Wednesday, 28 January 2015 16:04

Working Group – a Portrait: Chair for Sustainable Chemistry and Material Resources at Leuphana University Lüneburg Featured

InVitroJobs presents scientists and their innovative research in a regular feature called “Working Group – a Portrait”. We focus on newly developed methods, their evaluation and their potential for reducing and where possible replacing animal experimentation according to the 3R principles of Russel & Burch (reduce, refine, replace).

In this article we present an institute that researches the retention of organic substances in the environment and their evaluation. Head of the institute is the chemist Prof. Dr. Klaus Kümmerer. His research foci are sustainable chemistry, material resources and trace elements in the aquatic environment. Prof. Kümmerer looks for new properties for pharmaceuticals, with the goal of making them degradable in rivers and lakes. To this end the institute employs computer-based methods. A staff member also has the task of modelling and evaluating the global dispersion of harmful substances.


Working Group – a Portrait:
Chair for Sustainable Chemistry and Material Resources
at Leuphana University Lüneburg

In this article we present an institute that researches the retention of organic substances in the environment and their evaluation. Head of the institute is the chemist Prof. Dr. Klaus Kümmerer. His research foci are sustainable chemistry, material resources and trace elements in the aquatic environment. Prof. Kümmerer looks for new properties for pharmaceuticals, with the goal of making them degradable in rivers and lakes. To this end the institute employs computer-based methods. A staff member also has the task of modelling and evaluating the global dispersion of harmful substances.

New molecules for proven pharmaceuticals and chemicals with the same efficacy but better environmental compatibility are designed on the computer and their properties are calculated. Once a new substance has been synthesised, in vitro tests for their environmental compatibility are conducted using bacteria to test the substance’s biodegradability.

Work at the Institute for Sustainable and Environmental requires openness to unconventional ideas and interdisciplinary work. Research is conducted in an interdisciplinary and transdisciplinary setting in the Faculty of Sustainability – with national and international partnerships.

Photo: Copyright M. Busch/Leuphana University Lüneburg

The photolytic degradation is tested with UV light. The substance is then tested for specific undesired effects, e.g. mutagenicitya and genotoxicityb.

The research pertains to an important aspect of so-called “Sustainable Chemistry”: Scientists intend to reduce potential hazards of chemicals, including human and veterinary drugs, by means of improved molecule and process design, thus preventing environmental pollution from the start. This also benefits the animals used in ecotoxicity tests.

Green Chemistry

In 1998, the American chemists Paul Anastas und John C. Warner published the 12 Principles of Green Chemistry1,2. One of these 12 principles is hazard reduction by developing synthetic methods to minimise toxicity involved in the production of chemicals. A further important goal is to design molecules that are completely degradable.

Pharmaceuticals and other traces can be found in rivers and lakes, but also in individual cases in tap water

Small molecules are to be found in practically all bodies of water. Often only a small proportion can be filtered by sewerage treatment. Often they come from households and enter the water system via the toilets. Rivers and lakes contain pharmaceutical residues, even if in low concentrations. To date, scientists have proven the presence of some 150 pharmaceutical drugs in surface waters, sediments, ground water and soil3. Especially painkillers, antibiotics and psychotropic drugs pollute our environment. In Germany alone, 344,880 kg of the painkiller ibuprofen were consumed in 20074. And the households need not even dispose of expired medication via the toilet; it is sufficient that the daily excretions enter the sewerage and from there reach the surface water. According to a study5, only ten per cent of all surface water is classified as “very clean”. However, it is not only the surface water in which one can find pharmaceutical residues, but also in the soil, the ground water and in some cases even tap water. The residues of veterinary drugs enter the soil via liquid manure3. They demonstrably harm the environment, as they persist there for a long time.

Excretion products enter sewerage systems on a daily basis, carrying pharmaceutical residues that cannot be filtered out by treatment plants.
Photos, from left to right: saksrifotolia,; Dieter Schütz,

Ecotoxicologists warned years ago about harmful effects, e.g. feminisation of fishes and reduced fertility in organisms. The long-term influence of so-called endocrine disruptors – and residues from contraceptive pills or hormone substitution therapies are just that – has been discussed as possible causes for human diseases for some time. In 2013 the World Health Organization (WHO) demanded new studies into the mechanisms of endocrine disruptors6. In Germany, for instance, the foundation Deutsche Bundesstiftung Umwelt (BDU) has called for “sustainable pharmacy” projects that address the degradability of pharmaceutical active agents. The following address provides a summary with videos pertinent to the set of issues: To take the psychotropic drug oxazepam as an example, scientists recently discovered that it can prolong the life expectancy of perch. The concluded that within certain bounds the substance could influence the structure of the fish population, and demanded that ecotoxicological tests be extended to include therapeutic effects of substances on the population species7.


