Impact of Arsenic methylation of population exposed to chronic arsenic through drinking water / 中华地方病学杂志

Objective To investigate the arsenic methylation level of people chronically exposed to different levels of arsenic in drinking water.Methods A cluster sampling method was used to select 874 cases that had drank different concentration arsenic-contaminated water from arsenic endemic area in Bayannaoer City.They were divided into four groups according to arsenic exposure level:control (≤ 10 μg/L),low (＞ 10-50 μg/L),medium (＞ 50-200 μg/L) and high groups (＞ 200 μg/L),146,155,224,349 cases,respectively.The content of arsenic in drinking water and the arsenic species in urine were analyzed by inductively coupled plasma mass spectrometry (ICPMSS) and the results were expressed as median.Results The inorganic arsenic (iAs),monomethylarsonic acid (MMA),dimethylarsinic acid (DMA),and total-arsenic (tAs) in urine of low,medium and high groups increased following increasing of arsenic exposure level (x2 =605.08,609.96,615.83,628.64,all P ＜ 0.017) and iAs％,MMA％ and MMA/DMA significantly increased following increasing of arsenic exposure level (x2 =112.30,56.60,86.47,all P ＜ 0.017).DMA％,PMI and SMI significantly decreased following increasing of arsenic exposure level (x2 =125.80,112.30,86.47,all P ＜ 0.017).In the four groups,iAs％ of female were 11.39％,12.28％,13.47％ and 17.58％,they were significantly lower than those of male's (15.52％,16.19％,17.45％,21.86％,Z =-4.22,-3.79,-4.60,-6.71,all P ＜ 0.05);and DMA％ were 76.95％,74.05％,72.76％,and 68.64％ in the four groups respectively,and the PMI of female were 0.89,0.88,0.87,and 0.82,both DMA％ and PMI were significantly higher than those of male in each group (71.17％,69.39％,67.36％,61.29％,0.84,0.84,0.83,0.78,Z =-4.00,-3.34,-5.50,-7.24,-4.22,-3.79,-4.60,-6.71,all P ＜ 0.05).In control group,arsenic metabolites levels of people were not significantly different in the three age groups (all P ＞ 0.05).Compared to the ≤30 age group,the MMA,DMA and tAs of 31-45 age group increased and DMA,DMA％,PMI of ≥46 age group increased while iAs％ decreased in high group (μg/L:72.71 vs 109.13,307.90 vs 419.50,505.59 vs 684.60,307.90 vs 418.26;64.31％ vs 68.45％,0.79 vs 0.83,20.71％ vs 17.35％,x2 =10.72,10.24,8.20,10.24,9.89,20.96,20.96,all P ＜ 0.017).Compared to the 31-45 age group,DMA％ and PMI of ≥46 age group increased while iAs％ decreased (64.91％ vs 68.45％,0.80 vs 0.83,20.14％ vs 17.35％,x2 =9.89,20.96,20.96,all P ＜ 0.017).Conclusion There is a significant dose response relationship between arsenic metabolites and arsenic exposure level,and arsenic methylation is related to gender and age.

Analysis of surveillance results of water-borne endemic arsenism in Inner Mongolia in 2015 / 中华地方病学杂志

