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Comparison of short‐term chronic and chronic silver toxicity to fathead minnows in unamended and sodium chloride‐amended waters
Author(s) -
Naddy Rami B.,
Rehner Anita B.,
McNerney Gina R.,
Gorsuch Joseph W.,
Kramer James R.,
Wood Chris M.,
Paquin Paul R.,
Stubblefield William A.
Publication year - 2007
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 - 10.1897/06-638r.1
Subject(s) - chronic toxicity , toxicity , toxicant , chemistry , sodium , silver nitrate , acute toxicity , toxicology , environmental chemistry , zoology , nuclear chemistry , biology , organic chemistry
The chronic (early life stage [ELS]) and short‐term chronic (STC) toxicity of silver (as silver nitrate) to fathead minnows (FHM) was determined concurrently in flow‐through exposures (33 volume additions/d). Paired ELS (∼30 d) and STC (7 d) studies were conducted with and without the addition of 60 mg/L Cl (as NaCl). The paired studies in unamended water were later repeated using standard flow conditions (9 volume additions/d). The purpose of the paired studies was to determine if short‐term chronic endpoints can be used to predict effects in ELS studies. For each experiment, a “split‐chamber” design (organisms were held in a common exposure chamber) allowed the direct comparison between short‐term and chronic exposures. It appeared that the chronic toxicity of silver was mitigated to some extent by NaCl addition. The maximum acceptable toxicant concentration for growth in the ELS study was 0.53 μg dissolved Ag/L under standard flow conditions. Early life stage and STC endpoints in all three studies typically agreed within a factor of two. Whole‐body sodium and silver concentrations measured in individual fathead minnows during these studies showed an increase in silver body burdens and a decrease in sodium concentration. These results indicate that the STC study could be used as a surrogate test to estimate chronic toxicity and that the mechanism of chronic silver toxicity may be the same as for acute toxicity.