Significance of the prime factors regulating arsenic toxicity and associated health risk: a hypothesis-based investigation in a critically exposed population of West Bengal, India.

The suffering from arsenic toxicity is a long-standing concern in Asian countries. The role of the key factors (arsenic intake, age and sex) regulating arsenic toxicity is aimed to evaluate for a severely exposed population from Murshidabad district, West Bengal. Mean arsenic concentrations in drinking water supplied through tube well, Sajaldhara treatment plant and pipeline were observed as 208, 27 and 54 µg/l, respectively. Urinary arsenic concentration had been observed as < 3-42.1, < 3-56.2 and < 3-80 µg/l in children, teenagers and adults, respectively. Mean concentrations of hair and nail arsenic were found to be 0.84 and 2.38 mg/kg; 3.07 and 6.18 mg/kg; and 4.41 and 9.07 mg/kg, respectively, for the studied age-groups. Water arsenic was found to be associated with hair and nail (r = 0.57 and 0.60), higher than urine (r = 0.37). Arsenic deposition in biomarkers appeared to be dependent on age; however, it is independent of sex. Principal component analysis showed a direct relationship between dietary intake of arsenic and chronic biomarkers. Nail was proved as the most fitted biomarker of arsenic toxicity by Dunn's post hoc test. Monte Carlo sensitivity analysis and cluster analysis showed that the most significant factor regulating health risk is 'concentration of arsenic' than 'exposure duration', 'body weight' and 'intake rate'. The contribution of arsenic concentration towards calculated health risk was highest in teenagers (45.5-61.2%), followed by adults (47.8-49%) and children (21-27.6%). Regular and sufficient access to arsenic-safe drinking water is an immediate need for the affected population.

Possible Association Between Polymorphisms in ESR1, COL1A2, BGLAP, SPARC, VDR, and MMP2 Genes and Dental Fluorosis in a Population from an Endemic Region of West Bengal.

Dental fluorosis (DF) is the most prevalent form of fluorosis in India affecting millions of people all over the country. As estrogen receptor 1 (ESR1), collagen type 1 alpha 2 (COL1A2), bone γ-carboxyglutamic acid protein (BGLAP), secreted protein acidic and cysteine-rich (SPARC), vitamin D receptor (VDR), and matrix metallopeptidase 2 (MMP2) genes play critical roles in bone metabolism, bone formation, mineral metabolism, and mineralization, variants in these genes could influence susceptibility to DF. The present study was aimed at evaluating the association between 15 single-nucleotide polymorphisms (SNPs) in the six candidate genes (namely, ESR1, COL1A2, BGLAP, SPARC, VDR, and MMP2) and DF among 132 individuals (case = 71 and control = 61) living in a fluoride endemic region of West Bengal, India. No statistically significant association with disease risk was found when the genotypes and allele frequencies of each of the 15 SNPs was analyzed individually using odd's ratio with 95% confidence interval. "CC" and "AG" haplotypes of the COL1A2 gene showed a borderline association with DF. The present study is the first in India to use multifactor dimensionality reduction (MDR) analysis for identifying gene-gene and gene-environment interactions in fluorosis. The biomarker of serum fluoride showed a significant association with the disease state among the 17 attributes (15 SNPs and 2 biomarkers of urine fluoride and serum fluoride) (P value = 0.011). The best model of MDR analysis with maximized testing accuracy involved two SNPs from the ESR1 gene (rs9340799 and rs2077647) and one SNP from BGLAP gene (rs1543294) (P value < 0.0001).

Arsenic exposure from drinking water and staple food (rice): A field scale study in rural Bengal for assessment of human health risk.

Arsenic is a well-known carcinogen with emerging reports showing a range of health outcomes even for low to moderate levels of exposure. This study deals with arsenic exposure and associated increased lifetime cancer risk for populations in arsenic-endemic regions of rural Bengal, where arsenic-safe drinking water is being supplied at present. We found a median total exposure of inorganic arsenic to be 2. 9 µg/Kg BW/day (5th and 95th percentiles were 1.1 µg/Kg BW/day and 7.9 µg/Kg BW/day); with major contribution from cooked rice intake (2.4 µg/Kg BW/day). A significant number of households drank arsenic safe water but used arsenic-rich water for rice cooking. As a result, 67% participants had inorganic arsenic intake above the JEFCA threshold value of 3 µg/Kg BW/day for cancer risk from only rice consumption when arsenic contaminated water was used for cooking (median: 3.5 µg/Kg BW/day) compared to 29% participants that relied on arsenic-free cooking water (median: 1.0 µg/kg BW/day). Arsenic in urine samples of study participants ranged from 31.7 to 520 µg/L and was significantly associated with the arsenic intake (r = 0.76); confirming the preponderance of arsenic exposure from cooked rice. The median arsenic attributable cancer risks from drinking water and cooked rice were estimated to be 2.4 × 10-5 and 2.7 × 10-4 respectively, which further emphasized the importance of arsenic exposure from staple diet. Our results show that any mitigation strategy should include both drinking water and local staple foods in order to minimize the potential health risks of arsenic exposure.