Objective To understand the changes of arsenic poisoning in drinking water arsenic poisoning areas in Inner Mongolia Autonomous Region,to provide a scientific basis for timely adjustment of local arsenic poisoning prevention and control measures.Methods In accordance with the requirements of the national "Surveillance Scheme of Drinking-Water-Borne Endemic Arsenism",38 villages were selected from 8 cities as monitoring sites in Inner Mongolia Autonomous Region in 2015.The situation of the villages in improving water quality and operation of the arsenic reducing projects was investigated,water samples were collected to detect water arsenic content of all the monitoring villages exposed or previously exposed to high arsenic water in the resident population,and 30 adult patients with arsenic poisoning were tested urine arsenic level.Results Thirty-eight monitored villages had changed the water sources;the change rate was 100.00％ (38/38).Water arsenic content qualified projects were 17,covering 36 villages.The project with water arsenic content exceeded the national standard was 1,the rate of exceeded standard was 5.56％ (1/18),covering 2 monitored villages.In the 36 water arsenic content qualified natural villages,4 163 people were examined,and arsenic poisoning patients detection rate was 10.21％ (425/4 163).The incidence of mild,moderate,severe and skin cancer cases was 7.59％ (316/4 163),1.68％ (70/4 163),0.86％ (36/4 163) and 0.07％ (3/4 163),respectively,no new cases and new skin cancer cases.In the natural villages where the content of arsenic in water exceeded the standard,461 resident people who were drinking high arsenic water were examined.The detection rate of arsenic poisoning patients was 3.69％ (17/461),no moderate,severe,new and skin cancer cases.A total of 1 107 patients with arsenic poisoning were tested for urinary arsenic levels in the 36 villages with normal water available and water arsenic levels in the range of 0.000-0.441 mg/L with a median of 0.011 mg/L.The content of urinary arsenic in 60 patients with arsenic poisoning was detected in the 2 natural villages with the arsenic content exceeded the standard.The range was 0.030-0.268 mg/L and the median was 0.155 mg/L.Conclusions The projects of anti-arsenic water have effects in Inner Mongolia Autonomous Region.But there are still water projects with water arsenic content exceeded the standard,which seriously affects the health of residents,and the water management and maintenance of water projects needs to be strengthened.

Relationship between hair selenium and arsenism induced by arsenic derived from coal combustion / 中华地方病学杂志

Objective To study the relationship between hair selenium content and arsenism among population from endemic arsenism area caused by coal combustion in the southern of Shaanxi Province.Methods Four high-arsenic-exposed villages in southern Shaanxi Province were selected as the study area,and the nonarsenic-exposed villages nearby were selected as the control area,90 hair samples of residents exposed to high arsenic in the study area and 14 hair samples of residents in the control area were collected.Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine the contents of arsenic and selenium in hair samples.Selenium/hair arsenic (Se/As) value was calculated,and the relationship between selenium content in hair samples and arsenicosis was analyzed.Results The geometric mean of selenium concentration in hair from the study area was 8.72 mg/kg,which was significandy higher than that from the control area (0.54 mg/kg,t =9.811,P ＜ 0.05).However,selenosis case was not found in the study area.Selenium content in hair was not obviously correlated with arsenism (r =0.075,P ＞ 0.05),while the Se/As value was negatively associated with the grade of arsenism (P ＞ 0.05).The geometric mean of selenium content in hair of female from the study area was 12.79 mg/kg,which was higher than that in hair of male (6.5 mg/kg,t =1.738,P ＜ 0.01).Meanwhile,the Se/As value in hair of female from the study area (1.15) was significantly higher than that in hair of male (0.65,t =3.218,P ＜ 0.05).Conclusions The environment of the study area is polluted by arsenic and selenium derived from stone-coal burning.Antagonism between arsenic and selenium might reduce the toxicity of selenium.Therefore,selenosis is not found in the study area.In addition,antagonism between arsenic and selenium might also induce lower prevalence of arsenism for female in the studly area.

Correlation between blood aryl hydrocarbon receptor, cytochrome P-450 1A1 mRNA expression and skin changes in people with endemic arsenic poisoning / 中华地方病学杂志

Objective Though measuring the expression levels of blood aryl hydrocarbon receptor (AhR) and cytochrome P-450 1A1 (CYP1A1),to explore the relationship between the expression levels and chronic arsenic poisoning induced skin changes.Methods Totally 233 residents were selected in Hanggin Rear Banner arsenic exposure area of Bayannur City,according to water arsenic concentrations,these people were divided into control (＜ 10 μg/L,55 people),low (10-＜ 100 μg/L,47),medium (100-＜ 200 μg/L,45) and high (≥200 pg/L,86) arsenic exposure groups.Real-time PCR was used to detect the expression levels of blood AhR and CYP1A1 mRNA,which were presented in median and quartile [M (Q1-Q3)],and the relationships between their expression levels and keratosis,depigmentation of skin were analyzed.Results The relative expression levels of AhR and CYP1A1 mRNA in high-dose groups were 3.18 × 10-3 (2.42 × 10-3-4.45 × 10-3) and 1.58 × 10-3 (0.80 ×10-3-2.73 × 10-3),which were higher than those in control groups [2.30 × 10-3 (1.53 × 10-3-3.20 × 10-3) and 1.00 × 10-3 (0.59 × 10-3-2.09 × 10-3)],and the difference were statistically significant (all P ＜ 0.05).Compared with control group,the detectable rates of arsenic poisoning,keratosis and depigmentation of skin were higher,and the differences were statistically significant (x2 =20.187,15.848,21.595,all P ＜ 0.05).The detectable rates of arsenic poisoning,keratosis and depigmentation of skin were increased with increase of water arsenic concentrations (x2 =19.012,15.269,16.868,all P ＜ 0.05).Compared with normal [2.54 × 10-3 (1.79 × 10-3-3.43 × 10-3),2.57 × 10-3 (1.78 × 10-3-3.52 × 10-3)],AhR mRNA relative expression levels [4.45 × 10-3 (3.47 × 10-3-8.04 × 10-3),4.45 × 10-3 (4.02 × 10-3-6.25 × 10-3)] of degree Ⅲ keratosis and depigmentation of skin were increased,and the differences were statistically significant (all P ＜ 0.05).Conclusions Chronic arsenic exposure affects the expression level of AhR and CYP1A1 mRNA.Blood AhR mRNA expression may have relationship with endemic arsenic poisoning induced skin change,but blood CYP1A1 mRNA expression may have nothing to do with endemic arsenic poisoning induced skin change.

