Fluoride in Iranian Drinking Water Resources: a Systematic Review, Meta-analysis and Non-carcinogenic Risk Assessment

A systematic review, meta-analysis, and non-carcinogenic risk considering fluoride content of drinking water resources of 31 provinces of Iran among some international databases such as Science Direct, Scopus, PubMed, and national databases including SID and Irandoc (2011 to July 2017) were conducted. In this context, 10 articles (40 studies) with 1706 samples were included in meta-analyses and risk assessment studies. The pooled concentration of fluoride in the cold, mild, and warm weather provinces were calculated as 0.39 mg/L (95% CI 0.32–0.48 mg/L), 0.52 (95% CI 0.43–0.61 mg/L), and 0.75 (95% CI 0.56–0.94 mg/L), respectively. The pooled concentration of fluoride in Iranian drinking water resources was 0.51 (95% CI 0.45–0.57 mg/L). The minimum and maximum concentrations of fluoride content were related to Kermanshah (0.19 mg/L) and Kerman (1.13 mg/L) provinces, respectively. The HQ of fluoride in the children and adults were 0.462 and 0.077, respectively as children are more vulnerable than adults. The HQ for children and adults was lower than 1 value. Therefore, there is no considerable non-carcinogenic risk for consumers due to drinking water in Iran. Although the non-carcinogenic of fluoride in drinking water was not significant, fluoride entry from other sources, such as food or inhalation, could endanger the health of the residents of Kerman and Bushehr provinces.