Objective:To learn about the operation of fluoride reduction and water improvement projects, the current situation of water fluoride level and the changing trend of fluorosis in drinking water-borne endemic fluorosis areas in Shaanxi Province, and to evaluate the effect of prevention and control measures.Methods:From March 2014 to December 2021, 15 endemic villages in drinking water-borne endemic fluorosis areas of Dali, Dingbian, Jingbian, Jingyang and Liquan counties in Shaanxi Province were selected as monitoring villages to investigate the operation of water improvement projects. Water samples were collected, and the water fluoride level was detected according to the "Standard Examination Methods for Drinking Water - Nonmetal Parameters" (GB/T 5750.5-2006). "Diagnosis of Dental Fluorosis" (WS/T 208-2011) was done to detect dental fluorosis in all children aged 8 - 12 who were born and lived in the monitoring village. Using "Diagnostic Standard for Endemic Skeletal Fluorosis" (WS/T 192-2008) and "Determination of Fluoride in Urine - Ion Selective Electrode Method" (WS/T 89-2015), X-ray examination and urine fluoride level test were performed on adults over 25 years old who had lived in the monitoring village for more than 5 years, respectively.Results:From 2014 to 2021, a total of 122 water improvement projects were investigated, all of which were in normal operation. The qualified rate of water fluoride increased from 81.25% (13/16) in 2014 to 100.00% (11/11) in 2021. A total of 5 595 children aged 8 - 12 were examined, 1 790 children with dental fluorosis were detected, with a detection rate of 31.99%. The detection rate of dental fluorosis in children decreased from 52.05% (304/584) in 2014 to 9.68% (93/961) in 2021, showing an overall downward trend (χ 2trend = 533.76, P < 0.001). In 2014, 791 adults were examined, and 256 patients with skeletal fluorosis were detected, the detection rate was 32.36%. In 2019, 770 adults were examined, and 88 patients with skeletal fluorosis were detected, with a detection rate of 11.43%. The detection rate of skeletal fluorosis in adults in 2019 was lower than that in 2014, and the difference was statistically significant (χ 2 = 99.54, P < 0.001). In 2014, 754 adult urine samples were collected, and the geometric mean of urine fluoride was 2.571 mg/L. In 2019, 770 adult urine samples were collected, and the geometric mean of urine fluoride was 1.292 mg/L. The geometric mean of urine fluoride in adults in 2019 was lower than that in 2014, and the difference was statistically significant ( Z = - 12.74, P < 0.001). Conclusions:From 2014 to 2021, the water improvement projects in drinking water-borne endemic fluorosis areas in Shaanxi Province are running normally, and the qualified rate of water fluoride has increased. The incidence of dental fluorosis in children and skeletal fluorosis in adults has decreased. In the later stage, it is necessary to continuously strengthen the monitoring and management of water improvement projects to prevent the rebound of water fluoride from causing residents' illness.

Objective:To learn about the changes of the condition of coal-burning-borne endemic arsenism, the use of improved stoves and the formation of health-related behaviors in Shaanxi Province, and evaluate the effect of prevention and control measures.Methods:From 2015 to 2020, according to the "Implementation Plan for Monitoring Coal-burning-borne Endemic Arsenism in Shaanxi Province", regular field surveys were carried out in 4 natural villages, 2 counties in Ankang City and Hanzhong City, Shaanxi Province, to learn about the basic prevention and control situation in the monitoring village. Using the simple random sampling method, 10 families in each village were selected to investigate the use of stoves and the formation of health-related behaviors, and 5 of these families were selected to collect coal samples for arsenic content determination in accordance with the "Determination of Arsenic in Coal" (GB/T 3058-2008). According to the "Diagnosis of Endemic Arsenicosis" (WS/T 211-2015), the condition of the people exposed to high arsenic coal in the monitoring village was investigated. Urine samples of 30 adult patients (half males and half females) with arsenic poisoning were collected, the content of arsenic in urine was determined by the "Urine-Determination of Arsenic-Silver Diethyldithiocarbamate-Triethanolamine-Spectrophotometric Method" (WS/T 28-1996).Results:A total of 240 households were monitored in the past 6 years, and the quality conformance and correct utilization rates of improved stoves in the households monitored in the disease areas remained at 100.00% in 2018 - 2020. The utilization rate of clean energy increased from 75.00% (30/40) in 2015 to 100.00% (40/40) in 2018 - 2020 (χ 2trend = 25.5, P < 0.001). The 73.75% (177/240) of households using a variety of clean energy. From 2018 to 2020, the correct drying, storage and pre-processing washing rates of corn and pepper continued to reach 100.00% (40/40). The arsenic content of coal ( n = 120) in the disease areas was (118.09 ± 57.91) mg/kg, ranging from 16.70 to 280.94 mg/kg. The detection rate of arsenic poisoning decreased from 6.34% (231/3 646) in 2015 to 2.90% (109/3 754) in 2020 (χ 2trend = 121.8, P < 0.001), and no skin cancer or Bowen's disease was detected. The geometric mean of arsenic content in urine ( n = 720) was 0.038 1 mg/L, ranging from 0.000 5 to 0.312 9 mg/L. Conclusions:The condition of coal-burning-borne endemic arsenism areas in Shaanxi Province has reached the national elimination standard. The quality and correct utilization rate of improved stoves and the rate of using clean energy have increased. The healthy-related behaviors the people in the endemic areas have been basically formed. The prevention and control work has achieved good results.

Objective:To explore any effect of training assisted by a pelvic rehabilitation robot on trunk control and walking after cerebral infarction.Methods:Forty cerebral infarction survivors with hemiplegia were randomly divided into an experimental group and a control group, each of 20. Both groups were given routine neurological medication and rehabilitation training, while the experimental group was additionally provided with 20 minutes of robot-assisted gait training daily, five times a week, for 4 weeks. Before and after the intervention, the motor function, walking function, trunk control and pelvic movement were assessed using a simplified version of the Fugl-Meyer assessment (FMA-LL), functional ambulation categories (FAC) and the trunk control test (TCT).Results:After the treatment, significant improvement was observed in all of the above measurements in both groups. The average FMA-LL, FAC and TCT results of the experimental group as well as their average pelvic lateral displacement, height displacement, rotation angle and roll angle were all significantly superior to the control group′s averages.Conclusions:Robot-assisted training can effectively improve lower limb motor functioning, trunk control, walking and pelvic motion after cerebral infarction, with better curative effect than routine rehabilitation training alone.

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.

Objective:To explore the effect of a pelvis-assisting rehabilitation robot on lower limb function and knee proprioception after cerebral infarction.Methods:Forty hemiplegic cerebral infarction survivors were randomly divided into an experimental group and a control group, each of 20. Both groups were given routine neurological medication and rehabilitation training, while the experimental group was additionally provided with 20 minutes of robot-assisted gait training daily, five times a week for four weeks. Before and after the intervention, motor function, balance, walking function and knee joint proprioception were assessed using the simplified Fugl-Meyer lower limb assessment, the Berg balance scale, functional ambulation categorization and the Humac Norm isokinetic tester.Results:After the treatment, significant improvement was observed in all of the above measurements in both groups, but the improvements were significantly greater in the experimental group.Conclusions:Robotic pelvic assistance can effectively improve lower limb motor function, balance, knee proprioception and walking after cerebral infarction.

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 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 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.