1. Prof. Dr. Bernd Nowack
Empa – Materials Science & Technology
Technology & Society Laboratory
Lerchenfeldstrasse 5
CH-9014 St. Gallen
Switzerland
Tel: +41 (0)58 765 76 92
nowack@empa.ch
http://www.empa.ch/nowack
April 25, 2016
Recommendation letter for Lei Deng
To whom it may concern
Lei Deng has worked at Empa, the Swiss Federal Laboratories for Materials Science and
Technology, as a master student from October 2015 to January 2016 in my group, the
Environmental Risk Assessment and Management group. I was the main supervisor of her
Master Thesis submitted to ETH Zürich. In her thesis Lei Deng had the task to perform an
environmental risk assessment for nano-iron oxides. My group has worked on assessing the
risks of nanomaterials for many years and the work of Lei Deng was to extend the approach
to a new nanomaterial that we haven’t covered so far. She had to very critically evaluate the
existing literature and to extract data from the studies that then could be used for the
evaluation. She had to learn and understand the requirements of our material flow model, the
model used for the evaluation of ecotoxicological data using species sensitivity distributions
and the risk assessment model. She collaborated with other members of my group in the
modeling phase to finally obtain the full environmental risk assessment of nano-iron oxides.
This new assessment constitutes a significant leap forward in assessing the environmental
risks of this nanomaterial. Lei Deng was very independent in her work but discussed the
work progress when needed and incorporated suggestions and new issues in the next work
steps.
The work involved heavily the evaluation of published data and Lei Deng managed this task
extremely well by systematically searching the relevant literature, critically evaluating the
quality of the papers and only using those that fulfilled our quality criteria. She even
suggested new approaches to obtain the desired information that we have now incorporated
into our toolbox. The work involved a lot of collaborations with other group members, a task
that Lei Deng managed extremely well with her very friendly personality and team-working
abilities. She never had any problems to integrate herself into the group and managed to fully
reach the goal we set at the beginning of her work. Lei Deng has shown an exceptional
productivity within the just four months of her stay.
The quality of the results she obtained in the just four months of her Master thesis is so good
that we are currently writing a scientific publication with the results that I expect to be
publishable in the best environmental science journals.
Overall I can only give the very best recommendations about Lei Deng. She has shown that
she can perfectly integrate into a team of researchers, perform her own work in constant
exchange and collaboration with others scientists, and deliver results perfectly on time and in
high quality. Lei Deng would be very well suited to continue her scientific career with a PhD

2. in environmental engineering. During her master thesis that just lasted for four months, she
has also shown that she can work well under the pressure of deadlines and to plan the work
so that the final goal can be reached. This would enable her to also look for positions in
smaller or larger companies, where she would be a perfect member of a project team,
working towards a common goal.
I wish Lei Deng all the best for her future career.
Sincerely
Bernd Nowack