Health effect and risk assessment of the populations exposed to different arsenic levels in drinking water and foodstuffs from four villages in arsenic endemic Gaighata block, West Bengal, India.

Health exposure and perception of risk assessment have been evaluated on the populations exposed to different arsenic levels in drinking water (615, 301, 48, 20 µg/l), rice grain (792, 487, 588, 569 µg/kg) and vegetables (283, 187, 238, 300 µg/kg) from four villages in arsenic endemic Gaighata block, West Bengal. Dietary arsenic intake rates for the studied populations from extremely highly, highly, moderately, and mild arsenic-exposed areas were 56.03, 28.73, 11.30, and 9.13 µg/kg bw/day, respectively. Acute and chronic effects of arsenic toxicity were observed in ascending order from mild to extremely highly exposed populations. Statistical interpretation using 'ANOVA' proves a significant relationship between drinking water and biomarkers, whereas "two-tailed paired t test" justifies that the consumption of arsenic-contaminated dietary intakes is the considerable pathway of health risk exposure. According to the risk thermometer (SAMOE), drinking water belongs to risk class 5 (extremely highly and highly exposed area) and 4 (moderately and mild exposed area) category, whereas rice grain and vegetables belong to risk class 5 and 4, respectively, for all the differently exposed populations. The carcinogenic (ILCR) and non-carcinogenic risks (HQ) through dietary intakes for adults were much higher than the recommended threshold level, compared to the children. Supplementation of arsenic-safe drinking water and nutritional food is strictly recommended to overcome the severe arsenic crisis.

Evaluating the Association Between Dental Fluorosis and Polymorphisms in Bone Development and Mineralization Genes Among Population from a Fluoride Endemic Region of Eastern India.

Close to 12 million people in India are affected by more than the desirable level of fluoride in drinking water that could lead to dental, skeletal, and non-skeletal fluorosis. Dental fluorosis is a developmental defect that results in hypo-mineralization and pronounced porosity of enamel in the affected individuals. As estrogen receptor 1 (ESR1), collagen type 1 alpha 2 (COL1A2), bone γ-carboxyglutamic acid protein (BGLAP), and secreted protein acidic and cysteine rich (SPARC) genes are involved in bone development and mineralization, polymorphisms in these genes could be determining factors in influencing the risk to fluorosis among the exposed individuals in fluoride endemic areas. A case-control study was carried out among a total of 87 individuals (case = 36, control = 51) to examine the association between selected polymorphisms in the ESR1, COL1A2, BGLAP, and SPARC genes and risk of dental fluorosis from a fluoride endemic region of Eastern India. Altogether, 10 single nucleotide polymorphisms (SNPs) in ESR1 (rs2234693, rs2228480, rs3798577, rs2077647, and rs9340799), COL1A2 (rs42524, rs412777), BGLAP (rs1800247), and SPARC (rs6579885, rs4958278) genes were genotyped through PCR-RFLP in these subjects. The association of the SNPs for disease risk estimation was measured by odds ratio with 95% confidence interval. The risk genotypes of none of the 10 SNPs showed statistically significant association with risk of dental fluorosis. Frequencies of the haplotypes in the intragenic SNPs of the ESR1, COL1A2, and SPARC genes did not reveal any statistically significant difference between the case and control groups. The present study is the first of its kind from India that has attempted to investigate possible involvement of genetic factors in influencing the risk to fluorosis among the population from a fluoride endemic region.

Role of folic Acid on symptoms of chronic arsenic toxicity.

BACKGROUND: Chronic arsenic toxicity (Arsenicosis) due to drinking of arsenic contaminated ground water is a global problem. However, its treatment is unsatisfactory. Methylation of arsenic facilitates its urinary excretion. Persons with relatively lower proportion of urinary dimethyl arsenic acid (DMA) are found to have at greater risk of developing symptoms of arsenicosis including its complications. The biochemical pathway responsible for methylation of arsenic is a folate-dependent pathway. Studies in rodents and humans suggest that folate nutritional status influences the metabolism of arsenic. METHODS: The present study compares the effect of giving folic acid on 32 arsenicosis patients during a 6-month period and comparing the results with clinical effect of taking only arsenic-free safe water on 45 age and sex-matched arsenic-affected people for the same period. RESULTS: There was significant improvement of arsenical skin lesion score of both patients treated with folic acid (2.96 ± 1.46 to 1.90 ± 0.90, P < 0.001) and arsenic free safe water (2.91 ± 1.26 to 1.62 ± 1.05, P < 0.001) for a period of 6 months. Significant improvement in systemic disease score was also observed from the baseline systemic score in folic acid treated group (4.78 ± 3.43 to 1.00 ± 1.56, P < 0.001) and the group treated with arsenic-free water (1.87 ± 2.11 to 0.82 ± 1.62, P < 0.001). However, there was a significant increased improvement of systematic disease score in the folic acid treated group compared to the control group taking arsenic free water (P < 0.001). CONCLUSIONS: This study provides evidence that folic acid treatment in arsenicosis cases could help in reducing clinical symptoms of arsenicosis.

