Small traces, large impact

Already some time ago we participated in writing an article on Anthropogenic Trace Compounds (ATCs). ATCs are an issue for water quality, since they increased in numbers and concentrations over the last years. This very heterogenous group of chemicals is a major challenge for research and policy making, in regards of identification, detection, monitoring, fate, toxicity and mitigation. They represent a complex network of interrelations of physical-chemical properties and behaviour, and biological activity. Literally, the substances only have in common that they are introduced into the water cycle by humanity, are found at still rather low concentrations, but anyway represent a potential danger for human and environmental health.

Together with our colleagues we reviewed current trends monitoring and management, and identified innovative and effective strategies as well as knowledge gaps and urgent needs. We highlight the lack of generally accepted indicator substances as one major issue that has to be solved for future monitoring. Also, we advocate for the implementation of effect-based tools in water monitoring, and for an appropriate risk assessment of ATCs.

There's a whole lot more to find in this comprehensive review article. Read the entire story about "Anthropogenic Trace Compounds (ATCs) in aquatic habitats — Research needs on sources, fate, detection and toxicity to ensure timely elimination strategies and risk management". And you really can read it, it's Open Access!

The EDA guide to surviving environmental analysis

Colleague Werner Brack at the UFZ in Leipzig, Germany is an outstanding expert on effect-directed analysis (EDA). EDA stands for an analytical approach that uses chemical and biological analysis to identify single contaminants as the culprits for toxicity in environmental samples.

It combines the best of both worlds. The ability to detect effects and the power to identify as well as elucidate molecule structures are interconnected by a sophisticated fractionation. The EDA principle is easily explained: (1) samples are tested for their effects in one or more bioassays, (2) effective samples are fractionated and fractions tested again, (3) effective fractions are further fractionated and tested, and finally (4) the substances in the few remaining effective fractions are chemically identified.

While sounding quite easy, EDA can be highly complex effort, due to the multitude of options for experimental design. Which bioassays should be used for screening, which biological effect should be targetted? How to properly fractionate the samples, for a most succesful separation of the compounds of interest? What techniques and methods are suitable for structure identification and elucidation?

These and many other crucial questions form a seemingly uncontrolled network of possibilities, that makes EDA a major challenge in environmental toxicology and chemistry. Werner however set out to tame this beast. He invited a large number of colleagues to write a comprehensive overview article about all aspects involving and impacting experimental design in EDA. We were among the lucky ones he asked to contribute to "Effect-directed analysis supporting monitoring of aquatic environments — An in-depth overview".

Cooperation for an effect-based investigation of municipal waste waters

Its not happening often that ecotoxicologists are asked by a municipality to investigate their sewage waters. The City of Stolberg together with Wasserverband Eifel-Rur (WVER) did, and we agreed to give 10 samples from their sewage water system a thorough ecotoxicological look, including influents and effluents from the waste water treatment plant Stolberg-Steinfurt.

This small but very interesting project will be covered by the master's thesis of candidate Sarah Johann. We will apply a range of different bioassays to reveal any possible hazardous potential.
Stolberg is a city near Aachen and an industrial hotspot of the region. While they have extensive data on heavy metal concentrations from continuous monitoring, so far no in-depth investigation of organic contamination has been done. Our bioassays are very well suited and sensitive enough to detect such substances through their biological activity.

Any positive results we will gain do not necessarily indicate a problem at all. Concentrations traceable using bioassays are often well below any environmentally or even toxicologically relevant level. Also, we do not expect any severe findings. This is a completely unbiased study, driven by scientific curiosity.

The City of Stolberg and the WVER are just very strict regarding environmental and human safety. They do so much for quality assurance when it comes to their waste waters, they now also want to cover this aspect. For us the project is a fantastic opportunity to get access to well-defined, specific waste water samples from different, very interesting spots, to better understand distribution of contaminants along the sewage water flow, and to prove bioassays as valuable tools for waste water monitoring.

Micronucleus assay goes robotics

In future our micronucleus assay (MNC) will run semi-automatically using a slideloader and a software-controlled automatic stage attached to a fluorescence microscope with a camera. Together with Nikon GmbH and Prior Scientific Instruments GmbH we successfully tested this combination as a measure for a dramatic increase in sample throughput of the MNC. Furthermore this allows to have well documented MNC results. For several cell types also a software-based evaluation should be feasible.

The equipment is the most recent addition to the high-end technology facilities in our Students Lab Fascinating Environment. Nikon as well as Prior are partners of this fruitful academia-industry initiative. We also produced a movie clip showing the equipment at work. I will link it here soon.