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1.
To evaluate the main intake source of arsenic by the villagers from arsenic-affected families in Jalangi and Domkol blocks in Mushidabad district, West Bengal-India, we determined the concentrations of arsenic in tube-well water and in food composites, mainly including vegetables and cereals collected from the surveyed families which were cultivated in that region. The daily dietary intakes of arsenic by the villagers were estimated and the excretions of arsenic through urine and hair were determined. The arsenic concentrations in hair and urine of the studied population living in mild (2.78 microg/L), moderate (30.7 microg/L) and high (118 microg/L) arsenic-affected families were 133, 1,391 and 4,713 microg/kg and 43.1, 244 and 336 microg/L, respectively. The linear regressions show good correlations between arsenic concentrations in water vs hair (r(2)=0.928, p<0.001) and water vs urine (r(2)=0.464, p<0.01). Approximately 29.4%, 58.1% and 62.1% of adult population from mild, moderate and high arsenic-affected families were suffering from arsenical skin manifestations. The mean arsenic concentrations of food composites (vegetables and cereals) in high arsenic-affected families are not significantly different from mild arsenic-affected families. The daily dietary intakes of arsenic from water and food composites of the studied population, living in high, moderate and mild arsenic-affected families were 568, 228 and 137 microg, respectively. The linear regressions show good correlations between arsenic concentrations in hair vs daily dietary intake (r(2)=0.452, p<0.001) and urine vs daily dietary intake (r(2)=0.134, p<0.001). The water for drinking contributed 6.07%, 26.7% and 58.1% of total arsenic in our study from mild, moderate and high arsenic-affected families. The result suggested that the contaminated water from high arsenic-affected families should be the main source for intake of arsenic. On contrary, the contribution of arsenic-contaminated food composites from mild and moderate arsenic-affected families might be the main source for intake of arsenic. The Food and Agriculture Organization/World Health Organization (FAO/WHO) provisional tolerable weekly intake (PTWI) values of arsenic in our study were 3.32, 5.75 and 12.9 microg/kg body weight/day from mild, moderate and high arsenic-affected families, respectively, which is higher than the recommended PTWI value of arsenic (2.1 microg/kg body weight/day).  相似文献   

2.
Sixty-four arsenic (As) resistant bacteria isolated from an arsenic rich groundwater sample of West Bengal were characterized to investigate their potential role in subsurface arsenic mobilization. Among the isolated strains predominance of genera Agrobacterium/Rhizobium, Ochrobactrum and Achromobacter which could grow chemolitrophically and utilize arsenic as electron donor were detected. Higher tolerance to As3+ [maximum tolerable concentration (MTC): ≥10 mM], As5+ (MTC: ≥100 mM) and other heavy metals like Cu2+, Cr2+, Ni2+ etc. (MTC: ≥10 mM), presence of arsenate reductase and siderophore was frequently observed among the isolates. Ability to produce arsenite oxidase and phosphatase enzyme was detected in 50 and 34 % of the isolates, respectively. Although no direct correlation among taxonomic identity of bacterial strains and their metabolic abilities as mentioned above was apparent, several isolates affiliated to genera Ochrobactrum, Achromobacter and unclassified Rhizobiaceae members were found to be highly resistant to As3+ and As5+ and positive for all the test properties. Arsenate reductase activity was found to be conferred by arsC gene, which in many strains was coupled with arsenite efflux gene arsB as well. Phylogenetic incongruence between the 16S rRNA and ars genes lineages indicated possible incidence of horizontal gene transfer for ars genes. Based on the results we propose that under the prevailing low nutrient condition inhabitant bacteria capable of using inorganic electron donors play a synergistic role wherein siderophores and phosphatase activities facilitate the release of sediment bound As5+, which is subsequently reduced by arsenate reductase resulting into the mobilization of As3+ in groundwater.  相似文献   

