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The Shiels Laboratory


Food chain transfer and toxicity of metallic nanoparticles in freshwater

Funding: Project available for individuals with self arranged funding.


Engineered metallic nanoparticles (NPs) are used widely in many industries and exposure to the consumer and to the environment is increasing, yet impacts are still unclear. Much research has focussed on exposure of individual organisms to single NPs and there has been no in depth examination of movement, behaviour and toxicity of NPs through the food chain, including transfer from algae to fish. Predicted exposure of humans is highest for silver (Ag)-NPs which are widely used due to their anti-bacterial properties. The overall aim of this studentship is to examine metallic NP accumulation and toxicity on three model species that form a freshwater food chain, and identify ecotoxicological effects of environmentally relevant concentrations of Ag-NP in comparison to the biologically inert titanium NP.

Algae form the basis of most aquatic food chains and are an entry point for NPs that may then transfer up the food chain via herbivorous crustacean and grazing fish. We have shown that Ag-NPs accumulate in the microalga Chlamydomonas and transfer into the zooplanktonic crustacean Daphnia through feeding on the algae. This studentship will perform an in depth analysis of NP accumulation, transfer and toxicity Chlamydomonas, Daphnia, and brown trout (Salmo trutta)

The specific aims of the project are:

  • To characterise the mechanisms for Ag-NP accumulation into microalgae
  • In comparison with Ti-NPs, quantify potential and characteristics for water-borne and diet-borne NPs to transfer into Daphnia, and brown trout
  • To examine physiological indicators of NP toxicity in each model organism

The knowledge acquired from this study will provide an assessment of the risk of NP toxicity to the freshwater food chain and assist in the formulation of standards and guidelines relating to NP toxicity.

The student will receive training in algal culture, animal husbandry, trace metal analysis and behavioural measures of toxicity.

Related Publications

  • McTeer, J, Dean, A P, White, K N & Pittman J K (submitted). Bioaccumulation of silver nanoparticles into Dapnia magna from a freshwater algal diet and the impact of phosphate concentration. Nanotechnology.
  • Quiroz-Vazquez, P, Sigee, D C & White, K N (2010) Bioavailability and toxicity of aluminium in a model planktonic food-chain (Chlamydomonas-Daphnia) at neutral pH. Limnologica, 40, 269–277.