title: Probabilistic risk assessment of Chinese residents' exposure to fluoride in improved drinking water in endemic fluorosis areas.
abstract: Studies have yet to evaluate the effects of water improvement on fluoride concentrations in drinking water and the corresponding health risks to Chinese residents in endemic fluorosis areas (EFAs) at a national level. This paper summarized available data in the published literature (2008-2016) on water fluoride from the EFAs in China before and after water quality was improved. Based on these obtained data, health risk assessment of Chinese residents' exposure to fluoride in improved drinking water was performed by means of a probabilistic approach. The uncertainties in the risk estimates were quantified using Monte Carlo simulation and sensitivity analysis. Our results showed that in general, the average fluoride levels (0.10-2.24 mg/L) in the improved drinking water in the EFAs of China were lower than the pre-intervention levels (0.30-15.24 mg/L). The highest fluoride levels were detected in North and Southwest China. The mean non-carcinogenic risks associated with consumption of the improved drinking water for Chinese residents were mostly accepted (hazard quotient < 1), but the non-carcinogenic risk of children in most of the EFAs at the 95th percentile exceeded the safe level of 1, indicating the potential non-cancer-causing health effects on this fluoride-exposed population. Sensitivity analyses indicated that fluoride concentration in drinking water, ingestion rate of water, and the exposure time in the shower were the most relevant variables in the model, therefore, efforts should focus mainly on the definition of their probability distributions for a more accurate risk assessment.
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China.
authors.forename: Li E
authors.initials: LE
authors.lastname: Zhang
authors.affiliation: Department of Biomedical Engineering, School of Preclinical Medicine, Guangxi Medical University, Nanning 530021, China.
authors.forename: Daizheng
authors.initials: D
authors.lastname: Huang
authors.affiliation: Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wei
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Qin
authors.affiliation: Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China.
authors.forename: Songfeng
authors.initials: S
authors.lastname: Ou
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China. Electronic address: email_zyf@163.com.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Zou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D060766:Drinking Water / Q000009:adverse effects / Q000737:chemistry*; D019353:Endemic Diseases / Q000517:prevention & control / Q000706:statistics & numerical data; D004781:Environmental Exposure / Q000009:adverse effects* / Q000517:prevention & control / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D005459:Fluorides / Q000008:administration & dosage / Q000009:adverse effects* / Q000032:analysis*; D009050:Fluorosis, Dental / Q000453:epidemiology* / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D008962:Models, Theoretical; D011786:Quality Control; D018570:Risk Assessment; D060753:Water Quality / Q000592:standards*; D014881:Water Supply; D055815:Young Adult
chemical_list: D060766:Drinking Water; D005459:Fluorides
keywords: Drinking water; Fluoride; Fluorosis; Health risk; Probabilistic