Expression and significance of thyroid hormone receptors mRNA of residents exposed to arsenic via drinking water / 中华地方病学杂志

Objective To detect thyroid hormone receptors (TRs) mRNA expression of subjects exposed to different levels of arsenic,to further study the endocrine disturbing effect of arsenic.Methods Molecular epidemiological method was used,in drinking water type of endemic arsenic poisoning areas,which were divided into control (＜ 10 μg/L),low (10-＜ 100 μg/L),medium (100-＜ 200 μg/L) and high (≥200 μg/L) dose groups based on the drinking water arsenic concentrations.According to the gender stratification,a total of 273 (control,low,medium and high dose groups were 58,49,66,100,respectively) residents were chosen.To carry out the questionnaire,urine arsenic determination,electrocardiographic examination.Real-time PCR was used to detect blood TRs mRNA expression.Results TRα mRNA relative expression levels in the control,low,medium and high dose groups were (12.2 ± 5.7) × 10-4,(12.2 ± 5.0) × 10-4,(12.3 ± 5.4) × 10-4,(12.2 ± 4.3) × 10-4,respectively,the differences were not statistically significant (F =0.109,P ＞ 0.05).TRβ mRNA relative expression levels were all low,the control,low,medium and high dose groups were (5.7 ± 4.1) × 10-6,(8.6 ± 7.6) × 10-6,(6.3 ± 4.2) × 10-6 and (6.2 ± 3.8) ×10~,respectively,the differences were statistically significant (F =2.938,P ＜ 0.05).The levels of TRβ mRNA relative expression changed with increased content of arsenic in water and urine trends in inverse U-shaped curves (R2 =0.035,0.067,all P ＜ 0.05).TRβ mRNA relative expression in low dose group was higher than that in control group,the difference was statistically significant (P ＜ 0.05);TRβ mRNA relative expression in high dose group was lower than that in low dose group,the difference was statistically significant (P ＜ 0.05).Arsenic induced arrhythmia which most displayed sinus bradycardia;the prevalence of arrhythmia in the control,low,medium and high dose groups were 12.1％ (7/58),10.2％ (5/49),13.6％ (9/66),19.4％ (19/98),respectively,the differences were not statistically significant (x2 =2.877,P＞ 0.05).Heart rate was positively associated with the level of TRβ mRNA relative expression in lg value (r =0.218,P ＜ 0.05).Conclusion Chronic arsenic exposure can disturb TRβ mRNA expression;there is a possible relationship between TRβ mRNA abnormal expression and arrhythmia caused by arsenic.

