EFFECTS OF USING SYNTHETIC SEA SALTS WHEN MEASURING AND MODELING COPPER TOXICITY IN SALTWATER TOXICITY TESTS

2007 ◽  
Vol 26 (5) ◽  
pp. 935 ◽  
Author(s):  
W. Ray Arnold ◽  
Jeffrey S. Cotsifas ◽  
Anna R. Winter ◽  
Joel S. Klinck ◽  
D. Scott Smith ◽  
...  
Keyword(s):  
Copper Toxicity ◽  
Toxicity Tests ◽  
Sea Salts

ASSESSMENT OF THE EFFECT OF WATER QUALITY ON COPPER TOXICITY INHYALELLA AZTECA

2015 ◽  
Vol 4 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Laura Richards ◽  
Stephanie Walsh ◽  
Carmen Shultz ◽  
Marilyne Stuart
Keyword(s):  
Ionic Strength ◽  
River Water ◽  
Sediment Toxicity ◽  
River Sediments ◽  
Copper Toxicity ◽  
Copper Tolerance ◽  
Toxicity Tests ◽  
Water Type ◽  
Ottawa River ◽  
Sediment Toxicity Tests

The objective of this study was to test the hypothesis that when standard artificial media 5-salt culture water (SAM-5S) is used to test sediment toxicity of much lower ionic-strength aquatic ecosystems, the resulting toxicity estimates are lower than if the tests had been conducted in water of comparable ionic strength. Results showed that this concern was unfounded for testing of copper toxicity to Hyalella azteca (H. azteca) in Ottawa River water. Sediment testing is often conducted using a standard water that is prepared in the laboratory. However, this water may have an ionic strength that is different than local water bodies. It follows that laboratory results using the standard water may be unrepresentative. A study was undertaken to assess the copper tolerance of 2 strains of H. azteca in SAM-5S, diluted SAM-5S (similar in electrical conductivity to Ottawa River water), and Ottawa River water. Acute (96 h) copper toxicity tests were conducted with 9–16 day-old H. azteca. For a given water type, the 2 strains of H. azteca yielded comparable responses to copper. The highest copper tolerance was found in Ottawa River water (closely followed by SAM-5S), whereas the lowest copper tolerance was found in diluted SAM-5S. Our results suggest that sediment toxicity is not lowered by the higher ionic strength of SAM-5S and that sediment toxicity tests of Ottawa River sediments, conducted with SAM-5S, can be used to estimate the in situ toxicity of the sediments.

Copper bioavailability and amelioration of toxicity in Macquarie Harbour, Tasmania, Australia

2000 ◽  
Vol 51 (1) ◽  
pp. 1 ◽  
Author(s):  
Jennifer L. Stauber ◽  
Rodney J. Benning ◽  
Leigh T. Hales ◽  
Ruth Eriksen ◽  
Barbara Nowak
Keyword(s):  
Risk Assessment ◽  
Mine Tailings ◽  
Copper Toxicity ◽  
Toxicity Tests ◽  
Copper Binding ◽  
Observable Effect ◽  
Railway Company ◽  
Complexing Capacity ◽  
Chemical Measurements ◽  
Membrane Bound

The 100-year operation of the Mount Lyell Mining and Railway Company Limited’s copper mine in Queenstown, Australia, has resulted in the deposition of over 100 million cubic metres of mine tailings, smelter slag and topsoil into the King River and Macquarie Harbour. Apreliminary risk assessment, together with chemical measurements of dissolved copper, ASV-labile copper, copper complexing capacity and resin-adsorbed copper, suggested that copper in mid-salinity harbour waters was potentially bioavailable. However, toxicity tests based on inhibition of microalgal (Nitzschia closterium) growth showed that copper in these waters was not toxic, even though labile copper concentrations (6–24 µg L−1) exceeded the concentration of lowest observable effect for algae of 5 mg L−1. Measurements of intracellular and membrane-bound copper confirmed that cell division was not affected because copper was not taken up intracellularly. Amelioration of copper toxicity was due to binding of dissolved organic matter and/or other metals at the cell membrane, preventing copper binding and uptake. An understanding of the mechanism of copper toxicity and its amelioration is vital to assessing various clean-up options for the harbour.

