A study on arsenical dermatosis in rural community of West Bengal

The spatial distribution of chronic arsenicosis due to consumption of arsenic contaminated tube well water in different districts of West Bengal was gradually unfolding since 1983. Arsenical dermatosis was found to be the commonest and earliest manifestation of chronic arsenic toxicity. This study was conduct in Baruipur block of South 24 Parganas district of West Bengal. Total 313 people selected from three randomly selected villages with reported arsenic contamination in tube well water and 342 people living three randomly selected villages without such evidence of contamination were examined as control population. 5.97% of exposed population and 2.05% of unexposed population showed melanosis (p < 0.01). Moreover, 5.11% of exposed population and 0.88% of unexposed population showed keratosis (p < 0.01). The prevalence of dermatosis among exposed population was also seen to have increased with increasing age, from 7.19% in 0-19 year age group to 37.50% in above 40 year group (p < 0.001). Prevalence was also found to be more with increase in level of contamination. The prevalence rate of dermatosis among unexposedgroup was 2.92%. But age adjusted prevalence rate among exposed group was 19.08% at arsenic contamination level of 0.487 ppm. Mean arsenic concentration in nail and hair samples of exposed group was also found higher than the prescribed limit.     

Respiratory effects and arsenic contaminated well water in Bangladesh

Arsenic in drinking water causes a widespread concern in Bangladesh, where a major proportion of tube wells is contaminated. Arsenic ingestion causes skin lesions, which is considered as definite exposure. A prevalence comparison study of respiratory effects among subjects with and without arsenic exposure through drinking water was conducted in Bangladesh. Exposed participants were recruited through health awareness campaign programs. Unexposed participants were randomly selected, where tubewells were not contaminated with arsenic. A total of 169 individuals participated (44 exposed individuals exhibiting skin lesions; 125 unexposed individuals). The arsenic concentrations ranged from 136 to 1000 micro g l(-1). The information regarding respiratory system signs and symptoms were also collected and the analyses were confined to nonsmokers. The crude prevalence ratio for chronic bronchitis and chronic cough amounted to 2.1 (95% CI 0.7-6.1). The prevalence ratios for chronic bronchitis increased with increasing exposure, i.e., 1.0, 1.6, 2.7 and 2.6 using unexposed as the reference. The prevalence ratios for chronic cough were 1.0, 1.6, 2.7 and 2.6 for the exposure categories, using the same unexposed as the reference. The dose-response trend was the same (P < 0.1) for both conditions. These results add to evidence that long-term ingestion of arsenic exposure can cause respiratory effects.     

Arsenic Contamination of Ground Water and its Health Impact on Population of District of Nadia, West Bengal, India

Background:

The global health impact and disease burden due to chronic arsenic toxicity has not been well studied in West Bengal.

Objective:

To ascertain these, a scientific epidemiological study was carried out in a district of the state.

Materials and Methods:

Epidemiological study was carried out by house-to-house survey of arsenic affected villages in the district of Nadia. A stratified multi-stage design has been adopted for this survey for the selection of the participants. A total number of 2297 households of 37 arsenic affected villages in all the 17 blocks were surveyed in the district.

Result:

Out of 10469 participants examined, prevalence rate of arsenicosis was found to be 15.43%. Out of 0.84 million people suspected to be exposed to arsenic, 0.14 million people are estimated to be suffering from arsenicosis in the district. Highest level of arsenic in drinking water sources was found to be 1362 μg/l, and in 23% cases it was above 100 μg/l. Majority of the population living in the arsenic affected villages were of low socio-economic condition, inadequate education and were farmers or doing physical labour. Chronic lung disease was found in 207 (12.81%) subjects among cases and 69 (0.78%) in controls. Peripheral neuropathy was found in 257 (15.9%) cases and 136 (1.5%) controls.

Conclusion:

Large number of people in the district of Nadia are showing arsenical skin lesion. However, insufficient education, poverty, lack of awareness and ineffective health care support are major factors causing immense plight to severely arsenic affected people.     

