| 1. |
- Bhowmick, Subhamoy, et al.
(author)
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Is Saliva a Potential Biomarker of Arsenic Exposure? : A Case-Control Study in West Bengal, India
- 2013
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 47:7, s. 3326-3332
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Journal article (peer-reviewed)abstract
- Saliva is a biological fluid that has not been used extensively as a biomonitoring tool in epidemiological studies. This study presents the arsenic (As) concentrations in saliva and urine samples collected from populations of West Bengal, India who had been previously exposed to high As levels in their drinking water. We found a significant (p < 0.05) association between the Log transformed Daily Ingestion of As (mu g day(-1)) and the As concentration in saliva (r = 0.68). Additionally, As concentration of saliva and urine also had a significant positive correlation (r = 0.60, p < 0.05). Male participants, smokers, and cases of skin lesion were independently and significantly associated with an increase in salivary As. Thus our findings show that saliva is a useful biomarker of As exposure in the study population. The study also advocates that measurement of the forms of As in saliva may additionally provide insight into the internal dose and any individual differences in susceptibility to As exposure.
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| 2. |
- Bhowmick, Subhamoy, et al.
(author)
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Speciation of Arsenic in Saliva Samples from a Population of West Bengal, India
- 2014
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:12, s. 6973-6980
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Journal article (peer-reviewed)abstract
- Saliva, an easily accessible biofluid, is validated as biomarker of arsenic (As) exposure in several villages of West Bengal, India. Pentavalent arsenic [As(V)] was found to be the predominant species in saliva, with the amount of inorganic As [As(V) and trivalent form, As(III)] being more than half of the total As in the samples. Significant association was found between total daily ingestion of As and As(V) (r = 0.59; p = 0.000), As(III) (r = 0.60; p = 0.000), dimethylarsinous acid (DMA(V)) (r = 0.40; p = 0.000), and monomethylarsonous acid (MMA(V)) (r = 0.44; p = 0.000), implying that these species have mainly been derived from the methylation of the inorganic As in the water that study participants drank and the food they ate. Analysis of confounding effects of age, sex, smoking, body mass index and the prevalence of skin lesion suggests that women and controls with no skin lesion had a higher capacity to methylate the ingested As compared to the rest of the population. Thus, our study demonstrates that As species in saliva can be an useful tool to predict the individual susceptibility where higher As exposure and a lower methylation capacity are implicated in the development of As-induced health effects.
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| 3. |
- Halder, Dipti, et al.
(author)
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Arsenic species in raw and cooked rice : Implications for human health in rural Bengal
- 2014
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In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 497, s. 200-208
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Journal article (peer-reviewed)abstract
- This study compares the concentrations of total and different species of arsenic (As) in 29 pairs of raw and cooked rice samples collected from households in an area of West Bengal affected by endemic arsenicism. The aim is to investigate the effects of indigenous cooking practice of the rural villagers on As accumulation and speciation in cooked rice. It is found that inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). Cooking of rice with water low in As (<10 mu g L-1) significantly decreases the total and inorganic As content in cooked rice compared to raw rice. Arsenic concentration is mainly decreased during boiling of rice grains with excess water. Washing of rice grains with low As water has negligible effect on grain As concentration. The study suggests that rice cooking with low As water by the villagers is a beneficial risk reduction strategy. Despite reductions in As content in cooked rice because of cooking with low As water, the consumption of cooked rice represents a significant health threat (in terms of chronic As toxicity) to the study population.
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| 4. |
- Halder, Dipti, et al.
(author)
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Assessment of arsenic exposure risk from drinking water and dietary component in West Bengal, India
- 2013
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Conference paper (peer-reviewed)abstract
- The current status of arsenic (As) exposure risk from drinking water and different dietary components in rural Bengal has been compared in the present study. This study shows that the consumption of rice is the major source of dietary intake of inorganic As among the population when they are drinking As safe water. Consumption of vegetables does not pose a significant health threat to the population independently; it nevertheless can increase the total daily intake of inorganic As (TDI-iAs). The results indicate that when people are drinking water with As concentration <10 μg L-1, in 35% of the cases the total daily intake of inorganic As (TDI-iAs) exceeds the previous provisional tolerable daily intake (PTDI) value of 2.1 μg day-1 kg-1 BW, recommended by World Health Organization (WHO). It should be mention here that the joint FAO/WHO expert committee on food additives (JECFA) has withdrawn the previous PTDI value in their 72nd meeting because PTDI value was in the lower range of bench mark dose level for 0.5% increased of lung cancer. However, Codex Committee on Contaminants in Foods (CCCF) has argued that TDI-iAs below BMDL0.5 does not indicates that there is no risk and this motivated us to compare TDI-iAs of the participants with the previous PTDI value of 2.1 μg day-1 kg-1 bw. At the As concentration level <10 μg L-1in drinking water, the consumption of rice is the major source of daily intake of inorganic As. When As concentration in drinking water exceeds 10 μg L-1, drinking water and rice consumption contributes almost equally (~40% from rice, ~50% from drinking water, and 10% from vegetables according to median DI-iAs) and TDI-iAs exceeds previous PTDI for all the participants. The relative contribution of daily intake of iAs from drinking water (DI-iAs-DW) largely predominates over daily intake of iAs from rice (DI-iAs-R) when As concentration in drinking water exceeds 50 μg L-1. This study implies that when consumption of rice contributes significantly to the TDI-iAs, supply of drinking water to the population considering national drinking water standard of India and Bangladesh as a safety measure for As might compound the As exposure largely by increasing TDI-iAs. Thus it can be concluded that any effort to mitigate the As poisoning of rural villagers in Bengal must look beyond the drinking water and consider all the routes of exposure.
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| 5. |
- Halder, Dipti, et al.
(author)
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Consumption of Brown Rice : A Potential Pathway for Arsenic Exposure in Rural Bengal
- 2012
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 46:7, s. 4142-4148
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Journal article (peer-reviewed)abstract
- This study assesses the arsenic (As) accumulation in different varieties of rice grain, that people in rural Bengal mostly prefer for daily consumption, to estimate the potential risk of dietary As exposure through rice intake. The rice samples have been classified according to their average length (L) and L to breadth (B) ratio into four categories, such as short-bold (SB), medium-slender (MS), long-slender (LS), and extra-long slender (ELS). The brown colored rice samples fall into the SB, MS, or LS categories; while all Indian Basmati (white colored) are classified as ELS. The study indicates that the average accumulation of As in rice grain increases with a decrease of grain size (ELS: 0.04; LS: 0.10; MS: 0.16; and SB: 0.33 mg kg(-1)), however people living in the rural villages mostly prefer brown colored SB type of rice because of its lower cost. For the participants consuming SB type of brown rice, the total daily intake of inorganic As (TDI-iAs) in 29% of the cases exceeds the previous WHO recommended provisional tolerable daily intake value (2.1 mu g day(-1) kg(-1) BW), and in more than 90% of cases, the As content in the drinking water equivalent to the inorganic As intake from rice consumption (C-W,C-eqv) exceeds the WHO drinking water guideline of 10 mu g L-1. This study further demonstrates that participants in age groups 18-30 and 51-65 yrs are the most vulnerable to the potential health threat of dietary As exposure compared to participants of age group 31-50 yrs, because of higher amounts of brown rice consumption patterns and lower BMI.
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