0.05). Conclusion High fluoride may cause children intelligence decrease.

Objective Identify the arsenic and fluorin contents in coal from major producing coal mines in south of Shaanxi,providing a scientific foundation for the formulation of the prevention strategy.Methods In the 6 major coal mine areas governed by Ankang and Hanzhong city,the 62 mines with comparatively large production scales and sales locally,which may have some effective forces on the causing of the local arsenic and fluorin poisoning,were inveatigated,on-the-spot sampling are carried out,the fluorine in coal was determined by the combustion-hydrolysis/fluoride-ion selective electrode method and the arsenic in coal was determined by the atomic fluorescence.Results The maximum of the fluoride content in coal from the 62 investigated coal mines was 3 053.04 mg/kg,and the minimum was 6.58 mg/kg;the arithmetic mean was 1 034.30 mg/kg;the geometric mean was 656.85 mg/kg;The maximum of arsenic content in coal was 484.71mg/kg,and the minimum was 29.64 mg/kg;the arithmetic mean was 197.64 mg/kg,the geometric mean was 174.29 mg/kg.Conclusion The contents of fluoride and arsenic are seriously exceeded the standard limits in the 62 investigated coal mines,especially in stone coal mines.

Objective To investigate the urinary arsenic levels of exposed population in various forms of and total arsenic (TAs) content as well as their relationship with arsenic poisoning in southern Shaanxi arsenic poisoning area.Methods According to the historical data of the investigation on arsenic poisoning,11 disease villages were chosen as survey sites in Ziyang and Pingli counties,Ankang city;three neighbor villages were chosen as control sites in Baihe.Baihe was a non-endemic arsenic poisoning area county,which had the same natural environment and living habits.In the survey sites,people over the age of 40 were selected for epidemiological investigation in both heating and non-heating seasons,and 40 urine samples were collected at each severity levels of the disease and in different seasons.Meantime,20 urine samples of the same age group were collected in the control sites in each season.Hydride generation-atomic fluorescence spectrometry (HG-AFS) was used to determine TAs,liquid chromatography-hydride generation-atomic fluorescence spectrometry (LC-HG-AFS) was used to determine the amount of inorganic trivalent arsenic (As3+),dimethylarsine (DMA),monomethylarsine (MMA) and inorganic pentavalent arsenic (AS5+),and the various forms and TAs were compared between different survey sites,severity levels,ages,sexes,and seasons.Results The medians of TAs,As3+,DMA,primary methylation index (PMI),and secondary methylation index (SMI) in diseased area (35.3,2.2,24.5 μg/L;0.84,0.90) were significantly higher than those of the control group (16.0,0.6,10.3 μg/L;0.78,0.81;Z =-9.069,-7.314,-8.913,-2.183,-3.853,P ＜ 0.01 or ＜ 0.05),and the medians of TAs,As3+,DMA,and SMI (31.6,2.0,23.1 μg/L;0.91) of the normal population in the diseased area were significantly higher than those of the control group (16.0,0.6,10.3 μg/L;0.81;Z =-7.164,-6.136,-7.023,-2.916,all P ＜ 0.01).Illness had positive correlations with TAs,DMA,and ages (r =0.370,0.367,0.594,all P ＜ 0.01).Men arsenic poisoning detection rate,TAs,As3+,and DMA (59.9％,37.4,2.5,25.2 μg/L) were significantly higher than those of women (22.4％,30.0,1.6,20.9 μg/L;x2 =54.878,P ＜ 0.01;Z =-3.332,-4.449,-2.681,all P ＜ 0.01).The medians of As3+,MMA,As5+,PMI,and SMI in the heating season (1.5,2.1,1.4 μg/L;0.87,0.92) were significantly different from those in the non-heating season (2.6,3.3,3.0 μg/L;0.82,0.88;Z =-6.870,-5.512,-8.542,-2.262,-4.544,P ＜ 0.01 or ＜ 0.05).Conclusions The TAs,As3+,and DMA of urine samples are related to local arsenic background,so they have some reference value for determination of diseased areas.Men are more susceptible to arsenic poisoning than women.

