The ecotoxicological assay is a biological experiment that verifies whether an environmental sample, or a potentially toxic compound, causes a relevant biological response in the organisms used for the test. The ultimate goal is therefore to understand if there is a threat to the conservation of the functional integrity of ecosystems.
Ecotoxicology: the rationale behind the tests
The measurement of the ecotoxicity of environmental samples is performed through a series of test that use different target organisms that are usually exposed to different concentrations or doses of a test substance or sample (wastewater, waste, sewage sludge, soil, river or marine sediment) diluted in a suitable medium.
Ecotoxicological analyzes in waters
Tests in aqueous matrices (surface or groundwater and wastewater) and eluates are carried out according to official ISO and OECD methods and guidelines. In particular:
• Algal growth inhibition with UNI EN ISO 8692 (in fresh water) and UNI EN ISO 10253 (in marine waters and eluates);
- Acute toxicity with Artemia Salina;
- Acute toxicity with Daphnia Magna (UNI EN ISO 6341) in fresh water, drains and eluates;
- Acute toxicity with Vibrio Fischeri according to UNI EN ISO 11348.
Ecotoxicological tests in soils and sediments
The tests are carried out with:
- Vibrio Fischeri, acute toxicity according to UNI EN ISO 11348;
- Seawater algae, inhibition of algal growth according to UNI EN ISO 10253;
- Acartia tonsa, mortality test after 7 days of exposure MU 2366.
As regards the tests required by Italian Legislative Decree no. 152/06 (ecotoxicological tests to control industrial and civil wastewater and sediments of inland waters):
- Acute toxicity test with Daphnia magna UNI EN ISO 6341;
- Bioluminescence inhibition test with Vibrio fischeri UNI EN ISO 11348-3;
- Acute toxicity test with Artemia Salina.
Ecotoxicological tests on waste
This type of waste analysis allows the attribution of waste hazard classes: HP4 IRRITANT, HP8 CORROSIVE, HP14 ECOTOXIC. In the attribution of these classes, the legislation considers that an evaluation based on the execution of some specific tests is a priority over an evaluation based on stoichiometric calculations.
On waste, we therefore propose the tests for the classification of waste provided for by Reg. EC n. 440/2008:
- 24 and 48 h acute toxicity test with Daphnia magna OECD 202;
- Acute toxicity test on fish embryos (FET) OECD 236;
- Acute toxicity test with Pseudokirchneriella subcapitata OECD 201.
For the purpose of attributing / excluding the hazardous characteristics HP8 (Corrosive) and HP4 (Irritant – Skin irritation and eye lesions) as per Regulation no. 1272/2008 (CLP), in vitro tests for corrosivity and irritation on specific cell lines and on reconstituted human tissues are also performed.
Ecotoxicological tests on chemical substances and preparations
The acute toxicity assays and tests are also carried out directly on chemicals for which this evaluation has to be carried out.
Ecotoxicological checks are performed on the compost by carrying out the germination test using watercress (UNI 10780). Germination and root elongation tests are carried out on water, mud and sediments using sorghum, cucumber or watercress according to UNI 11357.
Mérieux NutriSciences: a complete ecotoxicological test service
Mérieux NutriSciences offers a wide range of specific tests to assess the potential risk of pollutants, waste, products and substances in ecosystems.
Laboratory studies are carried out on plants, algae and crustaceans and cover the testing needs required by current legislation.
Where possible, ecotoxicological studies are accompanied by tests to verify the concentration and stability of the test substance in the sampling system.