Sustainability means reconciling the needs of today’s population with the development options of future generations8. The current level of consumption should allow provide future generations the same possibilities for development, i.e. economic activity should not be at the cost of future generations9.

Sustainable chemistry in particular means using and converting material resources without causing harm to future generations, but also includes social and economic questions with regard to chemical products.


Photo: R_K_B_by_Denise,

An environmental risk assessment must be conducted for each new drug3. Environmental legislation also applies to pharmaceutical drugs. The basis for this is the European Water Framework Directive implemented in national law, for instance in the German Water Resources Act (WHG). Ecotoxicity tests test the harmful effects on organisms in the environment (aquatic organisms, as well as soil and sediment organisms)10, 11.

Ecotoxicology and methods

If one were able to produce “green pills” that were proven to be completely biodegradable, a multitude of ecotoxicological tests would also be unnecessary, tests that often use fishes, for instance early developmental stages of zebrafish, trout or carp for the aquatic environment, and birds such as quails, ducks or pigeons for the terrestrial environment. At present only the quality of industrial effluents is tested solely using an alternative method that employs fish eggs12 instead of adult animals. This is regulated in the “Verordnung über Anforderungen an das Einleiten von Abwasser in Gewässer (AbwV)” [German ordinance on introducing effluents to bodies of water] as of 17.06.2004, latest amendment as of 05.09.2014. This is not the case with the production of chemical or pharmaceutical products.

In ecotoxicological tests for drugs for human consumption, the “predicted environmental concentration”c and the environmental impact are determined, after which in phase 2A a physicochemical analysis and effect studies are conducted10. These tests use organisms such as small crustaceans (Daphnia) in a reproduction test in accordance with OECD Test Guideline 211 and fishes (early life stage) in accordance with OECD Test Guideline 210. The species recommended for use is the zebrafish, but the tests can also be conducted on Japanese rice fish, three-spined stickleback or trout in order to determine the no-observed-effect-concentration (NOEC)d or the PNECe. If no risk is determined in phase 2A, further tests are conducted (phase 2B), e.g. on bacteria and soil organisms13, 14.

The following aquatic organisms are used in tests for veterinary drugs15. For the fresh water environment, e.g. rivers and lakes, Daphnia are used in the Acute Immobilisation Test (OECD Test Guideline 202), and fishes in the Acute Toxicity Test (LC50)f (Test Guideline 203).

For marine habitats, copepods (Cyclops) or other crustaceans are used in the Acute Toxicity Test (EC50, ISO 14669), as well as fishes in the Acute Toxicity Test (LC50) (Test Guideline 203).

Mutagenicity and genotoxicity tests

Producers of new, „green" pharmaceutical molecules must also conduct a test for potential contamination according to the requirements of the ICH (International Conference on Harmonisation)16, 17. To this end, mutagenicity and genotoxicological tests are conducted, such as the Ames test – a bacterial test according to OECD Test Guideline 471 –  and an in vitro metaphase chromosome aberration test according to OECD Test Guideline 47318. The aim of the tests is to rule out reactions between small molecules and DNA that could lead to mutations. In the Ames test, the bacteria have lost the ability to synthesise histidine. The test substance triggers a reverse mutation in the bacteria, allowing them once again to synthesise histidine on their own. Although both tests are in vitro tests, in the Ames test, liver microsomes from rats are added in a mixture known as “S9 fraction”, in order to maximise the reaction.

If the results of the in vitro studies positive, two further studies must be conducted in vivo. In that case mammal cells are used, for instance in the micronucleus test using mice.

„… Our central approach is the concept Benign by Design …“

Professor Dr. Klaus Kümmerer is a member of several national and international commissions and committees, such as the Senate Commission on Water Research of the German Research Foundation DFG (Deutsche Forschungsgemeinschaft), representative of the Gesellschaft Deutscher Chemiker (GDCh - German Chemical Society) in the management board of the EU technology platform SusChem Europe19 and member of the board in the division for sustainable chemistry (“Fachgruppe Nachhaltige Chemie”) in the Gesellschaft Deutscher Chemiker. He is also the editor and co-editor of several international science journals. Professor Kümmerer received the Swedish Recipharm International Environmental Award in 2009 for his research into pharmaceuticals in the environment and sustainable pharmacy.

