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- Title
PREDICTION OF WATER POLLUTION LEVEL USING ACUTE TOXICOLOGICAL TESTS.
- Authors
Hoxha, Belinda; Osmani, Marilda; Mazrreku, Armela
- Abstract
Water pollution can be defined as the accumulation in high quantity of chemical, biological and physical materials in water bodies, which might destroy the quality of water life. There are a wide range of pollutants that alter the natural water parameters. Environmental toxicology is a multidisciplinary field that deals with the study of the adverse effects of various chemical, biological and physical agents in living terrestrial/water organisms. Ecotoxicology deals with the study of the adverse effects of chemical toxicants in the population and in different levels of ecosystem. A living organism might be exposed toward a specific toxicant in different stages of its life cycle. The toxicity might differ when considering the given organism in within its food web. Bioaccumulation occurs when the organism accumulates the toxicants in its fatty tissues. This process is usually limited in the areas affected by the environmental toxicants. The adverse effects of such chemical agents might influence a specific organism or its whole community and thus decreasing the species diversity. Ecotoxicological studies use living organisms to predict the effects of different chemicals in various environments, including water systems. Water toxicology is the study of the effects of anthropogenic chemicals on water organisms. Some non-volatile compounds might be soluble in water and thus the water organisms are exposed to them. Acute and chronic toxicity tests are performed for different living organisms. Daphnia is one of many ecologically important species of fresh water systems. It can be reproduced with parthenogenesis in optimal conditions, but during the periods with less food supplies and during the cold period of time, males appear in the offspring and the sexual reproduction occurs. In laboratory continuously optimal conditions only female organisms can be born, and making thus possible to have a genetically identical population. Daphnia sp. is one of the organisms used to foresee the possible impact of the chemicals in water bodies. This study takes in consideration the acute tests using Daphnia sp, as an indicator of possible effects in water of different concentrations of nickel solutions. These organisms, which are natural inhabitants of water systems, are raised in laboratory conditions in accordance with their natural habitat. Various nickel concentrations are used to test Daphnia behavior and mortality. During the acute tests the living organisms of less than 24 hours of life are exposed to nickel solutions for a period of time not more than 24 hours. The acute test goal is to find the chemical concentration that immobilizes 50% of the tested organisms in 24 hours. These tests are performed according to OECD guides and standards. The laboratory data are then elaborated in order to determine the highest concentration of the chemical that shows the highest mortality of the organisms, as well as the lowest concentration with no effect in the population. Experiments show that Daphnia organisms exhibit various behaviors in different chemical concentrations.
- Subjects
WATER pollution; TOXICITY testing; BODIES of water; WATER quality; ENVIRONMENTAL toxicology
- Publication
Knowledge: International Journal, 2020, Vol 42, Issue 3, p513
- ISSN
2545-4439
- Publication type
Article