Results for “"A. Horneman"”

Alexander van Geen, Yan Zheng, Roelof Versteeg, M. Stute et al.

Arsenic concentrations measured by graphite furnace atomic absorption range from < 5 to 900 μg/L in groundwater pumped from 6000 wells within a 25 km 2 area of Bangladesh. The proportion of wells that exceed the Bangladesh standard for drinking water of 50 μg/L arsenic increases with depth from 2...

Alexander van Geen, Habibul Ahsan, A. Horneman, Ratan Dhar et al.

OBJECTIVE: To survey tube wells and households in Araihazar upazila, Bangladesh, to set the stage for a long-term epidemiological study of the consequences of chronic arsenic exposure. METHODS: Water samples and household data were collected over a period of 4 months in 2000 from 4997 contiguous tub...

Yan Zheng, Alexander van Geen, M. Stute, Ratan Dhar et al.

M. Stute, Yan Zheng, Peter Schlösser, A. Horneman et al.

The elevated arsenic (As) content of groundwater from wells across Bangladesh and several other South Asian countries is estimated to slowly poison at least 100 million people. The heterogeneous distribution of dissolved arsenic in the subsurface complicates understanding of its release from the sed...

Alexander van Geen, Yan Zheng, S. L. Goodbred, A. Horneman et al.

Whereas serious health consequences of widespread consumption of groundwater elevated in As have been documented in several South Asian countries, the mechanisms responsible for As mobilization in reducing aquifers remain poorly understood. We document here a previously unrecognized and consistent r...

Alexander van Geen, Yan Zheng, Zhongqi Cheng, Z. Aziz et al.

Z. Aziz, Alexander van Geen, M. Stute, Roelof Versteeg et al.

The high‐degree of spatial variability of dissolved As levels in shallow aquifers of the Bengal Basin has been well documented but the underlying mechanisms remain poorly understood. We compare here As concentrations measured in groundwater pumped from 4700 wells <22 m (75 ft) deep across a 25 km...

Alexander van Geen, T. Protus, Zhongqi Cheng, A. Horneman et al.

Profiles of groundwater and sediment properties were collected at three sites in Bangladesh with an inexpensive sampling device that is deployed by modifying the local manual drilling method. Dissolved As concentrations in the groundwater samples ranging from 5 to 600 microg/L between 5 and 50 m dep...

A. Horneman, M. Stute, Peter Schlösser, William M. Smethie et al.

Chlorofluorocarbons CFC-11 (CCl(3)F), CFC-12 (CCl(2)F(2)), and CFC-113 (CCl(2)F-CClF(2)) are used in hydrology as transient tracers under the assumption of conservative behavior in the unsaturated and saturated soil zones. However, laboratory and field studies have shown that these compounds are not...

Alexander van Geen, Z. Aziz, A. Horneman, Beth Weinman et al.

Dao Viet Nga, Pham Thi Kim Trang, Vu Thi Duyen, Tran Thi et al.

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 Hano...

Kazi Matin Ahmed, A. van Green, Yan Zheng, M. Stute et al.

Yan Zheng, Beth Weinman, S. L. Goodbred, Alexander van Geen et al.

Yan Zheng, Alexander van Geen, M. Stute, Ratan Dhar et al.