InVitroJobs spoke with Prof. Kümmerer about water pollution by pharmaceutical drugs and his research into solutions for this set of problems.

InVitroJobs: What exactly do you research? What methods do you use?

Prof. Kümmerer: We research in an interdisciplinary and transdisciplinary setting within the Faculty of Sustainability, with national and international cooperations in the field of sustainable chemistry and pharmacy. We concentrate on ecological questions and sustainable approaches, including social and ecological aspects in the context of the life cycles of chemical substances and products. One focus of our work is investigating the retention and avoidance of organic substances in the environment and the evaluation of chemical substances.

To this end we use both experimental methods  and especially modern, computer-based methodsg. Our primary concern is how we can make organic substances more biodegradable when they enter the environment – before they are even produced and introduced to the market (“benign by design”, “design for the environment”). In addition to experimental methods in analytic chemistry, environmental chemistry and hydrology, we increasingly implement computer-based methods (Structure-property relationshipsh, dockingi, dispersion modellingj).

We investigate the introduction (for instance identifying relevant sources), and the dispersion and behaviour (e.g. biological and photochemical degradation) of chemical substances in the aquatic environment in the sense of sustainable water management. We are therefore very interested in documenting the effects (e.g. genotoxicity, mutagenicity, bacterial toxicity). At present it is especially pesticides, pharmaceuticals and textile processing aids that are at the centre of our work. The task at hand is to concentrate on possible problematic consequences that may occur in tap water and sewage purification or the aquatic environment, for instance as the result of an incomplete degradation of the pertinent substances (transformation products stable against degradation).

A vital question in this regard is how to take into consideration reduced environmental pollution by chemicals, pharmaceuticals and products that contain them at the very beginning of their product life cycles. This requires a comprehensive understanding of functionality and the environmental properties of chemical substances and products. Our central approach is the concept “benign by design”. This means the targeted design of new chemicals and pharmaceuticals even before they are synthesised, so as to achieve sustainable functionality.

InVitroJobs: What insights have you gained?

Prof. Kümmerer: Chemical substances need not be stable per se or in all circumstances. Rather there are stages at which the substances must be stable – under the predominant conditions at that stage – and others in which they must be unstable, that is to say completely mineralisable. The key is that we do not approach the task from a marketing perspective, that is with a view to the stability of substances or even a maximisation thereof, but in the best chemical sense with reactivity in mind: where and under what conditions must a substance be stable and where doesn’t it have to be?

InVitroJobs: What does “benign chemicals” mean?

Prof. Kümmerer: It means chemicals and pharmaceuticals with properties designed to best fulfil their functions (efficacy, environmental behaviour, etc.). Before they are synthesised for the first time, sustainable functionality should be achieved, along with faster and complete biodegradability after they enter the environment. This should allow resulting problems to be avoided.

InVitroJobs: What are the prospects for bodies of water at present? What is the core problem?

Prof. Kümmerer: The core problem from a chemical point of view is – unlike earlier – pollution by a multitude of substances in low concentrations (“trace substances”), as well as products that are not completely broken down in purification plants and bodies of water.

InVitroJobs: Why are residues from sewage so dangerous? Substances excreted in urine are water-generally soluble, isn’t that enough? Why don’t the substances break down any further?

Prof. Kümmerer: What is “dangerous” is the multitude of substances and their partly unknown properties. As there are so many substances with partly unknown degradation products, a real risk assessment will probably never be possible. In the end it is these substances that prevent sustainable water resource management.

InVitroJobs: How can you make a substance more biodegradable?

Prof. Kümmerer: If you know what parts of a molecule promote biodegradability in purification plants or in the environment and under what conditions, you can make use of this and deliberately incorporate such groups in molecules.

InVitroJobs: Why does the industry hesitate to address this? After all, ecotoxicology is part of risk assessments. That should make it attractive.

Extract from the result of a computer-based calculation: The molecule parts marked red are those responsible for the desired property (e.g. a certain toxicity or a lack of degradability). This lets the scientist know and check for the reason for the molecule’s or substance’s property. The molecule can then be altered at that site if needed, resulting in a newly-designed (benign) molecule.
Photo: Copyright: Leuphana University Lüneburg.

Prof. Kümmerer: New concepts always mean rethinking – and in that respect we are all conservative to start off with. In addition, when using new chemical substances, production processes and product compositions may need to be changed and new product approvals may be necessary. A short-term perspective does not have its sights on medium-term or long-term market chances, but sticks to the conventional.