Evaluation of biochemical changes in chronic arsenic poisoning among Bangladeshi patients

An estimated 40 million people in Bangladesh have been suffering from arsenic toxicity-related diseases because of drinking water contamination with high levels of naturally occurring arsenic. To evaluate the biochemical changes in chronic arsenic exposure, a total of 115 exposed subjects diagnosed as arsenicosis patients were examined and interviewed, and 120 unexposed volunteers were enrolled in this study. Drinking water, urine and peripheral blood samples were collected from all participants and analyzed. The average levels of arsenic in the drinking water and spot urine samples of the arsenicosis patients were 218.1 microg/L and 234.6 microg/L, respectively, and duration of exposure was 7.6 +/- 5.2 yrs that ranged from 1-25 yrs. Prevalence of diabetes mellitus among chronic arsenic-exposed subjects was about 2.8 times higher than the unexposed subjects. The activities of alkaline phosphatase were significantly elevated in the patients, 197 U/L compared to 149 U/L in the controls, but alanine transaminase and aspartate transaminase were mostly normal. The patients had significantly lower levels of serum creatinine, 0.97 mg/dL compared to 1.15 mg/dL in the controls; but had significantly elevated levels of total protein, 84 g/L and 77 g/L respectively. The mean level of inorganic phosphate in the serum of arsenicosis patients was 6.4 mg/dL compared to 4.6 mg/dL in the unexposed subjects and the level was significantly higher, indicating substitution of the pentavalent arsenate for the phosphate ion causing underutilization of the latter. Evaluation of the lipid profiles showed while the levels of triacylglycerol were not much different, the patients had significantly lower levels of cholesterol, HDL-cholesterol and LDL-cholesterol compared to the unexposed subjects. These findings suggest significant changes in biochemical parameters in human arsenic toxicity.     

四川省金川县饮水型砷中毒流行病学调查

目的　了解金川县砷中毒的病情及流行特征 ,查明引起砷中毒的高砷来源。方法　对经检测饮水砷含量超标的村进行病情调查 ,同时对该村的地理、地貌、饮用水源及环境中砷污染情况进行调查 ,测定内环境和外环境介质中砷含量。结果　饮水砷含量检测有 3个共饮泉水源超标 ,最高饮水砷含量达 0 2 87mg/L ,超标 5倍多 ;共调查 375人 ,查出患者 6 2人 ,患病率为 16 5 3% ,其中年龄最小 11岁 ,最大 83岁。结论　四川省存在地方性砷中毒。共饮泉水中砷含量超标是引起该病流行的主要因素。由于没有其他环境砷污染 ,水砷含量高是自然形成的 ,因此属于饮水型地方性砷中毒     

Mutual interaction between nutritional status and chronic arsenic toxicity due to groundwater contamination in an area of Terai, lowland Nepal

OBJECTIVE: To reveal the inter-relationship between nutritional status and arsenic toxicity. DESIGN: Cross-sectional study. SETTING: A survey in an area of lowland Nepal, where a high prevalence of both skin manifestation and malnutrition was observed. Daily arsenic intake was estimated by measuring the arsenic concentration and daily consumption of the drinking water. PARTICIPANTS: Adult villagers (248 men and 291 women). About half were classified as "underweight" (body mass index <18.5), indicating poor nutritional status. MAIN RESULTS: Arsenic intake was negatively correlated with body mass index and substantially increased the prevalence of underweight individuals, among whom the prevalence of skin manifestations was 1.65-fold higher than normal weight individuals. When exposure level was considered, the prevalence of skin symptoms was consistently higher in the underweight than in the normal group. Although enhanced susceptibility in men was apparent by the increased prevalence of cutaneous symptoms, no sex difference was observed in the prevalence of underweight individuals related with exposure to arsenic. CONCLUSIONS: The present data suggested that exposure to arsenic is associated with an increased prevalence of underweight, a serious health problem in developing countries, which in turn is associated with increased skin manifestation of arsenic poisoning.     

