饮水型地方性氟中毒病区改水后儿童尿氟与氟斑牙和龋齿的关系

Relationship between urinary fluoride level, incidences of dental fluorosis and caries of children in fluorosis areas ＇after change of water sources

目的评价和分析广东省汕头市潮南区改水后饮水型地方性氟中毒（地氟病）病区儿童尿氟含量与氟斑牙、龋齿检出率之间的关系，为改水后地氟病病区儿童健康风险评价提供依据。方法2009—2012年，在汕头市潮南区选择4个改水后的地氟病病区村（仙港村、范溪村、义英村和溪北村）与1个非地氟病病区村（上南村）进行6～12岁儿童龋齿、氟斑牙的检查。并从检查对象中按年龄分层抽取600名儿童，进行尿氟含量的测定。结果4个地氟病病区村仙港村、范溪村、义英村和溪北村的改水年限分别为6、14、15、17年。仙港村儿童尿氟中位数（0．62mg／L）高于上南村（0．48mg／L，P〈0．05）；范溪村、义英村、溪北村儿童尿氟中位数（0．51、0．36、0．27mg／L）低于或接近于上南村，组间比较差异有统计学意义（F=44．29，P〈0．05）；仙港村、范溪村、义英村和溪北村8—12岁儿童氟斑牙检出率分别为31．0％（321／1037）、7．8％（22／283）、7．5％（88／1166）和3．9qc（31／785），上南村为5．9％（77／1309），组间比较差异有统计学意义（X^2=481．89，P〈0．05）；仙港村、范溪村、义英村和溪北村儿童龋齿检出率分别为32．O％（332／1037）、65．0％（184／283）、56．3％（657／1166）和45．2％（355／785），上南村为（49．7％，651／1309），组间比较差异有统计学意义（X^2=109．21，P〈0．05）；不同尿氟的儿童氟斑牙检出率组间比较差异有统计学意义（x2：32．05，P〈0．05），不同尿氟的龋齿检出率组间比较差异无统计学意义（x。=8．28，P〉0．05），且随着尿氟含量的改变而呈现U型曲线的变化趋势。结论4个地氟病病区村儿童尿氟含量、氟斑牙检出率与改水时间有关，随着改水时间的增加，尿氟含量和氟斑牙检出率均降低，而龋齿检出率和尿氟含量有关，与改水时间无关。

Objective To assess and analyze the relationship between urinary fluoride level, incidences of dental fluorosis and caries of children in fluorosis areas after change of water sources, and to provide a basis for health risk assessment of children in fluorosis areas after change of water sources. Methods From 2009 to 2012, Xiangang, Fanxi, Yiying, Xibei Villages in fluorosis areas with water improvement project and Shangnan Village in a non-fluorosis area were selected randomly as investigation subjects. Dental fluorosis and caries of children aged 6 - 12 in the 5 villages were examined and 600 children among them were chosen based on ages to measure their urinary fluoride. Results Water sources were changed for 6, 14, 15, 17 years in Xiangang, Fanxi, Yiying and Xibei villages, respectively. Urinary fluoride levels of children between the 5 villages were significantly different （F = 44.29, P 〈 0.05）, urinary fluoride level of children in Xiangang village （0.62 mg/L） was higher than that of children in Shangnan Village （0.48 mg/L, P 〈 0.05）, but all other three villages, Fanxi, Yiying and Xibei （0.51, 0.36, 0.27 mg/L） were lower or near that of Shangnan Village. The incidences of dental fluorosis of children aged 8 - 12 in Xiangang, Fanxi, Yiying, Xibei and Shangnan Villages were 31.0%（321/1037）, 7.8%（22/283）, 7.5% （88/1166）, 3.9% （31/785 ）, and 5.9% （77/1309）, respectively, and the differences were statistically significant （X2 = 481.89, P 〈 0.05）. The incidences of caries of children in Xiangang, Fanxi, Yiying and Xibei Villages were 32.0% （332/1037）, 65.0% （184/283）, 56.3% （657/1166） and 45.2% （355/785）, respectively, Shangnan Village was 49.7 % （ 651 / 1309 ）, and the differences were statistically significant （X2 = 109.21, P 〈 0.05 ）. The incidence difference of children dental fluorosis with different urinary fluoride were statistically significant between groups （X2 = 32.05, P 〈 0.05） ;but the incidence difference of caries was not statistically significant（x2 = 8.28, P 〉 0.05）, and it was changed with the level of urinary fluoride in a U-shaped curve. Conclusions The level of urinary fluoride and the incidence of dental fluorosis of children in the 4 villages after water improvement are related to the time of water improvement. The levels of urinary fluoride and the incidence of dental fluorosis are decreased with increased time of water improvement. The incidence of caries is related to the levels of urinary fluoride, but not related to the time of water improvement.