Erkai He

Research interests

I obtained my bachelor degree in Environmental Science in 2009 from Nanjing Normal University and my master degree from Sun Yat-sen University in 2011. Research focused on using hyperaccumulator plants to remediate metal-contaminated soils. In September 2011, I joined the Animal Ecology Section as a PhD student. My main interests are metal ecotoxicity and soil remediation. In particular, to develop models that enable predicting the impacts of metals on soil animals. I am very interested in actively identifying and addressing such research issues in collaboration with other researchers; and in meaningfully influencing the direction of development of the immediate society

Selected Publications

Du, R.J., He, E.K., Tang, Y.T., Hu, P.J., Ying, R.R., Morel, J.L. and Qiu, R.L. (2011). How phytohormone IAA and chelator EDTA affect lead uptake by Zn/Cd hyperaccumulator Picris divaricata? International Journal of Phytoremediation 13:1024–1036.

Research project

Development of a terrestrial Biotic Ligand Model (t-BLM) to predict metal toxicity for soil organisms

The main objective of my PhD project is to develop the scientific basis for a consistent methodology for the environmental risk assessment of metals in soil. Starting point is the fact that metal bioavailability in soil is dependent on soil characteristics making that only a small fraction of the total metal content in soil is bioavailable. Studies with aquatic organisms have shown that the free metal ion is the most important form in which the metal is taken up; this is the basis of the so-called Free-Ion Activity Model (FIAM). Metal ion uptake by organisms may, however, also be affected by the competition of other cations, such as calcium, magnesium and H+ (pH). This notion has led to the development of Biotic Ligand Models (BLMs) that are used for risk assessment of a number of metals in surface water. For soil organisms, only few such BLMs are available, mainly for plants and earthworms, for a few metals only and not covering a wide range of soils and effects. Developing holistic terrestrial BLMs for predicting metal toxicity in soils with distinct properties therefore is the aim of this study. To explore the interaction of metals with cells on the so-called biotic ligand, uptake mechanisms have to be studies, and linked to the occurrence of toxic effects. With this a mechanistic frame work can be provided for developing t-BLMs. Such t-BLMs may also deal with the interaction of metals and predict mixture toxicity. My research will focus on studying dynamics of metal accumulation (toxicokinetics) and effects (toxicodynamics) in enchytraeids (Enchytraeus crypticus) as a basis for developing t-BLMs.

Participants:
Erkai He, Kees van Gestel, Rudo Verweij, Nico van Straalen