Comparison of health effects between individuals with and without skin lesions in the population exposed to arsenic through drinking water in West Bengal, India

A study was conducted to explore the effect of arsenic causing conjunctivitis, neuropathy and respiratory illness in individuals, with or without skin lesions, as a result of exposure through drinking water, contaminated with arsenic to similar extent. Exposed study population belongs to the districts of North 24 Parganas and Nadia, West Bengal, India. A total of 725 exposed (373 with skin lesions and 352 without skin lesions) and 389 unexposed individuals were recruited as study participants. Participants were clinically examined and interviewed. Arsenic content in drinking water, urine, nail and hair was estimated. Individuals with skin lesion showed significant retention of arsenic in nail and hair and lower amount of urinary arsenic compared to the group without any skin lesion. Individuals with skin lesion also showed higher risk for conjunctivitis ((odd's ratio) OR: 7.33, 95% CI: 5.05-10.59), peripheral neuropathy (OR: 3.95, 95% CI: 2.61-5.93) and respiratory illness (OR: 4.86, 95% CI: 3.16-7.48) compared to the group without any skin lesion. The trend test for OR of the three diseases in three groups was found to be statistically significant. Again, individuals without skin lesion in the exposed group showed higher risk for conjunctivitis (OR: 4.66, 95% CI: 2.45-8.85), neuropathy (OR: 3.99, 95% CI: 1.95-8.09), and respiratory illness (OR: 3.21, 95% CI: 1.65-6.26) when compared to arsenic unexposed individuals. Although individuals with skin lesions were more susceptible to arsenic-induced toxicity, individuals without skin lesions were also subclinically affected and are also susceptible to arsenic-induced toxicity and carcinogenicity when compared to individuals not exposed to arsenic.     

Unventilated indoor coal-fired stoves in Guizhou province, China: reduction of arsenic exposure through behavior changes resulting from mitigation and health education in populations with arsenicosis

We report the results of a coordinated mitigation effort aimed at reducing arsenic (As) exposure in three counties of Guizhou province, China. Mitigation occurred in 2005 and encompassed 21 villages with 47,000 inhabitants, who were exposed to high levels of As in their diet through consumption of As-contaminated chili peppers and corn dried over unventilated stoves that burned coal containing high levels of As. The coal was mined by villagers from local pits. Inhalation of air that contained high levels of As contributed to approximately 25% of the daily As intake of 6-9 mg. Before mitigation, a baseline survey of 45,364 residents in 2004 identified more than 2,800 individuals with arsenicosis. The survey also found that many residents were aware of the health effects of As in general but lacked in-depth understanding of the link between coal use and arsenicosis. Consequently, an overwhelming majority (> 95%) continued to use high-As coal. This survey provided the basis for a health education campaign that promoted lifestyle changes coupled with the shutting down of local coal pits and the installation of 10,000 new stoves with chimneys for ventilation. The cost of the mitigation was about 4 million Yuan RMB (US$500,000) and was financed mostly by the government. A postmitigation response survey in 2005 found that > 85% of the residents now associate the use of coal with arsenicosis; > 90% correctly learned to operate the new ventilated stoves; and > 90% dry corn and chili peppers outdoors in the sun. Urinary As concentrations in the region decreased from 0.198 +/- 0.300 mg/L (n = 144) in 2004 to 0.049 +/- 0.009 mg/L (n = 50) in 2005 in individuals with arsenicosis (p < 0.01), which is consistent with the behavior changes.     

Arsenicosis in Bangladesh: prevalence and socio-economic correlates

The potential effects of arsenic-contaminated drinking water on health are of concern, but our understanding of the risk factors of arsenicosis remains limited. This study assessed the prevalence of and socio-economic differentials in arsenic-associated skin lesions in a rural community in Bangladesh. Data were collected from a village where the Bangladesh Rural Advancement Committee has operated a health surveillance system and a community-based arsenic mitigation project since 1999. In total, 1654 residents in the study village were examined in May 2000 for arsenic-associated lesions on their skin. Socio-economic information was extracted from the surveillance system database covering the village. Nearly 2.9% of the study population had clinical manifestations of arsenic poisoning. The prevalence of arsenicosis was associated with age, sex, education and the economic status of the household. Multivariate analysis identified age and economic status as significant predictors of arsenicosis controlling for education and gender. In conclusion, a clear understanding of the socio-economic distribution of arsenicosis in different demographic and socio-economic groups will be useful in identifying the high-risk groups from arsenic-affected communities. More studies are needed to design effective interventions to mitigate the effects of arsenic in Bangladesh.     