Objective To investigate the relationship between levels of arsenic and selenium in hair and urine of patients with arsenic poisoning caused by coal-burning.Methods Based on the Standard of Diagnosis for Endemic Arsenism (WS/T 211-2001),about fifty arsenism or suspicious patients over 40 years old were separately selected from Haoping Town and Shuang'an Town of Ziyang County,and the high-arsenic stone coal of Haoping Town was consumed in these two towns,all patients were divided into suspicious,light,moderate,and severe groups.Five coal samples were collected from homes of patients with arsenic poisoning,which were crushed to pieces and sufficiently mixed,0.5 kg of the crushed coal was collected by quartering method to determine arsenic and selenium content;at the same time,5 water samples were collected in homes of patients with arsenic poisoning to determine arsenic and selenium content;in each investigation site,5 ploughs were selected according to the five directions as east,west,south,north and centre,to collect 15-30 cm soil of plough layer,after blending with four points method of shrinkage,1.0 kg was collected to determine arsenic and selenium content in the soil;the urine of all patients instantly and 0.5 g hair sample within 20 mm from the scalp on occiput were collected to determine arsenic and selenium content.Dual channel atomic fluorescence spectrophotometer was used to measure the arsenic and selenium content in the coal,water,soil,urine and hair samples.The contents of arsenic and selenium in coal,water and soil were expressed as （x） ± s;the contents of arsenic and selenium in urine and hair were expressed as medium (M) and quartile range (QR).Results The patients with arseniasis in moderate and severe groups from Shuang'an Town accounted for 9.8％ (5/51) of the total number of patients;the patients in moderate and severe groups from Haoping Town accounted for 39.2％ (20/51).Compared between the two towns of the proportion of arsenic poisoning clinical index,the difference was statistically significant (x2 =31.224,P ＜ 0.01).Compared between Haoping Town and Shuang'an Town,the arsenic contents of soil [(150.71 ± 127.10),(71.10 ± 22.75) mg/kg],water [(0.004 1 ± 0.000 2),(0.006 3 ± 0.000 4) mg/L],urine [0.025 2 (0.023 2),0.026 7 (0.025 6) mg/L] and hair [2.54 (3.52),2.81 (5.98) mg/kg] were not significantly different (Z =-0.913,-1.776,-0.079,-0.544,all P ＞ 0.05).The selenium contents of soil [(5.93 ± 5.76) mg/kg],water [(0.036 9 ± 0.001 8) mg/L],urine [0.056 3 (0.152 2) mg/L] and hair [3.65 (5.43) mg/kg] in Shuang'an Town were higher than those of Haoping Town [(2.41 ± 1.03) mg/kg,(0.006 1 ± 0.000 6) mg/L,0.015 6 (0.013 4) mg/L and 1.52 (2.05) mg/kg],the differences were statistically significant (Z =-2.619,-2.611,-4.765,-2.485,all P ＜ 0.01).There was a positive correlation between hair arsenic and arsenic in clinical grading (r =0.874,P ＜ 0.01);there was a negative correlation between hair selenium and arsenic in clinical grading (r =-0.400,P ＜ 0.01).Conclusions High selenium environment affects the severity of patients with arsenic poisoning,indicating that selenium may promote arsenic metabolism and reduce arsenic accumulation in vivo.Selenium may have an antagonist effect on arsenic.

Objective To investigate the current situation of coal-burning-borne endemic arsenism in the disease affected areas,the usage of anti-arsenism stove and the formation of related behavior;,to evaluate the control effect,so as to provide a basis for development of control strategies.Methods Surveillances were carried out according to the provisions and requirements of The Surveillance Project for Shaanxi Institute Coal-Burning-Borne Endemic Arsenicosis (Trial.).Four villages in two counties of Ankang city and Hanzhong city in Shaanxi Province were monitored in 2010-2014.Using simple random sampling method,10 families in each village were randomly selected to survey the situation of the stove used and related behavior changes.Five households in each village were randomly selected; arsenic level in coal was determined; high arsenic exposed population was investigated according to Endemic Arsenism Diagnostic Criteria (WS/T 211-2001).Urine samples of 30 patients with arsenism were randomly selected to determine the arsenic content.Results The proper utilization rate and the qualified households of improved stoves and iron stoves were all low; the correct drying rate and the correct storage rate of peppers and corns were higher than 95％.The washing rate of corns and peppers before eating were all 100％.A total of 100 copies of coal samples were tested and the arsenism content was between 12.295-455.827 mg/kg,and the geometric mean value of the arsenism content was (91.819 ± 80.989)mg/kg.Seventeen thousand eight hundred and fifty-five individuals were investigated and 1 232 cases of arsenism were diagnosed in the 4 villages; the prevalence rate was 6.90％ (1 232/17 855); urinary arsenism content was between not detected-0.287 mg/L; and the geometric mean value of the arsenic content was 0.033 mg/L.Conclusions The coal-burning-borne endemic arsenism in Shaanxi is in a prevalent state; many anti-arsenism stoves are out of order; and the proper utilization rate is low.To strengthen the disease surveillance,health education and management of anti-arsenism stoves are key measures in control of coal-burning borne endemic arsenism in the future.

