Can supervise: YES
Egodawatta, LP, Holland, A, Koppel, D & Jolley, DF 2020, 'Influence of Soil Phosphate on the Accumulation and Toxicity of Arsenic and Antimony in Choy Sum Cultivated in Individually and Co-contaminated Soils', ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, vol. 39, no. 6, pp. 1233-1243.View/Download from: Publisher's site
Egodawatta, LP, Holland, A, Koppel, D & Jolley, DF 2020, 'Interactive effects of arsenic and antimony on Ipomoea aquatica growth and bioaccumulation in co-contaminated soil', ENVIRONMENTAL POLLUTION, vol. 259.View/Download from: Publisher's site
Koppel, DJ, King, CK, Brown, KE, Price, GAV, Adams, MS & Jolley, DF 2020, 'Assessing the Risk of Metals and Their Mixtures in the Antarctic Nearshore Marine Environment with Diffusive Gradients in Thin-Films.', Environmental Science and Technology (Washington), vol. 54, no. 1, pp. 306-315.View/Download from: Publisher's site
Robust environmental assessments and contaminant monitoring in Antarctic near-shore marine environments need new techniques to overcome challenges presented by a highly dynamic environment. This study outlines an approach for contaminant monitoring and risk assessment in Antarctic marine conditions using diffusive gradients in thin-films (DGT) coupled to regionally specific ecotoxicology data and environmental quality standards. This is demonstrated in a field study where DGT samplers were deployed in the near-shore marine environment of East Antarctica around the operational Casey station and the abandoned Wilkes station to measure the time-averaged biologically available fraction of metal contaminants. The incorporation of DGT-labile concentrations to reference toxicity mixture models for three Antarctic organisms predicted low toxic effects (<5% effect to the growth or development of each organism). The comparison of metal concentrations to the Australian and New Zealand default water quality guideline values (WQGVs) showed no marine site exceeding the WQGVs for 95% species protection. However, all sites exceeded the 99% WQGVs due to copper concentrations that are likely of geogenic origin (i.e., not from anthropogenic sources). This study provides evidence supporting the use of the DGT technique to monitor contaminants and assess their environmental risk in the near-shore marine environment of Antarctica.
Macoustra, GK, Jolley, DF, Stauber, J, Koppel, DJ & Holland, A 2020, 'Amelioration of copper toxicity to a tropical freshwater microalga: Effect of natural DOM source and season', Environmental Pollution, vol. 266.View/Download from: Publisher's site
© 2020 Elsevier Ltd Australian tropical freshwaters can experience extreme seasonal variability in rainfall and run off, particularly due to pulse events such as storms and cyclones. This study investigated how seasonal variability in dissolved organic matter (DOM) quality impacted the chronic toxicity of copper to a tropical green alga (Chlorella sp.) in the presence of two concentrations of DOM (low: ∼2 mg C/L; high: ∼10 mg C/L) collected from three tropical waters. Copper speciation and lability were explored using diffusive gradients in thin-films (DGT) and modelled maximum dynamic concentrations (cdynmax) using data derived from the Windermere Humic Aqueous Model (WHAM VII). Relationships between copper lability and copper toxicity were assessed as potential tools for predicting toxicity. Copper toxicity varied significantly with DOM concentration, source and season. Copper toxicity decreased with increasing concentrations of DOM, with 50% growth inhibition effect concentrations (EC50) increasing from 1.9 μg Cu/L in synthetic test waters with no added DOM (0.34 mg C/L) up to 63 μg Cu/L at DOM concentrations of 9.9 mg C/L. Copper toxicity varied by up to 2-fold between the three DOM sources and EC50 values were generally lower in the presence of wet season DOM compared to dry season DOM. Linear relationships between DGT-labile copper and dissolved copper were significantly different between DOM source, but not concentration or season. Modelled cdynmax consistently under-predicted labile copper in high DOM treatments compared to DGT measurements but performed better in low DOM treatments, indicating that this method is DOM-concentration dependent. Neither speciation method was a good surrogate for copper toxicity in the presence of different sources of natural DOM. Our findings show that DOM source and season, not just DOM concentration, affect copper toxicity to freshwater biota. Therefore, DOM quality should be considered as a toxicity-modifying factor for f...
Engelsman, M, Snoek, MF, Banks, APW, Cantrell, P, Wang, X, Toms, L-M & Koppel, DJ 2019, 'Exposure to metals and semivolatile organic compounds in Australian fire stations', Environmental Research, vol. 179.View/Download from: Publisher's site
Koppel, DJ, Adams, MS, King, CK & Jolley, DF 2019, 'Diffusive Gradients in Thin Films Can Predict the Toxicity of Metal Mixtures to Two Microalgae: Validation for Environmental Monitoring in Antarctic Marine Conditions.', Environmental toxicology and chemistry, vol. 38, no. 6, pp. 1323-1333.View/Download from: Publisher's site
Anthropogenic contamination in the Antarctic near-shore marine environment is a challenge for environmental managers because of its isolation, high costs associated with monitoring and remediation activities, and the current lack of Antarctic-specific ecotoxicological data. The present study investigated the application of diffusive gradients in thin films (DGT) with a Chelex-100 binding resin for metal contaminant assessment in Antarctic marine conditions. Diffusion coefficients for cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn), determined at 1 °C, ranged between 2.1 and 2.6×10-6 cm2 /s and were up to 32% lower than those derived by theoretical calculations. Competition of metals on the DGT binding resin was observed at subsaturation concentrations, reducing the effective capacity for metal uptake by approximately 60%. The lability of the dissolved (0.45 µm filterable) Cd, Cu, Pb, and Zn metal fraction to DGT was generally >90% and unaffected by the presence of the Antarctic marine microalga Phaeocystis antarctica. Both DGT and dissolved metal concentrations gave equivalent mixture toxicity predictions in independent action and concentration addition models to P. antarctica and Cryothecomonas armigera; that is, predictions using DGT-labile concentrations also showed antagonism to P. antarctica, which agrees with previously determined mixture interactivity. The benefits of DGT over traditional sampling techniques (i.e., discrete water sampling) include lower method detection limits (MDLs), in situ assessment, and time-averaged concentrations which capture pulses of contamination typical of the Antarctic near-shore marine environment. The present study provides MDLs and recommended minimum deployment times to guide field deployments in Antarctica. Environ Toxicol Chem 2019;38:1323-1333. © 2019 SETAC.