3.
A speciation technique for arsenic has been developed using an anion-exchange high-performance liquid chromatography/inductively coupled argon plasma mass spectrometer (HPLC/ICP MS). Under optimized conditions, eight arsenic species [arsenocholine, arsenobetaine, dimethylarsinic acid (DMA(V)), dimethylarsinous acid (DMA(III)), monomethylarsonic acid (MMA(V)), monomethylarsonous acid (MMA(III)), arsenite (As(III)), and arsenate (As(V))] can be separated with isocratic elution within 10 min. The detection limit of arsenic compounds was 0.14-0.33 microg/L. To validate the method, Standard Reference Material in freeze-dried urine, SRM-2670, containing both normal and elevated levels of arsenic was analyzed. The method was applied to determine arsenic species in urine samples from three arsenic-affected districts of West Bengal, India. Both DMA(III) and MMA(III) were detected directly (i.e., without any prechemical treatment) for the first time in the urine of some humans exposed to inorganic arsenic through their drinking water. Of 428 subjects, MMA(III) was found in 48% and DMA(III) in 72%. Our results indicate the following. (1) Since MMA(III) and DMA(III) are more toxic than inorganic arsenic, it is essential to re-evaluate the hypothesis that methylation is the detoxification pathway for inorganic arsenic. (2) Since MMA(V) reductase with glutathione (GSH) is responsible for conversion of MMA(V) to MMA(III) in vivo, is DMA(V) reductase with GSH responsible for conversion of DMA(V) to DMA(III) in vivo? (3) Since DMA(III) forms iron-dependent reactive oxygen species (ROS) which causes DNA damage in vivo, DMA(III) may be responsible for arsenic carcinogenesis in human.  相似文献   

4.
Fifty districts of Bangladesh and 9 districts in West Bengal, India have arsenic levels in groundwater above the World Health Organization's maximum permissible limit of 50 microg/L. The area and population of 50 districts of Bangladesh and 9 districts in West Bengal are 118,849 km2 and 104.9 million and 38,865 km2 and 42.7 million, respectively. Our current data show arsenic levels above 50 microg/ L in 2000 villages, 178 police stations of 50 affected districts in Bangladesh and 2600 villages, 74 police stations/blocks of 9 affected districts in West Bengal. We have so far analyzed 34,000 and 101,934 hand tube-well water samples from Bangladesh and West Bengal respectively by FI-HG-AAS of which 56% and 52%, respectively, contained arsenic above 10 microg/L and 37% and 25% arsenic above 50 microg/L. In our preliminary study 18,000 persons in Bangladesh and 86,000 persons in West Bengal were clinically examined in arsenic-affected districts. Of them, 3695 (20.6% including 6.11% children) in Bangladesh and 8500 (9.8% including 1.7% children) in West Bengal had arsenical dermatological features. Symptoms of chronic arsenic toxicity developed insidiously after 6 months to 2 years or more of exposure. The time of onset depends on the concentration of arsenic in the drinking water, volume of intake, and the health and nutritional status of individuals. Major dermatological signs are diffuse or spotted melanosis, leucomelanosis, and keratosis. Chronic arsenicosis is a multisystem disorder. Apart from generalized weakness, appetite and weight loss, and anemia, our patients had symptoms relating to involvement of the lungs, gastrointestinal system, liver, spleen, genitourinary system, hemopoietic system, eyes, nervous system, and cardiovascular system. We found evidence of arsenic neuropathy in 37.3% (154 of 413 cases) in one group and 86.8% (33 of 38 cases) in another. Most of these cases had mild and predominantly sensory neuropathy. Central nervous system involvement was evident with and without neuropathy. Electrodiagnostic studies proved helpful for the diagnosis of neurological involvement. Advanced neglected cases with many years of exposure presented with cancer of skin and of the lung, liver, kidney, and bladder. The diagnosis of subclinical arsenicosis was made in 83%, 93%, and 95% of hair, nail and urine samples, respectively, in Bangladesh; and 57%, 83%, and 89% of hair, nail, and urine samples, respectively in West Bengal. Approximately 90% of children below 11 years of age living in the affected areas show hair and nail arsenic above the normal level. Children appear to have a higher body burden than adults despite fewer dermatological manifestations. Limited trials of 4 arsenic chelators in the treatment of chronic arsenic toxicity in West Bengal over the last 2 decades do not provide any clinical, biochemical, or histopathological benefit except for the accompanying preliminary report of clinical benefit with dimercaptopropanesulfonate therapy. Extensive efforts are needed in both countries to combat the arsenic crisis including control of tube-wells, watershed management with effective use of the prodigious supplies of surface water, traditional water management, public awareness programs, and education concerning the apparent benefits of optimal nutrition.  相似文献   

