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Assessing the potential toxicity of resuspended sediment
Author(s) -
Bonnet Corinne,
Babut Marc,
Férard JeanFrançois,
Martel Louis,
Garric Jeanne
Publication year - 2000
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620190510
Subject(s) - daphnia magna , microcosm , sediment , environmental chemistry , hyalella azteca , environmental science , dredging , pore water pressure , water column , geology , ecology , chemistry , toxicity , oceanography , amphipoda , biology , crustacean , paleontology , organic chemistry , geotechnical engineering
Two moderately contaminated freshwater sediments (Sorel Harbour, St. Lawrence River, Canada) were subjected to a suspension event. The objective was to assess the environmental impact of the disposal of dredged material in water, in particular, the short‐term effects of dumping on the water column and the long‐term effects of dredged sediment deposits. In a series of microcosms, the sediments were left to stand for 25 d under flow‐through conditions (reference conditions). In a second series of microcosms, sediments were vigorously suspended for 15 min before being left to settle and were submitted to the same treatment as reference sediments during the following 25 d. Physicochemical and biological parameters ( Daphnia magna and Hydra attenuata survival) were measured in overlying water throughout the experiment. Sediment toxicity was assessed with Chironomus tentans and Hyalella azteca exposed to sediments collected at both the beginning and end of the 25‐d period. Pore‐water toxicity was evaluated with D. magna. During the suspension process, in the Sorel Harbour mixed sediment overlying water, we observed effects on H. attenuata survival and ammonia and metals (chromium, copper, and zinc) releases. Meanwhile, in reference (nonmixed) and mixed sediments as well as in associated pore waters, there were no significant chemical modifications nor biological effects after the 25‐d experiments. The developed approach, which attempts to simulate a dumping process, aims at allowing the assessment of the short‐ and long‐term hazards resulting from a resuspension process in overlying water and in resettled sediments using both chemical and biological measurements.