ARSENIC POISONING AT TUBE WELL IN RED RIVER DELTA CASE STUDY AT SON DONG VILLAGE

Joint Research on Environmental Science and Technology for the Eart

ARSENIC POLLUTION IN TUBE WELL WATER AT HANOI SUBURB VILLAGES

Joint Research on Environmental Science and Technology for the Eart

Spatial variations of arsenic in groundwater from a transect in the Northwestern Hanoi

Arsenic contamination of groundwater is a major health problem and has been a growing concern in the last decade in several regions of the world, especially in South and Southeast Asia, including the Red River delta, Vietnam. Regional groundwater studies have been carried out in the vicinity of Hanoi, on the banks of the Red River and its adjacent floodplains. In this study, the groundwater from a transect in the Northwestern area of Hanoi was examined. The results showed that 28.8% the wells of the B-B’ transect exceed the WHO guideline value for arsenic concentration in drinking water. The arsenic concentrations varied in a wide range from point to point, with the highest concentration found at Van Phuc and the lowest one found at Cam Yen. They also varied accordingly to the depth.References Anawar H.M., Akai J., Sakugawa H., Sakugawa H., 2004. Mobilization of arsenic from subsurface sediments by effect of bicarbonate ions in groundwater. Chemosphere, 54, 753-762. Appelo C.A.J., Postma D., 2004. Geochemistry, Groundwater and Pollution, second edition. Berg M., Tran H.C., Nguyen T.C., Pham H.V., Schertenleib R., Giger W., 2001. Arsenic contamination of groundwater and drinking water in Vietnam: A human health threat. Environmental Science Technology, 35(13), 2621-2626. Berg M., Stengel C., Pham T.K.T., Pham H.V., Sampson M.L., Leng M., Samreth S., Fredericks D., 2007. Magnitude of arsenic pollution in the Mekong and Red River Delta - Cambodia and Vietnam. Science of the Total Environment, 372, 413-425. Chowdhury U.K., Biswas B.K., Chowdhury T.R., Samanta G., Mandal B.K., Basu G.C., Chanda C.R., Lodh D., Saha K.C., Mukherjee S.K., Roy S., Kabir S., Quamruzzaman Q., Chakraborti D., 2000. Groundwater Arsenic Contamination in Bangladesh and West Bengal, India. Environmental Health Perpectives, 108(5), 393-397. Eiche E., Neumann T., Berg M., Weinman B., Van Geen A., Norra S., Berner Z., Pham T.K.T., Pham H.V., Stuben D., 2008. Geochemical processes underlying a sharp contrast in groundwater arsenic concentrations in a village on the Red River delta, Vietnam. Applied Geochemistry, 23, 3143-3154. Fendorf S., Michael H.A., Van Geen A., 2010. Spatial and temporal variations of groundwater arsenic in South and Southeast Asia. Science, 328, 1123. Doi: 10.1126/Science.1172974. General Statics Office of Vietnam, 2015. Regional statistics of Area, Population and Population density. McArthur J.M., Ravenscroft P., Safuilla S., Thirlwall M.F., 2001. Arsenic in groundwater: Testing pollution mechanisms for sedimentary aquifers in Bangladesh. Water Resources Research, 31(1), 109-117. Postma D., Larsen F., Nguyen T.M.H., Mai T.D., Pham H.V., Pham Q.N., Jessen S., 2007. Arsenic in groundwater of the Red River floodplain, Vietnam: Controlling geochemical processes and reactive transport modeling. Geochimica et Cosmochimica Acta, 71, 5054-5071. Postma D., Larsen F., Nguyen T.T., Pham T.K.T., Jakobsen R., Pham Q.N., Tran V.L., Pham H.V., Murray A.S., 2012. Groundwater arsenic concentrations in Vietnam controlled by sediment age. Nature GeoScience. Doi: 10.1038/NGEO1540. Smedley P.L., Kinniburgh D.G., 2002. A review of the source, behavior and distribution of arsenic in natural waters. Applied Geochemistry, 17, 517-568. Smedley P.L., 2006. Sources and distribution of arsenic in groundwater and aquifers. In T. Appelo (Ed.), Arsenic in Groundwater - A World Problem, 4-33. Van Geen A., Bostick B.C., Pham T.K.T., Vi M.L., Nguyen N.M., Dao M.P., Pham H.V., Radloff K., Aziz A., Mey J.L., Stahl M.O., Harvey C.H., Oates P., Weinman B., Stengel C., Frei F., Kipfer R., Berg M., 2013. Retardation of arsenic transport through a Pleistocene aquifer. Nature, 501, 204-208. Van Geen, A., Zheng Y., Versteeg R., Stute M., Horneman A., Dhar R., Steckler M., Gelman A., Small C., Ahsan H., Graziano J.H., Hussain I., Ahmed K.M., 2003. Spatial variability of arsenic in 6000 tube wells in a 25 km2 area of Bangladesh. Water Resources Research, 39(5), 1140. Doi:10.1029/2002WR001617. World Health Organization, 2011. Guidelines for drinking-water quality, fourth edition. Winkel L.H.E., Pham T.K.T., Vi M.L., Stengel C., Amini M., Nguyen T.H., Pham H.V., Berg M., 2011. Arsenic pollution of groundwater in Vietnam exacerbated by deep aquifer exploitation for more than a century. PNAS, 108(4), 1246-1251