InVitroJobs: What possibilities can you offer students who want to complete their master thesis in your institute? What qualification must they have?

Prof. Kümmerer: We have a number of different approaches to issues in sustainable chemistry and pharmacy – from the specific investigation of the breakdown of substances through the implementation of cheminformatics methods, analytical chemistry and environmental chemistry to questions such as how to achieve greater acceptance of the concept “benign by design”. This means that the possible initial qualifications are correspondingly diverse: from chemistry and pharmacy and their subdisciplines to human and social sciences.

What is important in any case is an openness to unconventional ideas and interdisciplinary work. For this reason we research in an interdisciplinary and transdisciplinary setting in the Faculty for Sustainability. To this end we have national and international partnerships.

InVitroJobs: How do you think ecotoxicological research and animal-free research could be advanced?

Prof. Kümmerer: Better acceptance and a better understanding of the possibilities and boundaries of computer-based methods would be an important building block.

InVitroJobs: Thank you for the interview.


a Mutagenicity: Hereditary changes in genetic material
b Genotoxicity: A  substance damages a cell’s genetic material, thus influencing cellular integrity.
c Predicted Environmental Concentration (PEC): Calculated value of a chemical in the environment based on exposure models.
d No-observed-effect-concentration (NOEC): The concentration of a  test substance at which no damaging effect can be determined.
e PNEC (Predicted no effect concentration): Predicted concentration of a substance at which no environmental effects  are observed.
f LC50 (Lethal Concentration 50): die concentration of a substance at which 50 per cent of the test organisms died.
g Computer-based methods: In silico methods (e.g. QSAR) for calculating the properties of chemicals and pharmaceutical drugs, design of benign chemicals. Prediction of cytotoxicity, genotoxicity, occurrence, fate and effects of chemicals and pharmaceuticals in the aquatic environment.
h Structure-property relationship: Relationship  between a pharmaceutical, chemical, biological or physical property of a molecule and its chemical structure. simple examples are to be found in the names of substance groups with similar properties, for instance alcohols or aldehydes20.
i Docking (also known as “molecular docking”): a method that predicts the preferred orientation of one molecule to a second one when bound to each other to form a stable complex.
j Dispersion modelling: computer-modelling of the dispersion of chemical substances, in this case in aquatic systems.

Benign molecules: The term “benign” is familiar from medicine: Unlike malignant (harmful) tumours, benign tumours are those that display no tendency to aggressive proliferation or exacerbation. It is the same with molecules (e.g. pharmaceutical drugs): they are “constructed” so as to best fulfil the requirements (healing or alleviation), whilst keeping the environmental hazards as low as possible. The molecules should also be quickly and completely degradable.

Literature and websites:

6 Damstra, T, Barlow, S, Bergman, A, Kavlock, R & Van der Kraak, G (2013): Global assessment of the state-of-the-science of endocrine disruptors. WHO, IPCS International Program on Chemical Safety. WHO/PCS/EDC/02.2
7 Klaminder, J., Jonsson, M., Fick, J., Sundelin, A. & Brodin, T. (2014): The conceptual imperfection of aquatic risk assessment tests: highlighting the need for tests designed to detect therapeutic effects of pharmaceutical contaminants. Environ. Res. Lett. 9. doi:10.1088/1748-9326/9/8/084003.
12 DIN EN ISO 15088 (2009-06): Water quality - Determination of the acute toxicity of waste water to zebrafish eggs (Danio rerio) (ISO 15088:2007); German version EN ISO 15088:2008
14 European Medical Agency: Questions and Answers on 'Guideline on the Environmental Risk Assessment of Medicinal Products for Human Use' (2010) EMA/CHMP/SWP/44609/2010
15 EMEA, Committee for Medicinal Products for Veterinary Use (CVMP) (2003): Guideline on Environmental Impact Assessment for Veterinary Medicinal Products Phase II. CVMP/VICH/790/03-Final.
16 International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (2006): ICH Harmonised Tripartite Guideline Impurities in new Drug Substances Q3A(R2). Geneva.
17 International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (2011): ICH Harmonised Tripartite Guideline Guidance on Genotoxicity Testing and Data Interpretation for Pharmaceuticals Intended for Human Use S2(R1). Geneva.

The 12 principles of Green Chemistry:

Sharon Munn & Marina Goumenou (2013): Key scientific issues relevant to the identification and characterisation of endocrine disrupting substances. Report of the Endocrine Disrupters Expert Advisory Group. JRC Scientific and Policy Reports. European Commission EUR 25919 – Joint Research Centre – Institute for Health and Consumer Protection.