Evaluation of dietary arsenic exposure and its biomarkers: a case study of West Bengal, India.

Few reports are available that characterize daily arsenic exposure through water and diet among people living in groundwater-contaminated regions and correlate it with biomarkers. The present study describes the total individual arsenic exposure and arsenic level in urine and hair of such an arsenic-exposed population in West Bengal. Demographic characteristics and the total daily arsenic intake through water and diet were determined in 167 (Group-1 participants selected from arsenic endemic region) and 69 (Group-2 participants selected from arsenic non-endemic region) in West Bengal. Out of 167 Group-1 participants 78 (Group-1A) had arsenical skin lesions while 89 Group-1B) had no such lesion. Arsenic level in water samples as well as diet, urine and hair samples, collected from all the individual participants, were estimated. The mean value of estimated total arsenic content from water and diet was 349 (range: 20-1615) µg/day in 167 (Group-1) participants living in As endemic region [As in water: mean value 54 (range:BDL-326) µg/L] and 36 (range:12-120) µg/day in 69 (Group-2) participants living in As non-endemic region (As in water: below detection level (BDL), < 0.3 µg/L). Estimated mean arsenic level in urine in these two groups of participants was 116 (range: 6-526) µg/L and 17 (range: BDL-37) µg/L and in hair was 1.0 (range: 0.22-3.98) mg/Kg and 0.16 (range: 0.06-0.37) mg/Kg, respectively. Multiple regressions analysis in Group-1 participants showed that total arsenic intake was associated significantly with urinary and hair arsenic level. The estimated regression coefficient was 0.0022 (95% confidence interval, C.I: 0.0016, 0.0028; P < 0.001) and 0.0024 (95% C.I: 0.0021, 0.003; P < 0.001), respectively. In sub group analysis, higher median urinary arsenic value relative to arsenic intake through water and diet was observed in 78 Group-1A subjects with skin lesion compared to urinary arsenic value in 89 Group-1B subjects without skin lesions, though there was a marginal difference of median total arsenic intake in these two groups. This study showed that significant elevation of arsenic level in urine and hair was associated with elevated arsenic intake through water and diet in people living in arsenic endemic region (Group-1), while these values were low in people living in non-endemic region (Group-2). Those with skin lesions were found to have higher arsenic in urine and hair compared to those without skin lesion with similar arsenic intake through water and diet.

A study on prevalence of bacteria in the hands of children and their perception on hand washing in two schools of Bangalore and Kolkata.

BACKGROUND: Contaminated hands play a major role in fecal-oral transmission of diseases. In 1847, Dr Semmelweis Ignac pointed to the link between infection and unclean hands, and demonstrated that washing hands could reduce transmission of puerperal fever (child birth fever), a dreaded disease with high mortality in those days. MATERIALS AND METHODS: A cross-sectional study was conducted to find out the extent of germs present in hand, and also the students' perception on hand washing. This was assessed by questionnaire as well as by collection of swab from hand and performing bacteriological culture in the laboratory. RESULTS: In regard to students' perception about the dirty areas of the hands, it was observed that majority (78%) felt palm was likely to be more dirty while less than 70% felt that web spaces could harbor dirt. Almost 86% reported that they washed hands before eating lunch, but only 21.3% said they always used soap while 47.3% never used it. Availability of soap all the time in the school was reported by only 18.4% students. The swabs of 61% children showed potential pathogens. The commonest of these was Staphylococcus aureus which was seen in 44% samples. CONCLUSION: The students' hands were contaminated before taking food. Although they washed hands before meals, they hardly used soap due to non-availability of soap. The school authority should be asked to keep soaps in the toilets for hand washing.

Health impact of supplying safe drinking water containing fluoride below permissible level on flourosis patients in a fluoride-endemic rural area of West Bengal.

