From a new perspective, namely focusing on the interaction of selenium and mercury, this thesis provides new insights into traditional research on biogeochemical cycles of mercury in soil-plant interaction and associated human exposure and risks. The subject of this thesis is both valuable and timely, providing essential information not only on selenium-mercury interaction in the soil-plant system but also on how to assess the combined benefits and risk of co-exposure to mercury and selenium. This work also sheds light on future aspects regarding prevention, remediation and risk management for environmental mercury contamination. Presenting high-quality papers published in leading international SCI journals such as Environmental Health Perspectives and Environmental Science & Technology and having been recognized with the Special Award of Presidential Scholarship Award and Excellent Doctoral Dissertations Prize of the Chinese Academy of Sciences (CAS), this thesis offers a valuable resource for scientific communities, policy-makers and non-experts who are interested in this field.Dr. Hua Zhang works at the Norwegian Institute for Water Research (NIVA), Oslo, Norway.

Dr. Hua Zhang received his Ph.D degree in Environmental Geochemistry from University of Chinese Academy of Sciences (former Graduate University of Chinese Academy of Sciences) and worked as a Distinguished Consultant on environmental policy at the Foreign Cooperation Center, Ministry of Environmental Protection (FECO-MEP) in China. He is now a Research Scientist at Norwegian Institute for Water Research (NIVA). His broad research interest includes environmental policy, biogeochemistry of trace elements (mercury and selenium) and human health risk assessment. His recent interests also includes the links between contaminant cycling and topography, climate change, land types, etc., by using a wide range of methods from simulation models, monitoring and survey data analyses, field work and laboratory experiments.