Ecotoxicity tests
Mar 23, 2015
Compounds of natural or anthropic origins can impact the environment, even if they are present at very low concentration. The list of compounds is very long and new ones appear almost every day – several hundreds of thousands can be distinguished. To mention but a few, pesticides, detergents and drugs are typical classes for ecotoxicology tests.
At ALS Life Sciences, our Department of ecotoxicology routinely tests:
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Waste leachate, wastewater
Very often, several compounds are present simultaneously or the mixture of pollutants is not known. In this case, ecotoxicity tests have the advantage to integrate the effects of all contaminants present in an effluent/leachate and their interaction between them or with the other constituents of the effluent/leachate.
Aquatic Ecotoxicity
| Organism | Determination |
Effect criteria |
Exposure time |
| Poecilia reticulata (fish) | Acute lethal toxicity of substances on freshwater fish | Mortality inhibition LC50 | 48 hours, 96 hours |
| Daphnia magna (daphnids) | Acute inhibition of the mobility of Daphnia magna | Mobility inhibition EC50 | 48 hours |
| Vibrio Fischeri (bacteria) | Acute inhibitory effect of water samples on the light emission of Vibrio Fischeri | Light emission inhibition EC50, EC20 | 15 min, 30 min |
| Desmodesmus subspicatus (algae) | Acute inhibition of algal growth of unicellular green algae | Growth inhibition EC50 | 72 hours |
| Sinapis alba (white mustard) | Acute inhibition of root growth of white mustard | Growth inhibition IC50 | 72 hours |
| Lemna minor (duckweed) | Acute inhibition of root growth of lesser duckweed | Growth inhibition EC50 | 7 days |
Chemical substances, drugs, Pharmaceutical products
Ecotoxicity tests are also of precious help in the frame of legal ratification of chemical substances and in the evaluation of toxicity to the environment of Pharmaceutical products or their mixtures.
Phytotoxicity tests
Seeds of Lepidium sativum (garden cress) are exposed to the test substance for a period of 48 hours. The system responses are the reduction of root growth and seed germination. The results are evaluated in order to calculate the germination index.
Microtox test
The natural light emission of bioluminescent bacteria, Vibrio Fischeri, is measured. The inhibition of the light emission in the presence of the sample is determined against a non-toxic check sample. The results are evaluated in order to calculate the EC50 (concentration which causes 50% inhibition of light emission).
The common application of Microtox is for testing of complex chemical mixtures such as effluents, leachates or even new chemical substances for assessing of their impacts or minimizing them. The test is accepted as a standard test in a number of countries including United Kingdom, Germany, Sweden and the Netherlands.
Contaminated soils, waste – terrestrial ecotoxicity
The problematic of contaminated soils and solid waste – in constant growth worldwide – is the driving force behind the increasing needs of toxicological characterization on terrestrial organisms. Invertebrates, such as worms, and plants, such as lettuce, are considered as good indicators of soil quality.
| Organism | Determination | Effect criteria | Exposure time |
| Folsomia candida (springtail) | Inhibition of reproduction of springtails (Folsomia candida) by soil contaminants | Inhibition of reproduction EC50 | 28 days |
| Enchytraeus crypticus (pot worm) | Inhibition of reproduction of pot worms (Enchytraeus crypticus) by soil contaminants | Inhibition of reproduction EC50 | 28 days |
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Lactuca sativa (lettuce) |
Inhibition of root growth of lettuce by soil contaminants | Growth inhibition EC50 | 120 hours |
For more information, do not hesitate to contact your ALS Life Sciences representative.