BACKGROUND: The problem of high fluoride concentration in groundwater resources has become one of the most important toxicological and geo-environmental issues in India. Excessive fluoride in drinking water causes dental and skeletal fluorosis, which is encountered in endemic proportions in several parts of the world. World Health Organization (WHO) guideline value and the permissible limit of fluoride as per Bureau of Indian Standard (BIS) is 1.5 mg/L. About 20 states of India, including 43 blocks of seven districts of West Bengal, were identified as endemic for fluorosis and about 66 million people in these regions are at risk of fluoride contamination. Studies showed that withdrawal of sources identified for fluoride often leads reduction of fluoride in the body fluids (re-testing urine and serum after a week or 10 days) and results in the disappearance of non-skeletal fluorosis within a short duration of 10-15 days. OBJECTIVE: To determine the prevalence of signs and symptoms of suspected dental, skeletal, and non-skeletal fluorosis, along with food habits, addictions, and use of fluoride containing toothpaste among participants taking water with fluoride concentration above the permissible limit, and to assess the changes in clinical manifestations of the above participants after they started consuming safe drinking water. MATERIALS AND METHODS: A longitudinal intervention study was conducted in three villages in Rampurhat Block I of Birbhum district of West Bengal to assess the occurrence of various dental, skeletal, and non-skeletal manifestations of fluorosis, along with food habits, addictions, and use of fluoride containing toothpaste among the study population and the impact of taking safe water from the supplied domestic and community filters on these clinical manifestations. The impact was studied by follow-up examination of the participants for 5 months to determine the changes in clinical manifestations of the above participants after they started consuming safe drinking water from supplied domestic filters and community filter with fluoride concentration below the permissible limit. The data obtained were compared with the collected data from the baseline survey. RESULTS: The prevalence of signs of dental, skeletal, and non-skeletal fluorosis was 66.7%, 4.8-23.8%, and 9.5-38.1%, respectively, among the study population. Withdrawal of source(s) identified for fluoride by providing domestic and community filters supplying safe water led to 9.6% decrease in manifestation of dental fluorosis, 2.4-14.3% decrease in various manifestations of skeletal fluorosis, and 7.1-21.5% decrease in various non-skeletal manifestations within 5 months. Following repeated motivation of participants during visit, there was also 9.7-38.1% decrease in the usage of fluoride containing toothpaste, and 9.8-45.3% and 7.3-11.9% decrease in the consumption of black lemon tea and tobacco, respectively, which are known sources of fluoride ingestion in our body and have an effect on the occurrence of various manifestations of fluorosis following drinking of safe water from domestic and community filters. CONCLUSION: Increased prevalence of dental, skeletal, and non-skeletal fluorosis was found among the study population. Withdrawal of source(s) identified for fluoride by supplying domestic and community filters, dietary restriction, and other nutritional interventions led to decrease in manifestation of the three types of fluorosis within 5 months.

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.

Critical appraisal of healthcare delivery services by multipurpose workers in rural West Bengal.

This cross-sectional study of 35 multipurpose workers (MPWs) of Goalpokhar--II (Chakulia) block selected by random sampling in the district of Uttar Dinajpur showed that 30 respondents were female mostly in the age group less than 30 years and rest were male in the age group of above 30 years. Majority of respondents (65.7%) were educated up to the level of higher secondary. On an average each MPW used to spend only 5.8 hours per week for home visit. During referral of the patients, the problems faced by the health workers were due to non-availability of vehicles (71.4%), difficulties in the means of communication ie, long distance, road problems, etc (85.7%), and lack of awareness about referral centre (2.8%). Only 5.5% of the MPWs stated absence of difficulty during referral to the higher facility. Regarding difficulties faced during transmission of health related information, 25.7% of MPWs were unaware of the location of the reporting centre; 17.4% of MPWs were unaware of authority to be informed and 14.3% of MPWs complained about social barrier and 22.8% experienced non-availability of manpower. However 42.9% of MPWs did not face any problem while transmitting health related events/information to the higher authority. Most of the respondents (23.5%) opined that their performance may be enhanced by increasing community awareness.

Community perception of Dengue in slum areas of metropolitan city of West Bengal.

Dengue is one of the major public health problems which can be controlled with active participation of the community. A cross sectional study was conducted in urban field practice area of Calcutta National Medical College to determine perception of general population on the disease Dengue. A total 161 individuals were interviewed regarding the different aspects of the Dengue fever. The result showed that out of total respondents, majority (68.9%) had knowledge that fever is the main symptom of the disease, though only 6.2% knew of retro-orbital pain as the pathognomic symptom of the disease. Out of total respondents 83.3% were unaware regarding modes of transmission of disease and the level of awareness is significantly higher among educated group (p < 0.05). 69.6% were unaware about the prevention of disease but there is no significant variation in relation to literacy status. Regarding awareness about vector control 60% of the respondents belonging to the lower socio economic class were unaware followed by 58.6% of the upper lower class. Only 39.1% had knowledge about breeding places of Aedes aegypti. The main source of information was found to be mass media (65%) and 7% of the respondents did not get any information about Dengue. Specific intervention measures such as Information Education Communication to be provided to the urban slum community for prevention and control of Dengue/Dengue haemorrhagic fever.