石门雄黄矿附近地区慢性砷中毒流行病学特征

为研究石门雄黄矿附近地区人群慢性砷中毒的患病率及其分布特点,采用现况调查研究方法,以雄贡矿排放洗矿水河流下游的三个村庄为污染区,另选一个远离矿区无污染的村庄为对照,每个村子各选取在当地居住五年以上,无职业性砷接触史的居民约２００人,进行体检并填写健康调查问卷。     

Prevalence of arsenicosis in terai, Nepal

This paper summarizes the findings of surveys on arsenicosis cases conducted during 2001-2004 in terai, Nepal, by governmental and non-governmental organizations in their respective project areas and by some national and international institutes. Studies were conducted in six arsenic-contaminated districts of terai, namely Nawalparasi, Bara, Parsa, Rautahat, Rupandehi, and Kapilvastu. In these districts, arsenic contamination in tubewells varied from 2.1% to 25.7%. The prevalence of arsenicosis was, on average, 2.2% and varied from 0.7% in Kapilavastu district to 3.6% in Nawalparasi district. In the community-based study, the highest prevalence (18.6%) of arsenicosis was found in Patkhouli village of Nawalparasi, where 95.8% of tubewells were contaminated with arsenic. The prevalence of arsenicosis was higher in older age-groups (>50 years) of both the sexes. Males suffered more from arsenicosis than females (odds ratio: 2.50, 95% confidence interval 1.80-3.47). Skin manifestations, such as melanosis and keratosis, were the common symptoms of arsenicosis. Most patients were identified in the early or mild stage of the disease. They are expected to recover if further exposure to arsenic could be avoided by providing arsenic-safe drinking-water through intervention measures.     

Health effects of exposure to natural arsenic in groundwater and coal in China: an overview of occurrence

Between 2001 and 2005, 21,155 of 445,638 wells in 20,517 villages in 292 counties in 16 provinces from China, or 5% of wells, were found to contain > 50 microg/L arsenic (As) by field testing with the Merck As kit. We achieved quality assurance of analysis of at least 10% of the wells containing > 50 microg/L As using hydride generation atomic fluorescence spectrometry and silver dithiodicarbomate spectrometry. Our best estimate of the population exposed to > 50 microg/L As in drinking water was 582,769. This is probably an underestimate for China because of the limited area surveyed. In a survey of 135,492 individuals in eight provinces, we used the National Diagnosis Standard for Endemic Arsenicosis and identified 10,096 cases of arsenicosis with various degrees of skin lesions. The arsenicosis occurrence rate of 7.5% is likely an overestimate, because the survey focused more on known and suspected endemic areas of arsenicosis. The occurrence of arsenicosis correlates positively with the percentage of wells containing > 50 microg/L As, or at a ratio of 1 to 5%. Based on both the amount of As in well water and the rate of occurrence of arsenicosis, Shanxi province, Inner Mongolia autonomous region, and Jilin province are the top three areas in China as of 2005 for exposure to endemic As from drinking water. Our survey also identified exposure to high levels of As from wells in several provinces and from the indoor burning of coal containing high levels of As in Shaanxi province. These areas, however, have not had any reports of previous arsenicosis endemics. In the endemic areas, the average rate of occurrence of arsenicosis at advanced stages was 1.2%, possibly because of a long exposure time of > 20 years; the rate of occurrence increased to 2.7% when we included a high dose of As exposure from the indoor burning of coal. Mitigation to reduce As exposure remains a challenge in rural China.     

Acute and chronic health effects due to green tobacco exposure in agricultural workers

BACKGROUND: An epidemiological study was undertaken in Gujarat, India to study the acute and chronic health effects of occupational exposure to green tobacco. METHODS: Non-Flue Cured Virginia (FCV) tobacco is the main crop in many districts of Central Gujarat. Three villages were selected from Anand district for the study and a random sample of 685 exposed workers were examined. Six hundred and fifty-five control workers with the same socio-economic status were examined from two villages where tobacco was not cultivated. RESULTS: The overall prevalence of green tobacco sickness (GTS) was 47.0% among tobacco workers. The prevalence in women workers was 55.7% while in men workers it was 42.66%. To detect the chronic health effects prevalence of hypertension, electrocardiogram (ECG) abnormalities, and eye problems in all the workers and reproductive abnormalities in women workers, all subjects received a medical examination. The data were compared in exposed and control group but they were non-significant statistically. No case of tobacco amblyopia was detected. CONCLUSION: The prevalence of GTS among non-FCV tobacco workers is high. However, from viewpoint of severity it can be considered as mild acute nicotine toxicity, which is relieved without medication. No significant difference is observed as regards to chronic health effects among tobacco workers and control workers.     