5.
Assessment of DNA damage was carried out using alkaline comet assay in lymphocytes of 30 individuals exposed to high levels of arsenic (247.12+/-18.93 microg/l) through contaminated groundwater in North 24 Parganas district, West Bengal, India. All of them exhibited high arsenic contents in nail (4.20+/-0.67 microg/g), hair (2.06+/-0.20 microg/g) and urine (259.75+/-33.89 microg/l) samples and manifested various arsenical skin lesions. Unexposed samples were collected from 30 residents of the unaffected East Midnapur district with very little or no exposure to arsenic (7.69+/-0.49 microg/l) in drinking water. The results were evaluated principally by manual analysis of comets and partly by computerized image analysis. Both the analytical methods exhibited a high degree of agreement in results. The exposed participants expressed significantly higher DNA damage (p < 0.01) in their lymphocytes than the unexposed participants. Alkaline comet assay was also combined with formamidopyrimidine-DNA glycosylase enzyme digestion to confirm that arsenic induced oxidative base damage in the lymphocytes. Significant positive trend effects of comet lengths in relation to arsenic levels in water prove that DNA damage can be used as a sensitive biomarker of arsenic exposure. This study demonstrates that arsenic induced significant DNA damage in the exposed participants, which could correspond to a higher susceptibility to arsenic induced toxicity and carcinogenicity.  相似文献   

6.
Nail and hair are rich in fibrous proteins, i.e., alpha-keratins that contain abundant cysteine residues (up to 22% in nail and 10-14% in hair). Although they are metabolically dead materials in the epidermis, the roots are highly influenced by the health status of the living beings and their analyses are used as a tool to monitor occupational and environmental exposure to toxic elements. The aims of the present study are to speciate arsenicals in human nail and hair and also to judge whether they should be used as a biomarker to arsenic (As) exposure and/or toxicity. All human fingernail and hair samples (n = 47) were collected from the As-affected area of West Bengal, India. Speciation of arsenicals in water extracts of fingernails and hair at 90 degrees C was carried out by HPLC-inductively coupled argon plasma mass spectrometer (ICP MS). Fingernails contained iAs(III) (58.6%), iAs(V) (21.5), MMA(V) (7.7), DMA(III) (9.2), and DMA(V) (3.0), and hair contained iAs(III) (60.9%), iAs(V) (33.2), MMA(V) (2.2), and DMA(V) (3.6). Fingernails contained DMA(III), but hair did not. The higher percentage of iAs(III) both in fingernails and hair than that of iAs(V) suggests more affinity of iAs(III) to keratin. Although all arsenicals in fingernails and hair correlate to As exposure positively, As speciation in fingernails seems to be more correlated with arsenism than that in hair. Exogenous contamination is a confounding factor for hair to consider it as a biomarker, whereas this is mostly absent in fingernails, which recommends it to be a better biomarker to arsenic exposure. DMA(III) content in fingernails and DMA(V) contents in both fingernails and hair could be the biomarker to As exposure.  相似文献   

7.

Context:

Visceral leishmaniasis (VL), also known as Kala-azar (KA) is a public health problem of tropical and subtropical countries, which infects about 12 million people annually, out of which about 1.5 million are new cases. India contributes a major share of the global burden of VL. For many years leishmaniasis has been treated with pentavalent antimonials. Antimony resistance is a problem in India and in other different geographic areas of the world. Amphotericin B deoxycholate and pentamidine isethionate are effective by parenteral administration and associated with toxicities. The quest for an effective, orally administered, non-toxic and less expensive alternative resulted in the identification of miltefosine (hexadecylphosphocholine). In India, therapeutic efficacy of miltefosine in VL was assessed by many groups of scientists, mainly from Bihar and Uttar Pradesh. No such data is available from West Bengal.