Use and limitations of microbial bioassays for assessing copper bioavailability in the aquatic environment

2000 ◽  
Vol 8 (4) ◽  
pp. 255-301 ◽  
Author(s):  
J L Stauber ◽  
C M Davies
Keyword(s):  
Natural Waters ◽  
Biological Effects ◽  
Measurement Techniques ◽  
Sediment Quality ◽  
Copper Toxicity ◽  
Aquatic Systems ◽  
Toxicity Tests ◽  
Test Species ◽  
Guideline Values ◽  
Copper Bioavailability

Although chemical measurement techniques and geochemical speciation modelling may detect and predict the different forms of copper in aquatic systems and hence provide some information about the likely toxicity of the water to aquatic organisms, they do not give direct quantitative data on adverse biological effects. Bioassays or toxicity tests are generic tests that use living organisms as indicators of contaminant bioavailability in aquatic systems. The microbial community, including protozoa, algae, bacteria, and fungi, provides a useful tool for directly assessing the hazard of copper in natural ecosystems. Most of our information on copper toxicity in aquatic systems comes from single-species tests using cultured organisms. However, whole community bioassays with natural phytoplankton and bacterial populations are finding increasing use. Although laboratory toxicity tests using ionic copper spiked into pristine seawater or synthetic softwater provide information on copper toxicity under controlled conditions, their usefulness for estimating bioavailable copper is limited in natural waters, where copper toxicity is ameliorated by complexation and adsorption. Careful selection of appropriately sensitive test species, bioassay endpoints, and test protocols is necessary to ensure the environmental relevance of the bioassays used. An understanding of metal speciation, metal-cell binding, mechanisms of toxicity, and limitations of the bioassays is required to understand copper bioavailability in natural waters and sediments. In this review, the use of bioassays with bacteria and microalgae for assessing copper bioavailability in marine and fresh waters and sediments is discussed, with particular emphasis on the limitations of current techniques. There is an urgent need for more environmentally relevant tests with sufficient sensitivity to detect bioavailable copper at concentrations close to water and sediment quality guideline values. Key words: bioassay, copper, metal, bioavailability, toxicity, bacteria, algae.

scholarly journals Copper Toxicity to Tropical Water Flea Daphnia carinata and Freshwater Micro-algae Scenedesmus

2020 ◽  
Vol 9 (4) ◽  
pp. 1
Author(s):  
Khoa Dinh Hoang Dang ◽  
Thi Thu Hang Pham ◽  
Ngoc Tu Anh Pham ◽  
Hien Minh Tam Le ◽  
Tran Thi Yen Nhi ◽  
...  
Keyword(s):  
Fresh Water ◽  
Anthropogenic Activities ◽  
Copper Toxicity ◽  
Chemical Characterization ◽  
Toxicity Tests ◽  
Eastern Region ◽  
Freshwater Algae ◽  
Water Flea ◽  
Freshwater Microalgae ◽  
Daphnia Carinata

Sai Gon river is one most the most important river of South-eastern region of Vietnam by providing water resources and others vital natural services for millions of people in this area. In recent years, proportion with the sharply increasing of human activities in industry and agriculture, the river is continuously loaded with xenobiotics released by anthropogenic activities. Among pollutants, heavy metals are considered as the most toxic elements to aquatic living organisms and human health. The aim of this study is to assess the sensibility of freshwater microalgae Scenedesmus and water flea Daphnia carinata, two fresh water species from Vietnam to copper (Cu). After physical and chemical characterization, field water samples from upstream Sai Gon River was used as dilution water in toxicity tests. With water flea D. carinata, the EC50 value of 48h immobilization experiment was 1.90 µg/L. Growth inhibition of the Scenedesmus algae cells was determined following exposure for 72 h, and EC50 values was 78.2 µg/L. The results showed that Cu is highly toxic to both species, and water flea D. carinata was more sensitive than freshwater algae Scenedesmus. Based on the observed high sensitivity with Cu, both D. carinata and algae Scenedesmus are potential tools for the assessment of copper pollution in fresh water of Sai Gon river.

scholarly journals The effect of field-collected biofilms on the toxicity of copper to a marine microalga (Tetraselmis sp.) in laboratory bioassays

2011 ◽  
Vol 62 (12) ◽  
pp. 1362 ◽  
Author(s):  
Jacqueline L. Levy ◽  
Jenny L. Stauber ◽  
Steven A. Wakelin ◽  
Dianne F. Jolley
Keyword(s):  
Algal Species ◽  
Copper Toxicity ◽  
Algal Growth ◽  
Toxicity Tests ◽  
Natural Systems ◽  
Marine Microalga ◽  
Ic50 Values ◽  
Test Alga ◽  
Algal Growth Rate ◽  
Laboratory Bioassays

Standard algal growth rate inhibition bioassays can lack environmental realism and may over- or underestimate metal bioavailability in natural systems. In aquatic environments, algal species interact with other biota, including other algae, bacteria and biofilms. In this work, the feasibility of incorporating marine biofilms into 72 h algal growth inhibition toxicity tests was explored. The effects of copper on Tetraselmis sp. were tested in the absence and presence of characterised field-collected biofilms. We hypothesised that the addition of biofilm would prevent copper toxicity to the alga primarily through interactions of the metal with other cells and biofilm exudates. The sensitivity of Tetraselmis sp. to copper (based on 72 h IC50 values; the copper concentration to inhibit population growth by 50%) in the presence of a blended biofilm inoculum varied 2-fold and was independent of the amount of biofilm added. However, increases in IC10 and IC20 values indicated some amelioration of copper toxicity. When intact biofilms were added to the bioassays, amelioration of toxicity was more consistent, probably due to increased binding of copper to cell surfaces or exudates. Difficulties in characterising biofilms and distinguishing that material from the test alga need to be overcome before biofilms can be routinely incorporated into laboratory bioassays.

