Xia Yuting, Ye Yunjie, Liu Mao, Wang Yang, Shang Li, Wang Peihua, Ding Zhen
Department for Environmental Health (Endemic Disease Control and Prevention), Jiangsu Provincial Center for Disease Control and Prevention, Jiangsu Road, 172, Nanjing, 210009, People's Republic of China.
Environ Geochem Health. 2025 Aug 10;47(9):369. doi: 10.1007/s10653-025-02685-5.
The combined impact of high iodine and high fluoride exposure has garnered increased attention. To determine whether exposure to high levels of fluoride and iodine in water has adverse effects on children's teeth. In this study, 582 children aged 8 to 12 from rural Jiangsu, China, were divided into three groups based on the concentrations of iodine and fluoride in their drinking water: a high fluoride and high iodine group (HFHI), a high fluoride group (HF), and a control group (CONTROL). We employed the ion-selective electrode method to measure fluoride levels in urine samples and used inductively coupled plasma mass spectrometry to assess urinary iodine (UI) levels. The prevalence and severity of dental fluorosis (DF) were determined using Dean's Index in accordance with WHO criteria. A logistic regression model was used to analyze factors related to dental fluorosis. The urinary fluoride (UF) regression coefficients were compared using the Z-test to assess their influence. The results indicate that the prevalence of DF was 52.5, 33.5, and 4.1% in the HFHI, HF, and CONTROL groups, respectively. There were statistically significant differences in both the prevalence and severity of DF among the groups (P < 0.001 for both). The dental fluorosis indexes (DFI) were calculated as 1.2, 0.7, and 0.1 for the HFHI, HF, and CONTROL groups, respectively. UF levels were positively associated with DF in the HFHI and HF groups, with adjusted odds ratios (OR) of 5.30 and 3.12, respectively. The Z-test results showed statistically significant differences (HFHI vs. CONTROL, P < 0.001; HF vs. CONTROL, P = 0.048; HFHI vs. HF, P < 0.001). UF levels > 1.4 mg/L and UI > 300 μg/L demonstrated a significant interaction in the HFHI group (OR = 9.62, 95% CI 2.70-18.36, P < 0.001) and Overall (OR = 9.15, 95% CI 2.71-16.58, P < 0.001). Simultaneous exposure to high iodine and high fluoride in water adversely impacts the incidence of DF in school-age children. It is recommended that monitoring of UI levels in children from high fluoride regions be enhanced.
高碘和高氟联合暴露的影响已受到越来越多的关注。为了确定饮用水中高氟和高碘暴露是否会对儿童牙齿产生不良影响。在本研究中，来自中国江苏农村的582名8至12岁儿童根据其饮用水中碘和氟的浓度分为三组：高氟高碘组（HFHI）、高氟组（HF）和对照组（CONTROL）。我们采用离子选择电极法测量尿样中的氟含量，并使用电感耦合等离子体质谱法评估尿碘（UI）水平。根据世界卫生组织标准，使用迪恩指数确定氟斑牙（DF）的患病率和严重程度。采用逻辑回归模型分析与氟斑牙相关的因素。使用Z检验比较尿氟（UF）回归系数以评估其影响。结果表明，HFHI组、HF组和对照组的DF患病率分别为52.5%、33.5%和4.1%。各组间DF的患病率和严重程度均有统计学显著差异（两者P均<0.001）。HFHI组、HF组和对照组的氟斑牙指数（DFI）分别计算为1.2、0.7和0.1。HFHI组和HF组中UF水平与DF呈正相关，调整后的优势比（OR）分别为5.30和3.12。Z检验结果显示有统计学显著差异（HFHI组与对照组，P<0.001；HF组与对照组，P = 0.048；HFHI组与HF组，P<0.001）。在HFHI组中，UF水平>1.4mg/L且UI>300μg/L表现出显著的交互作用（OR = 9.62，95%CI 2.70 - 18.36，P<0.001），总体上也是如此（OR = 9.15，95%CI 2.71 - 16.58，P<0.001）。同时暴露于水中的高碘和高氟会对学龄儿童的DF发病率产生不利影响。建议加强对高氟地区儿童UI水平的监测。
