濮阳市饮水型地方性氟中毒病区改水效果分析

Effect of water improvement in drinking-water-borne endemic fluorosis areas in Puyang City

目的了解濮阳市饮水型氟病区儿童氟斑牙患病情况,评价改水效果,为病区改水工作提供依据。方法采取多阶段分层抽样方法,首先按照改水前水氟含量1.2~2.0 mg/L、2.1~4.0 mg/L和≥4.1 mg/L把饮水型氟中毒病区村分为3个层次,然后在每个层次随机抽取改水年限≤5年、6~8年、≥9年的病区村各1个,共9个村作为调查点。调查各调查点改水前和2015年饮水氟含量和8~12岁儿童氟斑牙患病情况。结果 2015年调查儿童1 126人,氟斑牙检出率为24.25%,低于改水前(64.10%)(χ~2=368.448,P<0.001)。改水6~8年和≥9年的调查点儿童氟斑牙检出率分别为16.31%、20.44%,差异无统计学意义(χ~2=2.270,P=0.132),2组均低于改水≤5年的调查点(42.69%)(χ~2=49.263、43.012,均P<0.001)。2015年调查男、女童氟斑牙检出率分别为23.54%、25.21%,差异无统计学意义(χ~2=0.418,P=0.518);8~12岁儿童氟斑牙检出率分别为18.71%、19.31%、29.82%、24.87%和35.77%,差异有统计学意义(χ~2=16.374,P<0.001),改水≤5年、6~8年的调查点,儿童年龄越小,氟斑牙检出率越低(χ_(趋势)~2=18.412、6.294,均P<0.05);改水≥9年的调查点各年龄组儿童氟斑牙检出率差异无统计学意义(χ_(趋势)~2=7.263,P=0.123)。除10岁年龄组外,同一年龄组的儿童,氟斑牙检出率与改水年限有关(均P<0.05)。结论濮阳市饮水型氟病区改水成效显著,改水年限对儿童氟斑牙患病有很大影响,改水5年以上可达到病区控制标准。

Objective To investigate the prevalence of dental fluorosis among children in drinking-water-borne fluorosis areas in Puyang City and to evaluate the effect of water improvement measures so as to provide a basis for implementing water improvement in endemic fluorosis areas. Methods Multi-stage stratified sampling method was used to select villages in drinking-water-borne fluorosis areas according to three levels of water fluoride contents（ including 1.2-2.0 mg/L,2.1-4.0 mg/L and ≥4.1 mg/L）before water improvement. Three villages with water improvement for ≤5 years,6-8 years and ≥9 years respectively in each level were randomly selected,so 9 villages were surveyed. In each surveyed village,fluoride content of drinking water and the prevalence of dental fluorosis in children aged 8-12 years before water improvement and in 2015 were surveyed. Results A total of 1,126 children were surveyed in 2015,and the detection rate of dental fluorosis in 2015 was lower than that before water improvement（24. 25% vs. 64.10%,χ^2= 368.448,P〈0.001）. No statistically significant difference was found in the detection rates of dental fluorosis in the surveyed villages with water improvement for 6-8 years and ≥9 years（ 16.31% vs. 20.44%,χ^2= 2.270,P = 0. 132）,but the above-mentioned detection rates were both lower than that of the surveyed villages with water improvement for ≤ 5 years（16.31% vs. 42.69%,20.44% vs. 42.69%,χ^2= 49. 263,χ^2= 43. 012,both P〈0. 001）. The detection rates of dental fluorosis in males and females in 2015 were 23.54% and 25.21% respectively,showing no statistically significant difference（ χ^2= 0.418,P =0. 518）. The detection rates of dental fluorosis in the age groups of 8,9,10,11 and 12 years were 18.71%,19.31%,29.82%,24. 87% and 35.77% respectively,with statistically significant differences（ χ^2= 16.374,P〈0.001）. In the surveyed villages with water improvement for ≤ 5 years and 6-8 years,the younger the children,the lower the detection rate of dental fluorosis（ χtrend^2=18.412,P〈0.001,χtrend^2= 6.294,P = 0.012）. No statistically significant difference was observed in the detection rate of dental fluorosis among the age groups of the surveyed villages with water improvement for ≥9 years（ χtrend^2= 7.263,P = 0.123）. The detection rates of dental fluorosis in the age groups of 8,9,11 and 12 years were related to the duration of water improvement（ all P〈0.05）.Conclusions Water improvement in drinking-water-borne endemic fluorosis areas in Puyang City is particularly effective. The duration of water improvement has a great influence on the prevalence of dental fluorosis in children,and fluoride content in drinking water improved more than 5 years can reach the control standards for the diseases areas.