Toward Validation of Toxicological Interpretation of Diffusive Gradients in Thin Films in Marine Waters Impacted by Copper

Abstract

Determination of the median effective concentration (EC50) of Cu on Mytilus galloprovincialis larvae by diffusive gradient in thin films (DGT) has been shown to effectively reduce the need to consider dissolved organic carbon (DOC) concentration and quality. A standard toxicity test protocol was used to validate previously modeled protective effects, afforded to highly sensitive marine larvae by ligand competition, in 5 diverse site waters. The results demonstrate significant narrowing of M. galloprovincialis toxicological endpoints, where EC50s ranged from 3.74 to 6.67 μg/L as CDGT Cu versus 8.76 to 26.8 μg/L as dissolved Cu (CuDISS) over a DOC range of 0.74 to 3.11 mg/L; Strongylocentrotus purpuratus EC50s were 10.5 to 19.3 μg/L as CDGT Cu versus 22.7 to 67.1 μg/L as CuDISS over the same DOC range. The quality of DOC was characterized by fluorescence excitation and emission matrices. The results indicate that the heterogeneity of competing Cu binding ligands, in common marine waters, minimizes the need for class determinations toward explaining the degree of protection. Using conservative assumptions, an M. galloprovincialis CDGT Cu EC50 of 3.7 µg/L and corresponding criterion maximum concentration CDGT Cu of 1.8 µg/L, for universal application by regulatory compliance‐monitoring programs, are proposed as a superior approach toward both integration of dynamic water quality over effective exposure periods and quantification of biologically relevant trace Cu speciation. Environ Toxicol Chem 2020;39:873–881. © 2020 SETAC

Field application of a novel active-passive sampling technique for the simultaneous measurement of a wide range of contaminants in water

“…DGT-Cu concentrations were 31 and 34% of dissolved concentrations for 8 and 15 day deployments, respectively. This was in agreement with previous speciation analysis performed in this location (Gaulier et al, 2019), and consistent with the reduced lability of copper due to the presence of relatively strongly complexing organic ligands (Macoustra et al, 2019;Strivens et al, 2020). DGT-Mn and -Zn concentrations were 13~19%, and 47~57% lower than dissolved zinc concentrations measured in DWS, respectively.…”

Comparison between the toxicity of Copper and Irgarol 1051 as two different generations of antifoulings on growth and essential metabolites of marine algae (Dunaliella salina as a case study)

“…Copper is an essential element for all living organisms and play important roles in many metabolic processes (Ochoa-Herrera et al, 2011). However, copper may also be toxic to most species when concentrations exceed levels that are physiologically required (Strivens et al, 2020).…”

Inputs of Total and Labile Dissolved Metals from Six Facilities Continuously Discharging Treated Wastewaters to the Marine Environment of Gran Canaria Island (Canary Islands, Spain)

“…DGT-labile metal concentrations may represent the bioavailable metal fraction more accurately than filterable metal or total metal [ 23 , 24 ]. Therefore, it has been suggested that DGT-labile metal concentrations might represent the “potentially bioavailable” metal fraction to the biota [ 25 , 26 ].…”