Time filter

Source Type

von Bromssen M.,KTH Royal Institute of Technology | von Bromssen M.,Ramboll | Markussen L.,Ramboll | Bhattacharya P.,KTH Royal Institute of Technology | And 9 more authors.
Journal of Hydrology | Year: 2014

Exploitation of groundwater from shallow, high prolific Holocene sedimentary aquifers has been a main element for achieving safe drinking water and food security in Bangladesh. However, the presence of elevated levels of geogenic arsenic (As) in these aquifers has undermined this success. Except for targeting safe aquifers through installations of tubewells to greater depth, no mitigation option has been successfully implemented on a larger scale. The objective of this study has been to characterise the hydrostratigraphy, groundwater flow patterns, the hydraulic properties to assess the vulnerability of low-arsenic aquifers at Matlab, in south-eastern Bangladesh, one of the worst arsenic-affected areas of the country. Groundwater modelling, conventional pumping test using multilevel piezometers, hydraulic head monitoring in piezometer nests, 14C dating of groundwater and assessment of groundwater abstraction were used. A model comprising of three aquifers covering the top 250m of the model domain showed the best fit for the calibration evaluation criteria. Irrigation wells in the Matlab area are mostly installed in clusters and account for most of the groundwater abstraction. Even though the hydraulic heads are affected locally by seasonal pumping, the aquifer system is fully recharged from the monsoonal replenishment. Groundwater simulations demonstrated the presence of deep regional flow systems with recharge areas in the eastern, hilly part of Bangladesh and shallow small local flow systems driven by local topography. Based on modelling results and 14C groundwater data, it can be concluded that the natural local flow systems reach a depth of 30m b.g.l. in the study area. A downward vertical gradient of roughly 0.01 down to 200m b.g.l. was observed and reproduced by calibrated models. The vertical gradient is mainly the result of the aquifer system and properties rather than abstraction rate, which is too limited at depth to make an imprint. Although irrigation wells substantially change local flow pattern, targeting low-As aquifers seems to be a suitable mitigation option for providing people with safe drinking water. However, installing additional irrigation- or high capacity production wells at the same depth is strongly discouraged as these could substantially change the groundwater flow pattern. The results from the present study and other similar studies can further contribute to develop a rational management and mitigation policy for the future use of the groundwater resources for drinking water supplies. © 2014 Elsevier B.V. Source

Robinson C.,University of Western Ontario | Bromssen M.V.,KTH Royal Institute of Technology | Bromssen M.V.,Ramboll | Bhattacharya P.,KTH Royal Institute of Technology | And 8 more authors.
Applied Geochemistry | Year: 2011

Targeting shallow low-As aquifers based on sediment colour may be a viable solution for supplying As-safe drinking water to rural communities in some regions of Bangladesh and West Bengal in India. The sustainability of this solution with regard to the long-term risk of As-safe oxidized aquifers becoming enriched with As needs to be assessed. This study focuses on the adsorption behaviour of shallow oxidized sediments from Matlab Region, Bangladesh, and their capacity to attenuate As if cross-contamination of the oxidized aquifers occurs. Water quality analyses of samples collected from 20 tube-wells in the region indicate that while there may be some seasonal variability, the groundwater chemistry in the reduced and oxidized aquifers was relatively stable from 2004 to 2009. Although sediment extractions indicate a relatively low amount of As in the oxidized sediments, below 2.5mgkg-1, batch isotherm experiments show that the sediments have a high capacity to adsorb As. Simulations using a surface complexation model that considers adsorption to amorphous Fe(III) oxide minerals only, under-predict the experimental isotherms. This suggests that a large proportion of the adsorption sites in the oxidized sediments may be associated with crystalline Fe(III) oxides, Mn(IV) and Al(III) oxides, and clay minerals. Replicate breakthrough column experiments conducted with lactose added to the influent solution demonstrate that the high adsorption capacity of the oxidized sediments may be reduced if water drawn down into the oxidized aquifers contains high levels of electron donors such as reactive dissolved organic C. © 2011 Elsevier Ltd. Source

