Research Scientist, Head Environmental Inorganic Geochemistry
Molecular to global scale biogeochemical processes that control the mobility and cycling of health-impacting trace elements in the environment.
The effects of environmental stresses, such as human activities and climate change on trace element cycles.
Predictions of trace element distributions based on biogeochemical and climate data.
The global cycle of selenium
Selenium is a trace element that is of fundamental importance to human health. However, it is also an element with a small range between dietary deficiency and toxic dosages. This narrow range combined with the higly uneven geographical variation in environmental selenium concentrations has resulted in significant health problems. To prevent future health hazards it is essential to get a better understanding of the processes that control the global distribution of selenium. To advance this understanding we are investigating globally important sources, pathways and sinks of selenium in the environment.
Arsenic contamination of groundwaters in Southeast Asia
Contamination of groundwater with the naturally occuring trace element arsenic is a major health problem, especially in South and Southeast Asia. Arsenic is enriched in the groundwater via process that involve microbial and chemical reductive dissolution of arsenic-bearing minerals in aquifer sediments. To efficiently respond to the arsenic crisis, it is of crucial importance to recognise areas that are at high risk of groundwater arsenic contamination. To facilitate this process we have developed large-scale prediction maps that indicate areas that are at risk of arsenic groundwater contamination. Further studies aimed at elucidating processes of As mobilization are planned.
- L.H.E. Winkel, C.A. Johnson, M. Lenz, T. Grundl, O.X. Leupin, M. Amini, L. Charlet (2012) Environmental selenium research: from microscopic processes to global understanding (Feature). Environmental Science and Technology 46, 571-579.
- L.H.E. Winkel, C. Stengel, M. Amini, M. Berg, Pham Thi Kim Trang, Vi Mai Lan, Pham Hung Viet, Nguyen Thi Ha, Nguyen Van Dan (2011) Arsenic pollution of groundwater in Vietnam exacerbated by deep aquifer exploitation for more than a century. PNAS 108, 1246-1251.
- L. Winkel, J. Feldmann and A.A. Meharg (2010) Quantitative and qualitative trapping of volatile methylated selenium species entrained through nitric acid. Environmental Science and Technology 44, 382-387.
- L. Winkel, M. Berg, M. Amini, S.J. Hug and C.A. Johnson (2008) Predicting groundwater arsenic contamination in Southeast Asia from surface parameters. Nature Geoscience 1, 536-542.
- M. Amini, K.C. Abbaspour, M. Berg, L. Winkel, S.J. Hug, E. Hoehn, H. Yang, A.C. Johnson (2008) Statistical Modeling of Global Geogenic Arsenic Contamination in Groundwater. Environmental Science and Technology 42, 3669-3675.