Aims:

The present study was designed to observe the efficacy of miltefosine in VL in rural West Bengal.

Materials and Methods:

A total of 71 parasitologically proven VL patients participated in the study who received miltefosine in accordance with the National Vector Born Disease Control Programme (NVBDCP) of India and were followed up for the following one year.

Results:

The overall efficacy of the drug was 93% and no significant adverse side effects were observed during the study period.

Conclusions:

The study concludes that miltefosine is effective, well tolerated, and easily administrable drug in the treatment of visceral leishmaniasis at the field levels.KEY WORDS: India, visceral leishmaniasis, miltefosine  相似文献   

8.
9.
10.
The objective of the study was to assess the status of iodine nutrition in an area of Howrah district where iodine deficiency disorders (IDD) were reported despite the introduction of iodised salt for general use. A total of 969 school children in the age group 6-12 years of both sexes were clinically examined for goitre. On the spot 242 urine samples were collected from the children to study the iodine and thiocyanate excretion pattern and 108 edible salt samples were collected from the homes of the children to measure iodine level. Drinking water samples were collected to evaluate the bioavailability of iodine in the region. The total goitre prevalence was 37.6% (Grade 1: 32.6%; Grade 2: 4.9%). The median urinary iodine level was 35 microg/dL, 12.5% urine samples had iodine level below 10 microg/dL and no sample was found to contain iodine below 5 microg/dL. In 51.9% salt samples iodine level was below 15 ppm and the iodine level in the drinking water was about 82 microg/L. The people of the area consume foods from the vegetables of the Brassica family and mean thiocyanate level was 0.747+/-0.21 mg/dL. The-findings of the present study indicated that as per clinical criteria of WHO/UNICEF/ICCIDD, IDD is a severe public health problem though apparently there is no biochemical iodine deficiency. Overall results indicate that factors other than iodine deficiency may have a role in the persistence of endemic goitre in the post salt-iodisation in this region.  相似文献   

11.
A market basket survey of inorganic arsenic in food.   总被引:12,自引:0,他引:12  
Dietary arsenic intake estimates based on surveys of total arsenic concentrations appear to be dominated by intake of the relatively non-toxic, organic arsenic forms found in seafood. Concentrations of inorganic arsenic in food have not been not well characterized. Accurate dietary intake estimates for inorganic arsenic are needed to support studies of arsenic's status as an essential nutrient, and to establish background levels of exposure to inorganic arsenic. In the market basket survey reported here, 40 commodities anticipated to provide at least 90% of dietary inorganic arsenic intake were identified. Four samples of each commodity were collected. Total arsenic was analysed using an NaOH digestion and inductively coupled plasma-mass spectrometry. Separate aliquots were analysed for arsenic species using an HCl digestion and hydride atomic absorption spectroscopy. Consistent with earlier studies, total arsenic concentrations (all concentrations reported as elemental arsenic per tissue wet weight) were highest in the seafoods sampled (ranging from 160 ng/g in freshwater fish to 2360 ng/g in saltwater fish). In contrast, average inorganic arsenic in seafood ranged from less than 1 ng/g to 2 ng/g. The highest inorganic arsenic values were found in raw rice (74 ng/g), followed by flour (11 ng/g), grape juice (9 ng/g) and cooked spinach (6 ng/g). Thus, grains and produce are expected to be significant contributors to dietary inorganic arsenic intake.  相似文献   

12.
Survey of 611 streptomycetes isolates from 330 soil samples from various parts of West Bengal were done for their antimicrobial activity against Gram positive, Gram negative bacteria, unicellular and filamentous fungi. The strain 321.2 showed inhibition against all the test organisms used and found as potent. The morphological, cultural, physiological and biochemical characters were studied, compared with known species and identified as Streptomyces albidoflavus. This strain produces an antibiotic.  相似文献   

