2014-2018年内蒙古自治区农村集中式供水氟化物含量变化情况分析

Analysis on changes of fluoride in rural centralized water supply in Inner Mongolia Autonomous Region from 2014 to 2018

目的 了解内蒙古自治区(简称内蒙古)农村集中式供水氟化物含量达标情况及分布规律,为调整防控措施提供参考依据。方法 2014-2018年,在内蒙古77个旗(县、区)分别设立836、947、1 033、1 068和1 099个农村集中式供水监测点,每年于每个监测点的丰水期和枯水期采集出厂水和末梢水等水样,检测氟化物含量,根据时间、水期(丰水期和枯水期)、水样类型(出厂水和末梢水)、水处理方式(常规处理、沉淀和过滤、仅消毒、未处理)、区域[东部区(呼伦贝尔、兴安盟、通辽和赤峰)、中部区(呼和浩特、包头、乌兰察布和锡林浩特)和西部区(鄂尔多斯、巴彦淖尔和阿拉善)]进行描述性分析,并采用ArcMAP 10.2软件进行可视化分析。结果 2014-2018年,分别采集水样3 251、3 671、4 058、4 087和4 395份,氟化物含量中位数分别为0.69、0.70、0.69、0.64和0.66 mg/L,氟化物年达标率分别为80.31%(2 611/3 251)、81.83%(3 004/3 671)、83.14%(3 374/4 058)、85.91%(3 511/4 087)和84.57%(3 717/4 395)。不同年份氟化物达标率比较差异有统计学意义(χ^2=51.748,P < 0.01),且氟化物达标率呈逐年上升趋势(χ^2=41.140,P < 0.01)。丰水期和枯水期氟化物达标率分别为83.36%(8 128/9 750)、83.29%(8 089/9 712),二者比较差异无统计学意义(χ^2=0.020,P > 0.05)。出厂水和末梢水氟化物达标率分别为83.55%(6 583/7 879)、83.17%(9 628/11 576),二者比较差异无统计学意义(χ^2=0.485,P > 0.05)。不同水处理方式氟化物达标率比较差异有统计学意义(χ^2=192.014,P < 0.01),常规处理和仅消毒处理氟化物达标率较高,分别为95.51%(404/423)、94.44%(986/1 044);未处理氟化物达标率最低,为81.75%(13 073/15 991)。东部、中部、西部区氟化物达标率比较差异有统计学意义(χ^2=629.256,P < 0.01),其中东部区达标率最高,为89.17%(7 337/8 228);中部区最低,为74.67%(5 391/7 220)。可视化结果显示,阴山山脉以北、大兴安岭以西的中部区氟化物达标率明显偏低。结论 2014-2018年内蒙古农村集中式供水氟化物达标率逐年上升,降氟改水工程取得了一定的成效。但仍有部分农村地区水质氟化物达标率偏低,主要分布于阴山山脉以北、大兴安岭以西的内蒙古中部区。建议当前防控重点应由"全局把控"过渡到"精准控氟",还需从政策落实和技术革新两方面针对氟污染重点区域实施治理工程,确保农村居民的饮水安全。

Objective To understand the situation and distribution of fluoride in rural centralized water supply in Inner Mongolia Autonomous Region(Inner Mongolia for short),and provide a reference for adjustment of prevention and control measures.Methods From 2014 to 2018,836,947,1033,1068,1099 rural centralized water supply monitoring sites were designated in 77 banners(counties,districts)separately in Inner Mongolia,and factory water and tip water samples were collected during plentiful phase and exhausted phase every year,respectively,and fluoride content was tested.Descriptive analysis was done according to time,water period(plentiful phase and exhausted phase),water sample type(factory water and tip water),water treatment method(conventional treatment,sedimentation and filtration,only disinfection and untreated),area distribution[eastern region(Hulunbuir,Xing'an League,Tongliao and Chifeng),central region(Hohhot,Baotou,Ulanqab and Xilinhot)and western region(Ordos,Bayannur and Alashan)],and the results were analyzed visually by ArcMAP 10.2.Results From 2014 to 2018,3251,3671,4058,4087 and 4395 water samples were collected,the medians fluoride were 0.69,0.70,0.69,0.64 and 0.66 mg/L,and the annual compliance rates of fluoride were 80.31%(2611/3251),81.83%(3004/3671),83.14%(3374/4058),85.91%(3511/4087)and 84.57%(3717/4395).The difference of compliance rate of fluoride in rural centralized water supply in different years was statistically significant(χ^2=51.748,P<0.01),and the compliance rate of fluoride showed an increasing trend with the years(χ^2=41.140,P<0.01).The compliance rates of fluoride in plentiful phase and exhausted phase were 83.36%(8128/9750)and 83.29%(8089/9712),respectively,and the difference was not significant statistically(χ^2=0.020,P>0.05).As for water sample type,the compliance rates of fluoride in factory water and tip water were 83.55%(6583/7879)and 83.17%(9628/11576),and the difference was not significant statistically(χ^2=0.485,P>0.05).The difference of compliance rate of fluoride in different water treatment methods was statistically significant(χ^2=192.014,P<0.01).The compliance rates of fluoride in water with conventional treatment and only disinfection were higher[95.51%(404/423)and 94.44%(986/1044)];and the untreated water had the lowest compliance rate of fluoride[81.75%(13073/15991)].There was a statistically significant difference in compliance rates of fluoride in the eastern,central and western regions(χ^2=629.256,P<0.01),with the eastern region had the highest compliance rate of 89.17%(7337/8228);the central region had the lowest compliance rate of 74.67%(5391/7220).The visualization results showed that the compliance rate of fluoride was obviously low in the central region north of Yin Mountains and west of Greater Higgnan Mountains.Conclusions From 2014 to 2018,the compliance rates of fluoride in rural centralized water supply increase year by year,and some achievements have been made in fluorine reduction and water improvement project in Inner Mongolia.However,there are still some rural areas with low level of water fluoride compliance rates which mainly distribute in the central region of Inner Mongolia in the north of Yin Mountains and west of Greater Higgnan Mountains.The current focus of prevention and control should be shifted from"general control"to"precise fluorine control".In the future,it is necessary to implement treatment projects in key areas of fluorine pollution from the aspects of policy implementation and technological innovation to ensure the drinking water safety of local rural residents.