From: Developmental fluoride neurotoxicity: an updated review
Reference | Study location, year | No. in high-exposure group | No. in reference group | Age range (or mean), years | Fluoride exposure | Outcome measure | Results | |
---|---|---|---|---|---|---|---|---|
Assessment | Mean or range (mg/L) | |||||||
[96] | China, 2014 | 123 | 42 | 8–12 | Urine | 3.03 (urine, short-term); 2.33 (urine, long-term); 1.34 (urine, ref) | RSPMa | Fluoride exposure was negatively associated with children’s IQ |
[97] | China, 2015 | 26 (moderate/severe dental fluorosis) | 8 (normal/questionable dental fluorosis) | 6–8 | Drinking water, urine | 2.66 (water, moderate/severe); 1.0 (water, normal/questionable); 2.44 (urine, moderate/severe); 0.45 (urine, normal/questionable) | WRAMLb; WISC-IVc | Moderate and severe fluorosis were significantly associated with deficits in digit span scores. |
[98] | India, 2015 | 215 | 214 | 6–12 | Drinking water | 2.41 (water, high); 0.19 (water, ref) | RCPMd | IQs of highly exposed children were significantly lower than those with low-level exposure |
[99] | China, 2015 | 84 | 96 | 7–13 | Drinking water, urine | 1.40 (water, high); 0.63 (water, ref); 2.40 (urine, high); 1.10 (urine, ref) | CRT-RCe | Fluoride exposure was negatively associated with children’s IQ |
[100] | India, 2016 | 23 (severe dental fluorosis) | 4 (normal dental fluorosis) | 6–18 | Groundwater and urine | 2.11 (water); 0.45–17.00 (range, urine) | CRT-RCe | IQ was negatively correlated with degree of dental fluorosis |
[101] | China, 2017 | 68 | 50 | 3–12 months | Coal burning vs. control | Mothers in exposed group had dental fluorosis | MDI & PDI (CDCC)f | MDI & PDI in exposed group were significantly lower than those in the control group |
[102] | China, 2017 | 167 | 120 | 8–12 | Coal burning vs. control | Dental fluorosis index 53.9% in exposed group | RSPMa | IQ was lower in children with high fluoride exposure (not significant) |
[103] | China, 2018 | 221 | 100 | 8–12 | Drinking water | 1.2 (water, high); 0.25 and 0.78 (water, controls) | CRT-RCe | IQ was lower in children from endemic areas and in those with dental fluorosis |
[104] | Sudan, 2018 | 775 (total) | N/a | 6–14 | Drinking water | 0.01–2.07 (water) | School performance based on method adopted by MoE | Inverse relationship between fluoride in drinking water and average school performance |
[105] | China, 2018 | 134 | 134 | 8–12 | Dental fluorosis | N/a | CRT-RCe | IQ was lower in children from endemic areas |
[106] | Egypt, 2018 | 186 | 814 | 4.6–11 | Drinking water | 0.92–3.75 (water) | DAPg | Decreased scores in children from areas with elevated fluoride in drinking water |
[107] | China, 2018 | 1250 | 1636 | 7–13 | Drinking water and urine | 2.00 + 0.75 (water, high); 1.37 + 1.08 (urine, high); 0.50 + 0.27 (water, ref); 0.41 + 0.49 (urine, ref) | CRT-RC2e | IQ was lower in children at higher fluoride in water and urine and at greater severity of dental fluorosis |
[108] | China, 2019 | 25 | 27 | 8–12 | Drinking water | N/a | CRT-RC2e | IQ was lower at elevated fluoride exposure |
[109] | China, 2020 | 571 (total) | N/a | 7–13 | Drinking water, urine | 1.39 + 1.01 (water); 1.28 + 1.30 (urine) | CRT-RC2e | Low to moderate fluoride exposure is associated with alterations in thyroid function and lower IQ |