13.
14.
A study was conducted in June 2004 to find out the epidemiology of HIV infection among injecting drug users (IDUs) of Darjeeling District of West Bengal, eastern India. The district headquarter, Darjeeling town, also known as “Queen of Hills,” is a beautiful spot situated in Himalayan West Bengal that attracts a large number of tourists each year from all over the world. Another unique feature of the district is that it has international boundaries with three countries, Nepal, Bhutan, and Bangladesh. Siliguri, the part of the district on plains, acts as a transit station for these countries as well as to the entire Himalayan region of West Bengal and neighboring state, Sikkim. It is also a transit point to all northeastern states of India: Assam, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Meghalaya, and Tripura. Two hundred twenty-eight study subjects (IDUs) were included in this community-based cross-sectional study from all four subdivisions of the district. Informed consent was obtained, and then personal interviews, followed by blood testing were performed using unlinked anonymous procedure. The study revealed that overall HIV seroprevalence among IDUs was 11.8% (n = 27; 95% confidence interval, 7.9–16.7), whereas seroprevalence of hepatitis C was found to be 47.7% (n = 97). Prevalence of HIV was higher in subjects from hill districts (13.5%) compared with subjects from the plains (9.2%). It also revealed that most IDUs (75.3%) used “brown sugar,” an impure form of heroin, as their major addictive substance followed by injection norphine. Sharing of injecting equipment was found to be as high as 67% among IDUs, and sharing of drugs from common ampules was found to be 35.5% of the studied subjects (n = 93). Most subjects (96%) were found to clean their injecting paraphernalia with plain water. Most IDUs (98%) were found to inject intravenously. About 52% of IDUs visited sex workers one or more times within the last 1 year, and 15% of the interviewed subjects (n = 93) reported to suffer from sexually transmitted diseases during the same period. All the IDUs knew about HIV/AIDS. About 69% of the subjects knew that apparently healthy looking person might have HIV infection. HIV was found to be associated significantly with age of the injectors and duration of injecting practices. The study revealed the epidemic of HIV and hepatitis C among IDU populations at this bordering district of West Bengal for the first time that requires urgent intervention at local, national, and international levels.  相似文献   

15.
A study was conducted in June 2004 to find out the epidemiology of HIV infection among injecting drug users (IDUs) of Darjeeling District of West Bengal, eastern India. The district headquarter, Darjeeling town, also known as "Queen of Hills," is a beautiful spot situated in Himalayan West Bengal that attracts a large number of tourists each year from all over the world. Another unique feature of the district is that it has international boundaries with three countries, Nepal, Bhutan, and Bangladesh. Siliguri, the part of the district on plains, acts as a transit station for these countries as well as to the entire Himalayan region of West Bengal and neighboring state, Sikkim. It is also a transit point to all northeastern states of India: Assam, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Meghalaya, and Tripura. Two hundred twenty-eight study subjects (IDUs) were included in this community-based cross-sectional study from all four subdivisions of the district. Informed consent was obtained, and then personal interviews, followed by blood testing were performed using unlinked anonymous procedure. The study revealed that overall HIV seroprevalence among IDUs was 11.8% (n = 27; 95% confidence interval, 7.9-16.7), whereas seroprevalence of hepatitis C was found to be 47.7% (n = 97). Prevalence of HIV was higher in subjects from hill districts (13.5%) compared with subjects from the plains (9.2%). It also revealed that most IDUs (75.3%) used "brown sugar," an impure form of heroin, as their major addictive substance followed by injection norphine. Sharing of injecting equipment was found to be as high as 67% among IDUs, and sharing of drugs from common ampules was found to be 35.5% of the studied subjects (n = 93). Most subjects (96%) were found to clean their injecting paraphernalia with plain water. Most IDUs (98%) were found to inject intravenously. About 52% of IDUs visited sex workers one or more times within the last 1 year, and 15% of the interviewed subjects (n = 93) reported to suffer from sexually transmitted diseases during the same period. All the IDUs knew about HIV/AIDS. About 69% of the subjects knew that apparently healthy looking person might have HIV infection. HIV was found to be associated significantly with age of the injectors and duration of injecting practices. The study revealed the epidemic of HIV and hepatitis C among IDU populations at this bordering district of West Bengal for the first time that requires urgent intervention at local, national, and international levels.  相似文献   

