ABSTRACT
Objective To identify changes in the occurrence of endemic fluorosis in order to provide scientific basis for making countermeasures. Methods Five villages from 14 counties of mild, moderate and severe fluorosis affected areas were selected by stratified cluster sampling every year in the whole province during 2006 - 2010. Water and urinary fluorine were determined by ion selective electrode method(GB/T 8538-1995); dental fluorosis of children 8-12 years old was diagnosed with Dean method; skeletal fluorosis was diagnosed according to "clinical indexing standards of endemic skeletal fluorosis "(GB 16396-1996), between 2006 and 2008, and "clinical diagnosis standard of endemic skeletal fluorosis"(WS 192-2008) between 2009 and 2010. Results A total of 25 diseased villages were surveyed, 14 with water sources changed, covered a resident population of 8005 people, beneficiary population 7154, and accounting for 89.37% of the resident population; not changed villages 11. In accordance with the "State drinking water health standards", in the 14 changed villages the fluoride in drinking water was qualified (≤ 1.20 mg/L), there were 3 schools whose water fluorine content exceeded the standard; among the 11 villages that did not change water sources 7 drinking water samples fluorine content exceeded the standard. Of the 8 to 12 years old children in villages with changed water sources, 363 of them were checked and 142 dental fluorosis were found, the detection rate of dental fluorosis was 39.12% (142/363); in villages with water sources not changed, 303 children were checked, the detection rate of dental fluorosis was 43.89%(133/303). Of sixteen and elder adults in water source changed villages, 6424 people were checked and 403 skeletal fluorosis were found, skeletal fluorosis detection rate was 6.27% (403/6424); 3572 people were checked in not changed villages, the detection rate of skeletal fluorosis was 13.89%(496/3572). In water sources changed areas, geometric mean of urinary fluoride was in the normal reference value(WS/T 256-2005, 1.40 mg/L)or less. Conclusions Endemic fluorosis is decreased in water improved areas, but in unimproved areas the disease is still severe, and control of endemic fluorosis is still an arduous task.
ABSTRACT
Objective To unveil the changes of endemic fluorosis in order to provide the scientific basis for making countermeasure. Methods Seven villages was selected as monitoring points in Qianan County of Jilin Province where drinking water was improved or was going tobe improved. Dental fluorosis was surveyed with Dean method and for urine fluoride content was tested using fluoride ion-selective electrode analysis in 8 - 12 years old children. Clinical skeletal fluorosis was detected in all residents of aged 16 and over in the beginning of the monitor and every 3 years. X-ray films were taken in those over 16 years old at the beginning of the monitor and every 5 years. Results Detectable rate of dental fluorosis was decreased compared with before(Weizi: 11.3% to 2.2%, Danzi: 16.3% to 12.1%, Houqi: 53.7% to 37.5%, Houju: 38.6% to 33.3%), and severity was declining, for example, in Dongnanjing, rate of being moderate was dropping from 11.3% to 7.8%, severe rate from 2.8% to 0;in Houqi: moderate rate from 16.7% to 0, severe rate from 1.9% to 0;in Houju, moderate rate from 1.4% to 0,severe rate from 1.4% to 0. However, detectable rate of dental fluorosis rose in Dabin from 61.7% to 70.0% and in Dongbin-donju from 52.7% to 71.1% due to increased fluorides in drinking water. Urine fluorides content in 8 - 12 years old children was decreased to normal level(1.5 mg/L) in most of monitoring spots, but in Dabin it still remained at a high level, being 4.03 and 4.57 mg/L before and after respectively. Detectable rate clinical skeletal fluorosis was between 11.1% - 25.7% among those aged 16 and over in 7 monitoring point in 1991 - 2006, however it increased year after year in Dabin (15.9%, 21.6% and 25.7% in 1991, 1993 and 1995). Positive X-ray rate for skeletal fluorosis was decreased from 54.9% to 24.0% in Dabin, from 40.7% to 23.5% in Dongbin-donju and from 28.6% to 20.4% in Dangnanjing. Conclusions Endemic fluorosis has been controlled attributed to improved drinking water and decreased fluorides content in drinking water. Combined methods are needed to decrease to the intake of fluorides to control the diseases.
ABSTRACT
Objective To explore the present condition of endemic arsenism, the implementation of control measures and the effect of the monitored county (Tongyu County) and the monitoring spot (Baiyintuhai Village) in 2006 and 2007. Methods According to the National Survey Scheme of Endemic Arsenism, the progress of anti-arsenic water in Tongyu, and the management and running of all engineering projects and the arsenic content in water were surveyed. The patients with endemic arsenism in Tongyu were generally surveyed. The arsenic content of the improved drinking water in Tongyu and the arsenic in urine of children aged 8-12 and adults over 18 years of age were determinted. The causes of resident death in the monitoring spot from the year of 2006 and 2007 were investigated. Arsenic content of drinking water and the urine of local residents was examined with "Model AFS-930 Double-Channel Atomic Fluorescence Spectrometer". Results There were 30 endemic arsenism areas, 157 areas with high arsenic content and all population of 57 576 in Tongyu. Six areas had improved water till 2006, where 20.0% of water had improved, and six water-improving projects were all running normally, benefiting a population of 1670. Eight high arsenic areas changed water, in a rate of 5.09%. Eight water-improving projects were functioning well, benefiting a population of 4350. Until 2007, 28 areas had improved water in Tongyu, accounting for 93.33%. These 28 projects were well running, covering a population of 7980. One hundred and fouty-eight high arsenic areas had changed water, reaching a rate of 94.27%. One hundred and fouty-eight projects changedg water were running normally, benefiting a population of 46 214. In the surveyed spots, arsenic content was between 0.004 mg/L and 0.005 mg/L in 2006 and between 0.010 mg/L and 0.021 mg/L in 2007, all in the normal range to the time being. The arsenic contents in urine of the children aged 8-12 in the monitoring spots were determinted, averaging at 0.024 mg/L in 15 samples, fluctuating between 0.005 mg/L and 0.048 mg/L in 2006. The average content in urine from adults was 0.019 mg/L in 53 samples, fluctuating between 0.005 mg/L and 0.087 mg/L in 2007. The arsenic contents in urine were all in the normal range in 2006 and 2007. In 2006 14 endemic arsenism patients, all in light symptoms, had been checked out, the morbidity being 6.19%. In 2007, 17 patients who were all in light symptoms were identified in a rate of 6.94%. There was no significant difference of morbidity between the two years(χ2=0.1059, P>0.05). Two patients died, unrelating with drinking high arsenic water in 2006 and 2007. Conclusions The prevention and control measures are well implemented in Tongyu. The water-improving projects are functioning well. The condition of endemic arsenism is slight and hasn't changed so much in these two years. The arsenic contents in urine of children and adults within the normal range, showing that improving water can control the occurrence and the development of endemic arsenism.