Trend analysis of endemic arsenism in the monitored areas of the disease in 2010 - 2012 in Inner Mongolia / 中华地方病学杂志

Objectives To monitor the residents prevalence of endemic arsenism in the disease affected areas in Inner Mongolia, so as to provide feasible suggestions for control of arsenism in the future. Methods Monitoring data were obtained from the Project of Endemic Disease Prevention Granted by Central Government in 2010 - 2012, and the conditions of arsenism patients from 38 endemic arsenic villages were analyzed among different year, age and gender. Results The detection rate of arsenism of the 38 surveillance villages was 7.38%(517/7 004) in 2010, 7.10%(482/6 784) in 2011 and 6.62% (431/6 514) in 2012. The arsenism patients of mild;moderate and severe cases from 2010 to 2012, accounted for 74.47% (385/517), 74.27% (358/482), 75.17% (324/431); 16.83% (87/517), 16.60% (80/482), 15.78% (68/431) and 8.7% (45/517), 9.13% (44/482), 9.05% (39/431), respectively. For skin lesions, the detection rates of keratosis, pigmentation and depigmentation from 2010 to 2012, were 8.08%(566/7 004), 7.90%(536/6 784), 7.77%(506/6 514);3.27%(229/7 004), 3.29%(223/6 784), 2.87%(187/6 514) and 6.68% (468/7 004), 6.63% (450/6 784), 5.82% (379/6 514), respectively, showed a declining trend. It also showed a declining trend with age, and the patients were mainly 40 years old people and older, and the highest detection rate was in the 60- 70 years old group[15.54%(143/920)、14.72%(135/917)、13.36%(136/1 018)]. For gender distribution, the detection rate of the three years was higher in male than female [male 8.24%(300/3 639), 7.99%(283/3 542), 7.71%(260/3 372);female 6.45%(217/3 365), 6.14%(199/3 242), 5.44%(171/3 142),χ2=8.24, 8.77, 13.54, all P〈0.01]. Conclusion There is no big change of arsenism conditions in 2010-2012, with a slight declining trend.

Clinical characteristics of drinking-water type endemic arsenism in population lived in the diseased areas before and after water improvement in Inner Mongolia / 中华地方病学杂志

Objectives To analyze the clinical characteristics of drinking-water type endemic arsenism in population lived in the diseased areas before and after water improvement in Inner Mongolia,so as to assess the natural development and the effects of human intervention measures.Methods Residents of four villages lived in Hangjinhouqi Bayinnaoer city Inner Mongolia were followed-up and their skin lesions were examined in 2004 (before water improvement),2010 (complete water improvement),2014 (after water improvement).Meanwhile,blood pressure and heart rate of the subjects were measured.The arsenic poisoning skin damage indexing was in accordance with endemic arsenic poisoning diagnostic criteria (WS/T 211-2001).Results Totally,229,122,161 people were investigation in 2004,2010,2014,respectively.The clinical grading of arsenic exposed population were mainly normal and suspicious cases in 2004,accounting for 61.6％ (141/229) and 22.7％ (52/229),respectively.The clinical grading of normal,suspicious,mild and severe cases were 20.5％ (25/122),31.1％ (38/122) and 48.4％ (59/ 122),respectively,in 2010,which were significantly different compared with those of 2004 (x2 =68.53,P ＜ 0.01).The clinical grading percentages of normal and suspicious of the subjects in 2014 were 46.6％ (75/161) and 39.8％ (64/161),respectively,which were significantly different compared with those of 2010 (x2 =45.22,P ＜ 0.01).Meanwhile,91 subjects examined in 2004 were re-examined in 2010 and 47 subjects examined in 2010 were reexamined in 2014.Totally,12 cases were migitation,accounting for 13.2％ (12/91),52 cases were aggravation,accounting for 57.1％ (52/91) in 2010,and 25 cases were migitation,accounting for 53.2％ (25/47),9 cases were aggravation,accounting for 19.1％ (9/47) in 2014.The differences of skin lesion transition between these two periods were significant (x2 =28.66,P ＜ 0.05).In addition,the systolic pressures and diastolic pressure of the subjects were (132.19 ± 21.21),(126.99 ± 18.32),(147.69 ± 22.65);(84.88 ± 14.13),(76.52 ± 10.08),(84.39 ± 13.89)mmHg in 2004,2010 and 2014,respectively,which declined in 2010 compared with them of 2004 (all P ＜ 0.05) and raised in 2014 compared with them of 2010 (all P ＜ 0.01).The heart rate of the subjects were (76.05 ± 12.56),(78.86 ± 11.69),(82.05 ± 11.26)times/min.The heart rate of the subjects raised in 2010 and 2014 compared with that of 2004 (all P ＜ 0.05).Conclusion The skin lesions induced by arsenism could be effectively alleviated through water improvement,but the late stage changes such as the cardiovascular system injury are still worthy of attention.