Objective To investigate the influence of fluoride and arsenic exposure on children's intelligence and growth development.Methods The illness seriously and lightly affected areas in the coal-burning-borne arsenism and fluorosis areas in the south part of Shaanxi were selected as survey sites from 2011 to 2012,while the illness non-affected areas as controls.Children's IQ was tested,dental fluorosis and growth level of 8-12-year-old students in the school were investigated by random sampling,and the differences of children's IQ and the level of their growth among different groups were analyzed.Urine samples of the children were collected to determine the fluoride and the arsenic content.Results In the illness seriously affected,lightly affected and nonaffected areas,the medians of urinary fluoride of children were 1.96,0.81 and 0.54 mg/L,respectively; and the medians of their urinary arsenic were 0.023,0.019 and 0.018 mg/L,respectively.The average IQ levels were 101.22 + 15.97,104.83 ± 12.78 and 107,92 + 13.62,respectively.In illness seriously affected,lightly affected and non-affected areas,the differences of their height,weight,chest circumference and lung capacity between groups(x2 =36.549,25.859,28.021 and 45.627,all P ＜ 0.01) were significantly different.The height,weight,chest circumference and lung capacity of the children in illness seriously affected(136 cm,31 kg,64 cm,1 432 ml) and lightly affected areas (137 cm,30 kg,65 cm,1 433 ml) were all less than those of the illness non-affected areas (141 cm,34 kg,67 cm,1 660 ml,Z =-5.858,-4.151,-4.196,-4.500,-5.189,-3.240,-6.698 and -4.008,all P ＜ 0.01) ; lung capacity of children in illness seriously affected areas was less than that of the illness lightly affected areas (Z =-2.395,P ＜ 0.05).Their urinary fluoride and arsenic levels were negatively correlated with their IQ(r =-0.560,-0.353,all P ＜ 0.05).Conclusions Fluorine and arsenic exposure is not conducive to children's intellectual development and growth.We propose to strengthen the measure of changing stove furnace in order to provide a healthy growth environment for children.

Objective To investigate the operating situation of water-improvement projects,fluoride content in drinking water and the tendency of drinking-water-born fluorosis in Shaanxi Province.Methods In the areas of drinking-water-born endemic fluorosis,15 villages in 5 counties were randomly selected as monitoring sites,by random number table method.Ten water-improvement projects in each county were randomly selected to investigate the operating situation and 1 water sample from the tap water of each water-improvement project was collected to determine the fluoride level in 2009-2011.For water-improvement villages,the operating situation of the water-improvement projects was monitored and 1 water sample from the tap water of each water-improvement project was collected to determine the fluoride level,and for water-unimprovement villages,1 water sample from each direction of the east,west,south,north and middle of the villages was collected,respectively,to determine fluoride level in 2009-2013.Dental fluorosis of 8-12 years old children and X-ray skeletal fluorosis of adults 25 years old were examined in each village.Water fluoride was tested according to the Standard Testing Methods for Drinking Water (GB/T 5750.5-2006).Diagnosis of dental fluorosis was based on the Dean's Standard (2009 to 2011 edition) and WS/T 208-2011 (2012 to 2013 edition) and that of the adults X-ray skeletal fluorosis was based on WS 192-2008.Results The number of investigated water-improvement projects was 146 in survey counties and 68 in survey villages.The normal operation rates were 97.95％ (143/146) and 98.53％ (67/68),respectively.The qualified rates of water fluoride were 53.42％ (73/146) and 61.67％ (42/68),respectively.The populations covered by the qualified water-improvement projects were 18.93％ and 8.70％ of the total water-improvement projects.And,78.95％ (15/19) of the water-unimproved villages had a water fluoride level of over 1.2 mg/L in the drinking water.In the water-improved villages,children dental fluorosis rate reached an average of 41.62％ (1 061/2 549) and decreased year by year from 2009 to 2013 (except 2012) (x2 =46.818,P ＜ 0.01),but in the water-unimproved villages,the rate was 64.73％(1 167/1 803) on average and did not go down year by year,and the difference was statistically significant (x2 =225.557,P ＜ 0.01).Adults X-ray skeletal fluorosis rate was 22.55％(124/550) in the water-improved villages and 30.00％ (60/200) in the water-unimproved villages in 2009,and the difference was statistically significant (x2 =4.402,P ＜ 0.05).In 2013,adults X-ray skeletal fluorosis rate was 34.17％(219/641) in the water-improved villages and 24.67％(37/150) in the water-unimproved villages,and the difference was statistically significant (x2 =5.010,P ＜ 0.05).Conclusions The measures of water improvement against fluoride have showed definitely control effects,but excess fluoride in drinking water is still a health problem,and the prevalence of fluorosis is not controlled completely.The control work remains to be further strengthened and deepened.

