Predicting toxicity of sediments spiked with silver

Abstract

Abstract-Previous experiments conducted with freshwater sediments spiked with silver have shown that, when expressed on a dry weight basis, the toxicity of silver is sediment-specific and dependent on the form of silver added (e.g., AgNO 3 , Ag 2 S). This study was conducted to assess the usefulness of silver interstitial water toxic units (IWTU) and acid volatile sulfide (AVS) concentrations in predicting the biological effects of silver species across sediments, regardless of the species of silver present. Two saltwater sediments were spiked with a series of concentrations of silver. The amphipod, Ampelisca abdita, was then exposed to the sediments in ten-day toxicity tests. Amphipod mortality was sediment-specific when expressed on a dry weight basis, but not when based on IWTU or simultaneously extracted metal (SEM)-AVS. Sediments with an excess of AVS relative to SEM had IWTU Ͻ0.5, and were generally not toxic. Sediments with an excess of SEM relative to AVS had silver IWTU Ͼ0.5, but no measurable AVS, and were generally toxic. Sediments with measurable AVS were not toxic. Reanalysis of the previously published data from the freshwater sediments spiked with silver showed mortality to be correlated with nominal SEM-AVS and with silver IWTU. Taken together, these results support the use of AVS and silver IWTUs in predicting the toxicity of silver in sediments.

Influence of reactive sulfide (AVS) and supplementary food on Ag, Cd and Zn bioaccumulation in the marine polychaete Neanthes arenaceodentata

“…This worm was chosen since it has a short life cycle, is easy to culture in the laboratory and has been used in many metal toxicity and bioaccumulation experiments (Reish 1985, Mason et al 1988, Pesch et al 1995, B. G. Lee et al 2000a. The 3 metals used in this study are characterized as highly toxic metals and have been studied for evaluation of AVS normalization approaches (e.g., , DeWitt et al 1996, Berry et al 1999.…”

An investigation into the effects of silver nanoparticles on natural microbial communities in two freshwater sediments

“…However, the proportion of formed Ag 2 S-NPs was determined by the concentration of AVS, redox state and nanoparticle property (Thalmann et al, 2014). Moreover, there can be extremely long equilibration times after spiking with AgNPs, and the transformation of AgNPs to Ag 2 S was reported uncompleted even after 18 months in natural environment (Berry et al, 1999;Lowry et al, 2012). In the present study, the initial AVS concentrations were 2.31 ± 0.15 and 0.75 ± 0.03 mmol/g in DL and LSL, respectively, and the AVS concentrations maintained stable during the 45-day exposure (Fig.…”

The Environmental Chemistry and Toxicology of Silver

“…The toxicity of silver to benthic organisms is controlled in part by sedimentary sulfides. Using Ag ϩ to spike sediments that have an excess of acid-volatile sulfide generally renders the sediments nontoxic [5]. Five papers [6][7][8][9][10] focus on the toxicity of silver to aquatic organisms, especially to fish, while the final manuscript [11] reviews the bioaccumulation and toxicity of silver compounds.…”

“…The next two papers focus on the environmental chemistry of silver, including a review of silver-sulfur compounds [2] and the importance of colloidal and acid-volatile sulfide fractions of aqueous silver at an old mining site [3]. Call et al [4] and Berry et al [5] report experiments on the toxicity of silver in sediments. The toxicity of silver to benthic organisms is controlled in part by sedimentary sulfides.…”