatial information system and the Mann-Kendall trend test. The mean concentrations of fluoride for the 8-year period in the eight cities and 31 villages were 1.6 and 2.0 mg/l, respectively; the maximum values were 2.4 and 3.8 mg/l, respectively. Spatial, temporal, and spatiotemporal variability of fluoride in overall groundwater resources were relatively constant over the years. However, results of the Mann-Kendall trend test revealed a monotonic trend in the time series of one city and 11 villages for the 8-year period. Specifically, one city and three villages showed positive significant Kendall's Tau values, suggesting an upward trend in fluoride concentrations over the 8-year period. In contrast, seven villages displayed negative significant Kendall's Tau values, arguing for a downward trend in fluoride concentrations over the years. From 2003 to 2010, approximately 52 % of the Larestan and Gerash areas have had fluoride concentrations above the maximum permissible Iranian drinking water standard fluoride level (1.4 mg/l), and about 116,000 people were exposed to such excess amounts. Therefore, our study supports for a close monitoring of fluoride concentrations from health authorities in monthly intervals, especially in villages and cities that showed positive trend in fluoride concentrations. Moreover, we recommend simultaneous implementation of cost-effective protective measures or interventions until a standard fluoride level is achieved.

Temporal and spatial variation of chemical parameter concentration in drinking water resources of Bandar-e Gaz City using Geographic Information System

“…Amouei found that the concentra- tion of fluoride in rural areas of Khaf was 0.11 to 3.59 mg/l. He reported that the fluoride concentration in 31% of the samples was less than the standard, 4% was above the standard and 64% were within standard range [22].…”

“…Amini assessed the mean concentrations of fluoride for the 8-y period in the study area were 1.6 and 2.0 mg/l, respectively and Spatial, temporal, and spatiotemporal variability of fluoride in overall groundwater resources were relatively constant over the years [22].…”

Data on assessing fluoride risk in bottled waters in Iran

“…Seventy one samples of different brands of bottled waters were chosen randomly, and then the fluoride concentration of water samples was determined by Ion Chromatography No. 4110 based on the method mentioned in the book of standard methods for water and wastewater experiments [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] .…”

Data on trend changes of drinking groundwater resources quality in Sabzevar city (A case study)

“…In this study, 805 samples were analyzed by descriptive and analytical statistics (correlation coefficients) in 10 years ( Table 3 ). The important major cations and anions in water samples were analyzed following a standard method (APHA 2008) [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] .…”