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A biodynamic understanding of dietborne metal uptake by a freshwater invertebrate

Environmental Science and Technology

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DOI: 10.1021/es7022913

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Abstract

Aquatic organisms accumulate metals from dissolved and particulate phases. Dietborne metal uptake likely prevails in nature, but the physiological processes governing metal bioaccumulation from diet are not fully understood. We characterize dietborne copper, cadmium, and nickel uptake by a freshwater gastropod (Lymnaea stagnalis) both in terms of biodynamics and membrane transport characteristics. We use enriched stable isotopes to trace newly accumulated metals from diet, determine food ingestion rate (IR) and estimate metal assimilation efficiency (AE). Upon 18-h exposure, dietborne metal influx was linear over a range encompassing most environmental concentrations. Dietary metal uptake rate constants (kuf) ranged from 0.104 to 0.162 g g -1 day-1, and appeared to be an expression of transmembrane transport characteristics. Although kuf values were 1000-times lower than uptake rate constants from solution, biodynamic modeling showed that diet is the major Cd, Cu, and Ni source in nature. AE varied slightly among metals and exposure concentrations (84-95%). Suppression of Cd and Cu influxes upon exposure to extreme concentrations coincided with a 10-fold decrease in food IR, suggesting that feeding inhibition could act as an end point for dietary metal toxicity in L. stagnalis.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
A biodynamic understanding of dietborne metal uptake by a freshwater invertebrate
Series title:
Environmental Science and Technology
DOI:
10.1021/es7022913
Volume
42
Issue:
5
Year Published:
2008
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
1801
Last page:
1806
Number of Pages:
6