Factors Associated with Arsenicosis and Arsenic Exposure Status in Nepal: Implications from Community Based Study

A significant public health problem due to exposure to arsenic via groundwater in communities of lowland Terai region of Nepal has issued forth need to assess the exposure status and factors associated with arsenicosis. We observed arsenical dermal manifestations and collected and assessed total arsenic content in tubewell water, urine, and hair samples of study subjects at arsenic affected communities in Nawalparasi district of Nepal. The explanatory variables associated with arsenicosis were elevated arsenic in tubewell, male gender and increased age (P < 0.05). 67% (73/109) and 66% (77/117) of subjects exceeded the normal urinary and hair arsenic levels respectively. Among them 52% (57/109) and 47% (55/117) exceeded normal urinary and hair arsenic levels having no arsenical dermal manifestations. Males and symptomatic cases had significantly higher hair arsenic levels (P < 0.05). We also observed significant positive correlation of both urine and hair arsenic levels to tubewell arsenic levels (r = 0.27, 0.37, P < 0.01) and negative correlation of urine arsenic levels with the age of the subjects (r = −0.18, P = 0.06). We conclude that elucidating factors associated with arsenicosis could be of prime importance in intervention and preventive measures. In arsenic affected communities of Nepal exposure to arsenic is still a major problem despite mitigation efforts and the potential for sub-clinical effects in exposed population is high.     

Electrocardiographic abnormalities among arsenic-exposed persons through groundwater in Bangladesh

This study was carried out among arsenic-exposed and non-exposed people of Bangladesh to assess and compare their cardiac status based on electrocardiographic (ECG) findings. For the purpose of the study, participants were included in three groups: arsenic-exposed persons with arsenicosis (arsenicosis group), arsenic-exposed persons without arsenicosis (non-arsenicosis group), and persons not exposed to arsenic (non-exposed group). Each group included 50 respondents. In this study, no significant difference in heart rate, rhythm, axis, and pulse rate interval was detected among the arsenicosis, non-arsenicosis and non-exposed groups. A significant difference in corrected QT interval between the arsenicosis and the non-exposed group (p<0.05) was observed. On the contrary, no statistically significant difference in corrected QT interval between the non-arsenicosis and the non-exposed group was found. Abnormal QRS complex was found among 14%, 8%, and 2% of the arsenicosis, non-arsenicosis, and non-exposed groups respectively. ECG findings, indicative of left ventricular hypertrophy, ischaemic heart disease, and right bundle branch block, were high among the arsenicosis group. Overall, abnormal ECG findings were high (58%) among the respondents of the arsenicosis group and were highly significant (p<0.001). The findings revealed that there was a significant association between ECG abnormalities and arsenic exposure.     

Urinary Arsenic Speciation and its Correlation with 8-OHdG in Chinese Residents Exposed to Arsenic Through Coal Burning

In contrast to arsenicosis caused by consumption of water contaminated by naturally occurring inorganic arsenic, human exposure to this metalloid through coal burning has been rarely reported. In this study, arsenic speciation and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels in urine were determined in the Chinese residents exposed to arsenic through coal burning in Guizhou, China, an epidemic area of chronic arsenic poisoning caused by coal burning. The urinary concentrations of inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and total arsenic (tAs) of high-arsenic exposed subjects were significantly higher than those of low-arsenic exposed residents. A biomarker of oxidative DNA damage, urinary 8-OHdG level was significantly higher in high-arsenic exposed subjects than that of low exposed. Significant positive correlations were found between 8-OHdG levels and concentrations of iAs, MMA, DMA and tAs, respectively. In addition, a significant negative correlation was observed between 8-OHdG levels and the secondary methylation ratio (DMA/(MMA + DMA)). The results suggest that chronic arsenic exposure through burning coal rich in arsenic is associated with oxidative DNA damages, and that secondary methylation capacity is potentially related to the susceptibility of individuals to oxidative DNA damage induced by arsenic exposure through coal burning in domestic living.     