Influence of dissolved organic matter (DOM) source on copper speciation and toxicity to Brachionus plicatilis

2016 ◽  
Vol 13 (3) ◽  
pp. 496 ◽  
Author(s):  
Tara N. Tait ◽  
Christopher A. Cooper ◽  
James C. McGeer ◽  
Chris M. Wood ◽  
D. Scott Smith
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Brachionus Plicatilis ◽  
Salt Water ◽  
Copper Toxicity ◽  
Good News ◽  
Toxicity Tests ◽  
Organic Matter Quality ◽  
Degree Of Protection ◽  
Copper Speciation

Environmental context Organic matter dissolved in water can mitigate toxic effects of copper, which should be taken into account when estimating risks of copper pollution. The composition of this organic matter, however, can vary widely, and these variations might also need to be taken into account. This work addresses the question of organic matter quality and demonstrates that only the amount and not the source influences copper toxicity – good news for risk analysis because it simplifies predictions of the effects of copper in specific receiving waters. Abstract The toxicity of copper in marine systems is dependent on its speciation and bioavailability. Dissolved organic matter (DOM) can complex copper, resulting in decreased bioavailability and hence decreased toxicity. The purpose of this study was to measure acute copper LC50 values (concentration lethal to 50% of the organisms) in natural marine waters in a sensitive organism, and identify the relationships between DOM quality and copper toxicity and speciation. Static acute copper toxicity tests (48-h LC50) were performed using the euryhaline rotifer Brachionus plicatilis. Ion-selective electrode measurements of free copper were performed at the LC50 concentrations to determine the influence of DOM source on copper speciation. LC50 values ranged from 333 to 980nM (21.1 to 62.3µgL–1) with DOC concentrations ranging from 0.55 to 7.57mgCL–1. DOC was found to be protective (R2 = 0.72, P = 0.016); however, the degree of protection decreased as DOC increased. This suggests salt-induced colloid formation could be occurring, resulting in a decrease of binding sites available to complex free copper. Free copper remained fairly constant between each sample site, with an average pCu of 10.14. Overall, this study is consistent with other studies that suggest free copper is the best species for predicting toxicity. Additionally, no significant correlation between DOM source and copper toxicity was observed as compared with total DOC concentration and copper toxicity, suggesting that DOM quality does not need to be taken into account for copper toxicity modelling in salt water.

Study of the radiomodifier effect of Pityrocarpa moniliformis extract

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
João Victor Torres de Moraes ◽  
Ricardo Luiz Calazans Luna Filho ◽  
Williams Nascimento de Siqueira ◽  
Hianna Arely Milca Fagundes Silva ◽  
Dewson Rocha Pereira ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Cellular Response ◽  
Biomphalaria Glabrata ◽  
Toxicity Tests ◽  
Antioxidant Compounds ◽  
Blastula Stage ◽  
Natural Substances ◽  
60Co Source ◽  
60Co Gamma ◽  
60Co Gamma Radiation

Ionizing radiation has been applied in several areas of knowledge, among them the study of the radiomodifier activity of natural substances. These substances can modify the cellular response to the damage induced by the radiation. Therefore, this work aimed to evaluate the radiomodifier action of Pityrocarpa moniliformis extract on Biomphalaria glabrata embryos exposed to 60Co gamma radiation. Initially, toxicity tests were performed on the extract against the B. glabrata embryos for the choice of concentration that did not cause death and embryonic malformation. Then, the antioxidant activity of the P. moniliformis extract with flavonoids and phenolic compounds was evaluated by means of the ABTS method. To evaluate the radiomodifier activity of the extract, embryos were selected in the blastula stage and irradiated with 7.5 Gy in a 60Co source (gammacell-Co60). Then, the embryos were exposed for 24 h to the extract of P. moniliformis at a concentration of 250 μg/mL. The results showed that the extract of P. moniliformis presents flavonoids and enzymatic inhibition by ABTS, which demonstrates the presence of antioxidant compounds. However, the tests of the radiomodifier activity did not present radioprotective effect for embryos exposed to ionizing radiation.

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