Bioaccumulation of selenate, selenite, and seleno-DL-methionine by the brine fly larvae Ephydra cinerea Jones

Autor: T. N. Rosetta, Allen W. Knight
Rok vydání: 1995
Předmět:
Zdroj: Archives of Environmental Contamination and Toxicology. 29:351-357
ISSN: 1432-0703
0090-4341
DOI: 10.1007/bf00212500
Popis: High concentrations of selenium threaten waterfowl at California San Joaquin Valley agricultural wastewater evaporation ponds. This study evaluates and compares two routes of Se exposure and uptake by third instar Ephydra cinerea (brine fly) larvae. A 48-h static bioconcentration bioassay provided information on the larval uptake of selenate, selenite, and seleno-DL-methionine (SeMet) at Se waterborne concentrations ranging from 10.0–20,000 ug/L. At equivalent concentration levels, SeMet was bioconcentrated to a greater extent than selenite, which was bioconcentrated more than selenate. Forty-eight-hour static bioconcentration vs. biomagnification bioassays allowed for comparisons of the two routes of exposure of selenate, selenite, and SeMet. Biomagnification was determined to be the primary Se uptake pathway, exemplified most notably in the selenite treatment. Measured agar-based food unit Se levels presented evidence that the uptake of selenite, and especially SeMet, by microbial populations was transferred to E. cinerea larvae as they scavenged for bacteria and yeast, etc. in the diet matrix. As a primary dietary item of waterfowl at evaporation ponds, E. cinerea in seleniferous waters presents a potentially high hazard.
Databáze: OpenAIRE
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