ARSENIC POLLUTION IN GROUNDWATER IN RED RIVER DELTA, VIETNAM : SITUATION AND HUMAN EXPOSURE

Joint Research on Environmental Science and Technology for the Eart

Retardation of arsenic transport through a Pleistocene aquifer

Groundwater drawn daily from shallow alluvial sands by millions of wells over large areas of south and southeast Asia exposes an estimated population of over a hundred million people to toxic levels of arsenic. Holocene aquifers are the source of widespread arsenic poisoning across the region. In contrast, Pleistocene sands deposited in this region more than 12,000 years ago mostly do not host groundwater with high levels of arsenic. Pleistocene aquifers are increasingly used as a safe source of drinking water and it is therefore important to understand under what conditions low levels of arsenic can be maintained. Here we reconstruct the initial phase of contamination of a Pleistocene aquifer near Hanoi, Vietnam. We demonstrate that changes in groundwater flow conditions and the redox state of the aquifer sands induced by groundwater pumping caused the lateral intrusion of arsenic contamination more than 120 metres from a Holocene aquifer into a previously uncontaminated Pleistocene aquifer. We also find that arsenic adsorbs onto the aquifer sands and that there is a 16–20-fold retardation in the extent of the contamination relative to the reconstructed lateral movement of groundwater over the same period. Our findings suggest that arsenic contamination of Pleistocene aquifers in south and southeast Asia as a consequence of increasing levels of groundwater pumping may have been delayed by the retardation of arsenic transport

Retardation of arsenic transport through a Pleistocene aquifer

Groundwater drawn daily from shallow alluvial sands by millions of wells over large areas of south and southeast Asia exposes an estimated population of over a hundred million people to toxic levels of arsenic1. Holocene aquifers are the source of widespread arsenic poisoning across the region2, 3. In contrast, Pleistocene sands deposited in this region more than 12,000 years ago mostly do not host groundwater with high levels of arsenic. Pleistocene aquifers are increasingly used as a safe source of drinking water4 and it is therefore important to understand under what conditions low levels of arsenic can be maintained. Here we reconstruct the initial phase of contamination of a Pleistocene aquifer near Hanoi, Vietnam. We demonstrate that changes in groundwater flow conditions and the redox state of the aquifer sands induced by groundwater pumping caused the lateral intrusion of arsenic contamination more than 120 metres from a Holocene aquifer into a previously uncontaminated Pleistocene aquifer. We also find that arsenic adsorbs onto the aquifer sands and that there is a 16–20-fold retardation in the extent of the contamination relative to the reconstructed lateral movement of groundwater over the same period. Our findings suggest that arsenic contamination of Pleistocene aquifers in south and southeast Asia as a consequence of increasing levels of groundwater pumping may have been delayed by the retardation of arsenic transport.National Science Foundation (U.S.) (NSF grant EAR09-11557)Swiss Agency for Development and Cooperation (Grant NAFOSTED 105-09-59-09 to CETASD, the Centre for Environmental Technology and Sustainable Development (Vietnam))National Institute of Environmental Health Sciences (NIEHS grant P42 ES010349)National Institute of Environmental Health Sciences (NIEHS grant P42 ES016454

An open label randomized controlled trial of tamoxifen combined with amphotericin B and fluconazole for cryptococcal meningitis

Background: Cryptococcal meningitis has high mortality. Flucytosine is a key treatment but is expensive and rarely available. The anti-cancer agent tamoxifen has synergistic anti-cryptococcal activity with amphotericin in vitro. It is off-patent, cheap, and widely available. We performed a trial to determine its therapeutic potential. Methods:Open label randomized controlled trial. Participants received standard care - amphotericin combined with fluconazole for the first two weeks - or standard care plus tamoxifen 300mg/day. The primary end point was Early Fungicidal Activity (EFA) - the rate of yeast clearance from cerebrospinal fluid (CSF). Trial registration https://clinicaltrials.gov/ct2/show/NCT03112031 . Results: 50 patients were enrolled, (median age 34 years, 35 male). Tamoxifen had no effect on EFA (- 0.48log10 colony-forming units/mL/CSF control arm versus -0.49 tamoxifen arm, difference - 0.005log10CFU/ml/day, 95%CI: -0.16, 0.15, P=0.95). Tamoxifen caused QTc prolongation. Conclusion: High dose tamoxifen does not increase the clearance rate of Cryptococcus from CSF. Novel, affordable therapies are needed. Funding:The trial was funded through the Wellcome Trust Asia Programme Vietnam Core Grant 106680 and a Wellcome Trust Intermediate Fellowship to JND grant number WT097147MA

Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications

This work was supported by a restricted research grant of Bayer AG