US EPA

1494719 

Journal Article 

Assessing the Effects of the Safety Concentrations of Some PAHs on the Aquatic Biocoenosis 

Zaleska-Radziwill, M; Lebkowska, M; Kalinowski, R 

2008 

30 

4 

19-28 

WOS:000261983800003 

http://://WOS:000261983800003
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The effects of the so-called safety concentrations on the
aquatic biocoenosis in a model laboratory microcosm ecosystem were verified for the following
PAHs of choice: naphthalene, phenanthrene, anthracene and pyrene. The safety concentrations were
calculated using the results of laboratory single species toxicity tests. Structural and
functional changes in the aquatic ecosystem were assessed by quantitative and qualitative
analysis of the phyto- and zooplankton, bottom sediment, vascular plant growth, enzymatic
reactions, as well as microbiological and physicochemical parameters. During the final period of
the experiments algae growth was observed, primarily of the chlorophyta Scenedesmus quadricauda
and Selenastrum capricornutum, and in some samples also Chlorella vulgaris. The experimental
conditions applied favored a high growth of Heterocypris inconguretus and Brachionus
calyciflorus. NoPAH-influenced deaths were found to occurin the fish species Lebistes
reticulatus. Microscopic examinations of the bottom sediment have revealed the presence of
numerous protozoa both in the controls and in the PAH containing samples. Enzymatic activity of
the bottom sediment fluctuated in the course of the experiments, according to the inflow of the
food substrate coming from the atrophy of the organisms. Microbiological examinations make it
clear that between the 14th and 42nd day of the test the number of bacteria in the water
decreased by an order of magnitude in all the samples as compared to the number determined within
the first 7 days. Summing up, the results obtained from a 42-day experiment conducted in a model
aquatic ecosystem have demonstrated that the safety concentrations of the PAHs chosen, which were
established in the course of single species toxicity tests, exert no adverse effect either on the
structure or on the functionality of the aquatic biocoenosis. 

PAH; naphthalene; phenanthrene; anthracene; pyrene; safety concentration; aquatic biocoenosis; microcosm