Fighting arsenic at the grassroots: experience of BRAC's community awareness initiative in Bangladesh

The study evaluates the arsenic mitigation project of BRAC in raising awareness of arsenic poisoning in rural communities in Bangladesh. Data came from selected project villages in south-western Bangladesh. Comparison villages were also selected from the same region. A total of 1240 randomly selected adults were interviewed in May 2000. Findings reveal that the mitigation project played a significant, positive role in raising awareness of the safe water options, signs of arsenicosis, mode of transmission and the type of treatment. Testing tube-well water for arsenic created curiosity, innovation and interest in the community, and the water treatment plant became a symbol of the arsenic campaign. The study concludes that the behavioural change aspects of the arsenic mitigation project have the potential to significantly improve the level of understanding about arsenic contamination in the traditional communities.     

Risk of internal cancers from arsenic in drinking water

The U.S. Environmental Protection Agency is under a congressional mandate to revise its current standard for arsenic in drinking water. We present a risk assessment for cancers of the bladder, liver, and lung from exposure to arsenic in water, based on data from 42 villages in an arseniasis-endemic region of Taiwan. We calculate excess lifetime risk estimates for several variations of the generalized linear model and for the multistage-Weibull model. Risk estimates are sensitive to the model choice, to whether or not a comparison population is used to define the unexposed disease mortality rates, and to whether the comparison population is all of Taiwan or just the southwestern region. Some factors that may affect risk could not be evaluated quantitatively: the ecologic nature of the data, the nutritional status of the study population, and the dietary intake of arsenic. Despite all of these sources of uncertainty, however, our analysis suggests that the current standard of 50 microg/L is associated with a substantial increased risk of cancer and is not sufficiently protective of public health.     

Determinants of arsenicosis patients' perception and social implications of arsenic poisoning through groundwater in Bangladesh

Adverse human health effects ranging from skin lesions to internal cancers as well as widespread social and psychological problems caused by arsenic contaminated drinking water in Bangladesh may be the biggest arsenic calamity in the world. From an arsenicosis patients survey, this paper empirically analyzes the determinants of arsenicosis patients' perception about chronic arsenic poisoning and social and psychological implications of arsenicosis. In this study, cross-sectional data were collected from the Matlab and Hajiganj Upzillas of Chandpur district which are known to be highly contaminated with arsenic in their underground water. Respondents informed that arsenic poisoning causes a wide range of social and psychological problems. Female respondents were less vulnerable in the case of social problems (p < 0.01) and more vulnerable for the psychological problems (p < 0.001) of arsenicosis than male respondents. The results based on logit analysis showed that education (p < 0.01) and household income (p < 0.05) were significantly correlated to respondents' perception about arsenicosis. The arsenicosis related special program (s) needs a clear understanding of people's perception about arsenic exposure for abating the health burden as well as social and psychological problems.     

Risk of arsenic-related skin lesions in Bangladeshi villages at relatively low exposure: a report from Gonoshasthaya Kendra

OBJECTIVE: Arsenic concentrations in 25% of tube wells in Bangladesh exceed 50 microg/L, a level known to be hazardous. Levels in individual wells vary widely. We gathered data on arsenic exposure levels and skin lesion prevalence to address the lack of knowledge about risks where the average arsenic concentrations was lower. METHODS: The nongovernmental organization Gonoshasthaya Kendra did three related studies of keratotic skin lesions since 2004: (1) an ecological prevalence survey among 13 705 women aged > 18 in a random sample of 53 villages; (2) a case-control study of 176 cases and age- and village-matched referents; and (3) a prevalence survey of the entire population of 11,670 in two additional villages. We calculated prevalence as a function of average arsenic concentrations as reported in the National Hydrochemical Survey, and measured arsenic concentrations in wells used by subjects in the case-control study. FINDINGS: The prevalence of skin lesions was 0.37% in people exposed to arsenic concentrations below 5 microg/L, 0.63% at 6-50 microg/L, and 6.84% at 81 microg/L. In the case-control analysis, relative risk of skin lesions increased threefold at concentrations above 50 microg/L (P < 0.05). CONCLUSION: Little serious skin disease is likely to occur if the arsenic concentration in drinking water is kept below 50 microg/L, but ensuring this water quality will require systematic surveillance and reliable testing of all wells, which may be impractical. More research is needed on feasible prevention of toxic effects from arsenic exposure in Bangladesh.