16.
Effect of thermal treatments on arsenic species contents in food.   总被引:3,自引:0,他引:3  
In arsenic-endemic and other areas, food is an important path of exposure to this contaminant. Food is generally consumed in processed form, after a preservation treatment or cooking, which may alter the concentrations and chemical forms of arsenic. This article summarizes and discusses the work so far published on the effect that thermal treatment used in the cooking or processing of food, including sterilization and preservation stages, has on total arsenic and arsenic species contents. It also reviews possible transformations in arsenic species. The studies included use model systems or food products of marine or vegetable origin. Processing may cause a considerable increase or decrease in the real arsenic intake from food. For example, traditional washing and soaking of Hizikia fusiforme seaweed, which has very high inorganic arsenic contents, may reduce the contents by up to 60%. On the other hand, all the arsenic present in cooking water may be retained during boiling of rice, increasing the contents of this metalloid to significant levels from a toxicological viewpoint. This calls for modifications in arsenic risk assessment, hitherto based on analysis of the raw product. It is necessary to consider the effect of processing on total arsenic and arsenical species in order to obtain a realistic view of the risk associated with intake in arsenic-endemic and other areas.  相似文献   

17.
8-Hydroxydeoxyguanosine (8-OHdG) is one of the most reliable and abundant markers of DNA damage. The study was designed to explore the relationship between urinary 8-OHdG and renal cell carcinoma (RCC) and to investigate whether individuals with a high level of 8-OHdG would have a modified odds ratio (OR) of arsenic-related RCC. This case-control study was conducted with 132 RCC patients and 245 age- and sex-matched controls from a hospital-based pool between November 2006 and May 2009. Pathological verification of RCC was completed by image-guided biopsy or surgical resection of renal tumors. Urinary 8-OHdG levels were determined using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Concentrations of urinary arsenic species, including inorganic arsenic, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), were determined by a high performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. Level of urinary 8-OHdG was significantly associated with the OR of RCC in a dose-response relationship after multivariate adjustment. Urinary 8-OHdG was significantly related to urinary total arsenic. The greatest OR (3.50) was seen in the individuals with high urinary 8-OHdG and high urinary total arsenic. A trend test indicated that the OR of RCC was increased with one of these factors and was further increased with both (p = 0.002). In conclusion, higher urinary 8-OHdG was a strong predictor of the RCC. High levels of 8-OHdG combined with urinary total arsenic might be indicative of arsenic-induced RCC.  相似文献   

18.
Arsenic is a potent environmental toxicant causing serious public health concerns in India, Bangladesh and other parts of the world. Gene- and promoter-specific hypermethylation has been reported in different arsenic-exposed cell lines, whereas whole genome DNA methylation study suggested genomic hypo- and hypermethylation after arsenic exposure in in vitro and in vivo studies. Along with other characteristic biomarkers, arsenic toxicity leads to typical skin lesions. The present study demonstrates significant correlation between severities of skin manifestations with their whole genome DNA methylation status as well as with a particular polymorphism (Ala 140 Asp) status in arsenic metabolizing enzyme Glutathione S-transferase Omega-1 (GSTO1) in arsenic-exposed population of the district of Nadia, West Bengal, India.  相似文献   

19.
A procedure for the speciation of arsenic(III) and arsenic(V) in natural water samples has been established in the presented work. Arsenic(III) ions were quantitatively recovered on Alternaria solani coated Diaion HP-2MG resin at pH 7, while the recoveries of arsenic(V) was below 10%. Arsenic(V) in the mixing solution containing As(III) and As(V) was reduced by using KI and L(+) ascorbic acid solution, then the procedure was applied to determination of total arsenic. Arsenic(V) was calculated as the difference between the total arsenic content and As(III) content. The determination of arsenic was performed by using hydride generation atomic absorption spectrometry. The influences of some alkali, earth alkali and transition metals on the biosorption of arsenic(III) were investigated. The preconcentration factor was 35. The detection limits for As(III) (N = 20, k = 3) was found as 11 ng L−1. The relative standard deviation and relative error of the determinations were found to be lower than 7% and 4%, respectively. The accuracy of the method was confirmed with certified reference materials. The method was successively applied for the determination and speciation of inorganic arsenic in water, food and biological samples.  相似文献   

20.
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