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Cadmium Background Levels in Groundwater in an Area Dominated by Agriculture
Author(s) -
Kubier Andreas,
Hamer Kay,
Pichler Thomas
Publication year - 2020
Publication title -
integrated environmental assessment and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 57
eISSN - 1551-3793
pISSN - 1551-3777
DOI - 10.1002/ieam.4198
Subject(s) - cadmium , groundwater , environmental science , agriculture , water resource management , environmental engineering , environmental chemistry , geography , engineering , chemistry , geotechnical engineering , organic chemistry , archaeology
Cadmium is a highly toxic trace metal, which can be of geogenic or anthropogenic origin, for example, minerals, phosphate fertilizers, and combustion emissions. Due to its low sorption affinity compared to other heavy metals, Cd is easily mobilized, potentially resulting in elevated Cd concentrations in groundwater. This study assessed background levels of Cd in groundwater related to hydrogeology and hydrogeochemical processes through evaluation of a large hydrogeochemical data set composed of groundwater analyses from 6300 wells in Northwestern Germany. Calculated Cd background levels in groundwater were between 0.01 µg/L in hydrogeological units with mainly reducing conditions and 0.98 µg/L in less reducing groundwater recharge areas. The results showed that groundwater Cd concentrations above 0.5 µg/L (the German threshold value) are not necessarily elevated but could be the regional or ambient background level, depending on the hydrogeological unit. What would be considered as ambient background levels, however, indicated the influence by continuous intensive land use as well as the local geology, which is dominated by glacial deposits. Cadmium concentrations in groundwater were mainly controlled by hydrogeochemical and hydrogeological parameters and not by the amount of anthropogenic Cd input, in particular through the use of phosphate fertilizers. Instead, analyses of the solid phase revealed that Cd release from the aquifer matrix due to changes in hydrogeochemical parameters was more likely. Aquifer sediments in Northwestern Germany can be enriched in Cd originating from multiple sources, which in turn can cause elevated Cd concentrations in groundwater. Integr Environ Assess Manag 2019;00:1–11. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)