Bhattacharya P.,KTH Royal Institute of Technology | Hossain M.,KTH Royal Institute of Technology | Rahman S.N.,KTH Royal Institute of Technology | Robinson C.,NGO Forum for Drinking Water Supply and Sanitation | And 13 more authors.
Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering | Year: 2011

Temporal and seasonal variability of As concentrations in groundwater were evaluated in As-affected areas of Matlab, southeastern Bangladesh. Groundwater samples from 61 randomly selected tubewells were analyzed for As concentrations over a period of three years and four months (from July 2002 to November 2005) and monitored seasonally (three times a year). The mean As concentrations in the sampled tubewells decreased from 153 to 123 μg/L during July 2002 to November 2005. Such changes were pronounced in tubewells with As concentration >50 μg/L than those with As concentrations <50 μg/L. Similarly, individual wells revealed temporal variability, for example some wells indicated a decreasing trend, while some other wells indicated stable As concentration during the monitoring period. The mean As concentrations were significantly higher in Matlab North compared with Matlab South. The spatial variations in the mean As concentrations may be due to the differences in local geological conditions and groundwater flow patterns. The variations in mean As concentrations were also observed in shallow (<40 m) and deep (>40 m) wells. However, to adequately evaluate temporal and seasonal variability of As concentration, it is imperative to monitor As concentrations in tubewells over a longer period of time. Such long-term monitoring will provide important information for the assessment of human health risk and the sustainability of safe drinking water supplies. Copyright © Taylor &Francis Group, LLC. Source

Milton A.H.,University of Newcastle | Smith W.,University of Newcastle | Rahman B.,University of Sydney | Ahmed B.,Khulna University | And 4 more authors.
Asia-Pacific Journal of Public Health | Year: 2010

Malnutrition among the rural Bangladeshi women of reproductive age is still very high. This high prevalence attributes to a range of adverse health consequences on the women and their offspring. A total of 2341 women aged between 20 and 45 years residing in the study area were interviewed in this cross-sectional study. Information on socioeconomic variables, nutritional status, and pregnancy-related history was obtained using interviewer administered questionnaire. A total of 34% of the reproductive aged rural women suffer from malnutrition. A multivariate analysis shows association between malnutrition and monthly household income, history of taking oral contraceptive, current pregnancy status, and history of breastfeeding. The final regression model shows a statistically significant decreasing trend in malnutrition status with increasing income (P for trend <.001). The economic and health consequences of malnutrition in this group of women are enormous. National nutritional program should target this women group for any intervention with a special priority. © 2010 APJPH. Source

Milton A.H.,University of Newcastle | Shahidullah S.M.,NGO Forum for Drinking Water Supply and Sanitation | Smith W.,University of Newcastle | Hossain K.S.,Center for Health and Development | And 2 more authors.
International Journal of Environmental Research and Public Health | Year: 2010

The role of nutritional factors in arsenic metabolism and toxicity is yet to be fully elucidated. A low protein diet results in decreased excretion of DMA and increased tissue retention of arsenic in experimental studies. Malnourished women carry a higher risk of adverse pregnancy outcomes. Chronic exposure to high arsenic (>50 μg/L) through drinking water also increases the risk of adverse pregnancy outcomes. The synergistic effects (if any) of malnutrition and chronic arsenic exposure may worsen the adverse pregnancy outcomes. This population based case control study reports the association between chronic arsenic exposure and nutritional status among the rural women in Bangladesh. 348 cases (BMI < 18.5) and 360 controls (BMI 18.5-24.99) were recruited from a baseline survey conducted among 2,341 women. An excess risk for malnutrition was observed among the participants chronically exposed to higher concentrations of arsenic in drinking water after adjusting for potential confounders such as participant's age, religion, education, monthly household income and history of oral contraceptive pills.Women exposed to arsenic >50 μg/L were at 1.9 times (Odds Ratio = 1.9, 95% CI = 1.1-3.6) increased risk of malnutrition compared to unexposed. The findings of this study suggest that chronic arsenic exposure is likely to contribute to poor nutritional status among women of 20-45 years. © 2010 by the authors. Source

Discover hidden collaborations