Objective To establish a method for simultaneous determination of arsenic and selenium in hair by hydride generation atomic fluorescence spectrometry.Methods The A and B of the hair samples were digested via the wet method,and the arsenic and selenium contents were determined simultaneously with a dual channel atomic fluorescence spectrophotometer.Standard blank solution was continuously determined for 11 times,the detection limit was calculated according to the blank solution three times the standard deviation.Hair samples A and B were continuously determined for 11 times,and the precision was determined according to the coefficient of variation (CV).The hair samples C and D were did 11 times of standard addition experiment,the standard added was close to the sample low value.The accuracy was determined by the standard recovery rate.Results The lowest detection limits of arsenic and selenium were 0.081,0.036 μg/L,the precisions of arsenic and selenium in sample A were (0.694 9 ± 0.024 2) and (1.930 2 ± 0.098 5) μg/g,the CV were 3.54％ and 5.09％.The precisions of arsenic and selenium in sample B were (6.212 2 ± 0.137 3) and (8.282 2 ± 0.266 8) μg/g,the CV were 2.21％ and 3.22％;the recovery rates of sample C of arsenic and selenium were 96.30％ ～ 110.00％ and 94.80％ ～ 110.00％;the recovery rates of sample D of arsenic and selenium were 93.63％ ～ 108.20％ and 97.03％ ～ 108.34％.Conclusions The method using hydride atomic fluorescence for determination of arsenic and selenium in the hair has been successfully established.This method is simple and easy to operate,with high sensitivity and good accuracy and precision,high recovery,less matrix interference,and less reagent consumed etc.It is worth promoting in prevention and control of endemic diseases.

Objective:To investigate the arsenic content in internal and external environment of the people in drinking-water-borne endemic arsenic poisoning areas in Shaanxi Province, the status quo of the disease and the management and services of the existing patients, so as to provide a theoretical basis for evaluating the effect of prevention and control measures on drinking-water-borne endemic arsenic poisoning.Methods:From 2019 to 2020, in accordance with the requirements of the "Notice of Shaanxi Provincial Health Commission on Issuance of Monitoring Plans for Key Endemic Diseases such as Kashin-Beck Disease" and "Monitoring Plans for Drinking Water Arsenic Poisoning in Shaanxi Province", investigation was carried out in all villages of drinking-water-borne endemic arsenic poisoning in Mianxian County of Hanzhong City, Shanyang County and Zhen'an County of Shangluo City to understand the operation of water improvement project. One terminal water sample was collected to determine the content of arsenic in water, and permanent population of the whole village who are and/or had been exposed to excessive arsenic water in the past were examined for arsenic poisoning and the disease condition was determined according to the standard of "Diagnosis of Endemic Arsenicosis" (WS/T 211-2015). Five villages were randomly selected, and 50 people were selected from each village. Real-time urine sample was collected to determine the content of urinary arsenic. At the same time, management and services of the existing arsenic poisoning patients was investigated.Results:A total of 13 villages were investigated, all of which had been improved in water quality, and all 13 water improvement projects were operating normally, with arsenic content < 0.01 mg/L. A total of 12 577 people were examined, and 417 cases of arsenic poisoning were detected, with a detection rate of 3.32%. No new arsenic poisoning case and arsenic-related skin cancer case had been detected. A total of 260 urine samples were detected, and the geometric mean value of urinary arsenic (< 0.001 mg/L) was lower than the safety guideline value of human urinary arsenic (0.032 mg/L). The existing arsenic poisoning patients (417 cases) were included in health management and contracted services.Conclusions:Shaanxi Province has reached the elimination standard of drinking-water-borne endemic arsenic poisoning. In the future, more attention should be paid to the management of water improvement project, as well as to strengthen health promotion and management services for existing patients to consolidate the effects of prevention and control.

Objective:To explore the effect of robot-assisted training and repetitive transcranial magnetic stimulation (rTMS) on the lower limb function of hemiplegic stroke survivors.Methods:Forty hemiplegic stroke patients were randomly divided into a treatment group ( n=20) and a control group ( n=20). Both groups were given routine rehabilitation training and robot-assisted walking training, but the treatment group was additionally treated with rTMS at 1Hz applied to the primary motor cortex M1 area at an intensity of 80% of the resting motor threshold. The stimulation time was 5 seconds at 5-second intervals, 600 pulses each time, five times a week for 8 weeks. Lower limb motor function, balance and walking function were assessed before and after the intervention using the Fugl-Meyer assessment for the lower extremities, the Berg balance scale and the Holden walking function scale. Results:There was no significant difference between the two groups in any measurement before the training, but after the intervention all of the measurements had improved significantly in both groups, with the average Fugl-Meyer score, Berg score and Holden grading significantly better in the treatment group.Conclusion:Repetitive transcranial magnetic stimulation can improve the effectiveness of robot-assisted walking training in improving lower limb motor function, balance and walking after a stroke.