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: UTS OPUS or Publisher's site
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, vol. 252, pp. 1582-1592.View/Download from: Publisher's site
© 2019 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. Metal accumulation from mixtures in two Antarctic marine microalgae has the potential to cause dietary toxicity to secondary consumers in the Southern Ocean food web. Extra and intracellular partitioning shows that zinc is protective of copper toxicity at low effect concentrations.
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: UTS OPUS or 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, '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
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