Koppel, DJ, Adams, MS, King, CK & Jolley, DF 2019, 'Preliminary study of cellular metal accumulation in two Antarctic marine microalgae - implications for mixture interactivity and dietary risk.', Environmental pollution (Barking, Essex : 1987), vol. 252, no. Pt B, pp. 1582-1592.View/Download from: Publisher's site
Localised sites in Antarctica are contaminated with mixtures of metals, yet the risk this contamination poses to the marine ecosystem is not well characterised. Recent research showed that two Antarctic marine microalgae have antagonistic responses to a mixture of five common metals (Koppel et al., 2018a). However, the metal accumulating potential and risk to secondary consumers through dietary exposure are still unknown. This study investigates cellular accumulation following exposure to a mixture of cadmium, copper, nickel, lead, and zinc for the Antarctic marine microalgae, Phaeocystis antarctica and Cryothecomonas armigera. In both microalgae, cellular cadmium, copper, and lead concentrations increased with increasing exposures while cellular nickel and zinc did not. For both microalgae, copper in the metal mixture drives inhibition of growth rate with R2 values > -0.84 for all cellular fractions in both species and the observed antagonism was likely caused by zinc competition, having significantly positive partial regressions. Metal accumulation to P. antarctica and C. armigera is likely to be toxic to consumer organisms, with low exposure concentrations resulting in cellular concentrations of 500 and 1400 × 10-18 mol Zn cell-1 and 160 and 320 × 10-18 mol Cu cell-1, respectively.
Koppel, DJ, Adams, MS, King, CK & Jolley, DF 2018, 'Chronic toxicity of an environmentally relevant and equitoxic ratio of five metals to two Antarctic marine microalgae shows complex mixture interactivity.', Environmental pollution (Barking, Essex : 1987), vol. 242, no. Pt B, pp. 1319-1330.View/Download from: Publisher's site
Metal contaminants are rarely present in the environment individually, yet environmental quality guidelines are derived from single-metal toxicity data. Few metal mixture studies have investigated more than binary mixtures and many are at unrealistically high effect concentrations to freshwater organisms. This study investigates the toxicity of five metals (Cd, Cu, Ni, Pb, and Zn) to the Antarctic marine microalgae Phaeocystis antarctica and Cryothecomonas armigera. Two mixtures were tested: (i) an equitoxic mixture of contaminants present at their single-metal EC10 concentrations, and (ii) an environmental mixture based on the ratio metal concentrations in a contaminated Antarctic marine bay. Observed toxicity, as chronic population growth rate inhibition, was compared to Independent Action (IA) and Concentration Addition (CA) predictions parameterised to use EC10 values. This allowed for the inclusion of metals with low toxicities. The biomarkers chlorophyll a fluorescence, cell size and complexity, and intracellular lipid concentrations were assessed to investigate possible mechanisms behind metal-mixture interactions. Both microalgae had similar responses to the equitoxic mixture: non-interactive by IA and antagonistic by CA. Toxicity from the environmental mixture was antagonistic by IA to P. antarctica; however, to C. armigera it was concentration-dependent with antagonism at low toxicities and synergism at high toxicities by both IA and CA. Differences in dissolved organic carbon production and detoxification mechanisms may be responsible for these responses and warrants further investigation. This study shows that mixture toxicity interactions can be ratio, species, and concentration dependent. The responses of the microalgae to different mixture ratios highlight the need to assess toxicity at environmentally realistic metal ratios. Parameterising IA and CA reference models to use EC10s allowed for the inclusion of metals at low effect concentrations, whi...
Koppel, DJ, Gissi, F, Adams, MS, King, CK & Jolley, DF 2017, 'Chronic toxicity of five metals to the polar marine microalga Cryothecomonas armigera - Application of a new bioassay', ENVIRONMENTAL POLLUTION, vol. 228, pp. 211-221.View/Download from: Publisher's site
Wendling, LA, Binet, MT, Yuan, Z, Gissi, F, Koppel, DJ & Adams, MS 2013, 'Environmental toxicity and radioactivity assessment of a titanium-processing residue with potential for environmental use', ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, vol. 32, no. 7, pp. 1443-1452.View/Download from: Publisher's site
Wendling, LA, Binet, MT, Yuan, Z, Gissi, F, Koppel, DJ & Adams, MS 2013, 'GEOCHEMICAL AND ECOTOXICOLOGICAL ASSESSMENT OF IRON- AND STEEL-MAKING SLAGS FOR POTENTIAL USE IN ENVIRONMENTAL APPLICATIONS', ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, vol. 32, no. 11, pp. 2602-2610.View/Download from: Publisher's site