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Martin Grosell - One of the best experts on this subject based on the ideXlab platform.
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effects of water chemistry on the chronic toxicity of lead to the cladoceran Ceriodaphnia dubia
Ecotoxicology and Environmental Safety, 2011Co-Authors: Edward M Mager, Kevin V. Brix, Adam C Ryan, Robert M Gerdes, Martin GrosellAbstract:As the first step toward parameterization of a chronic lead (Pb) biotic ligand model (BLM) for Ceriodaphnia dubia, 7-d toxicity tests were performed in waters modified to evaluate the influences of hardness, DOM (as Suwannee River NOM and Aldrich humic acid (HA)), pH (buffered with 4 mM MOPS) and alkalinity on the chronic toxicity of Pb. Calculated EC20s for the control base water test and each of the most extreme modified test waters were as follows in m gL � 1 Pb (95% confidence interval): base water control¼ 45 (14–53), 5 mM CaSO4 ¼22 (12–30), 32 mg L � 1 DOM ¼ 523 (388–573), 2.5 mM NaHCO3¼73 (21–120) and pH 6.4 buffered with MOPS¼ 3.9 m gL � 1 Pb (1–5). Results indicate that hardness does not protect against chronic toxicity of Pb to C. dubia, whereas HA does protect at the highest concentration tested (597 mM). Additionally, our findings suggest that low pH increases the chronic toxicity of Pb whereas increased alkalinity is protective. The findings reported herein support the need for a chronic Pb BLM as an alternative approach to hardness-based regulations.
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influences of water chemistry on the acute toxicity of lead to pimephales promelas and Ceriodaphnia dubia
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2011Co-Authors: Edward M Mager, Kevin V. Brix, Andrew J Esbaugh, Adam C Ryan, Martin GrosellAbstract:article The acute toxicity of lead (Pb) was examined for fathead minnows (Pimephales promelas; 96-h) and daphnids (Ceriodaphnia dubia; 48-h) in waters modified for hardness (as CaSO4), dissolved organic carbon (DOC; as Aldrich humic acid) and alkalinity (as NaHCO3) for parameterization of an acute freshwater biotic ligand model (BLM). Additionally, acute (96-h) and chronic (30-d) bioassays were performed for P. promelas to more clearly define the influence of pH (5.5-8.3) on Pb toxicity as modified by addition of HCl or NaOH using an automated titration system. Results indicate that Ca 2+
Marianne V. Moore - One of the best experts on this subject based on the ideXlab platform.
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a four day survival and reproduction toxicity test for Ceriodaphnia dubia
Environmental Toxicology and Chemistry, 1991Co-Authors: James T. Oris, Robert W. Winner, Marianne V. MooreAbstract:A 4-d survival and reproduction toxicity test utilizing Ceriodaphnia dubia has been developed and evaluated. This toxicity test has been compared to the standard 7-d test using a total of 12 toxicants encompassing a wide range of chemical classes. In addition, 48-h LC50 values were determined for each chemical in the absence of food. Four-day and seven-day tests were run concurrently, twice for each chemical. Less-than-12-h-old neonates for both 4-d and 7-d tests were segregated into individual test cups on Fridays. Animals for 7-d tests were immediately exposed to the test chemical. Animals for 4-d tests were held in control water and not exposed to the test chemical until day 3. Animals were fed daily and solutions were changed on Mondays and Wednesdays. Chemical concentrations were measured by appropriate analytical techniques during each test. Survival and mean total young per female were used to compare the relative sensitivity of the 4-d and 7-d tests. Data were analyzed using traditional hypothesis testing techniques to determine chronic values from the no-observed- and lowest-observed-effect concentrations. In addition, data were analyzed using a nonparametric, monotonic smoothing technique to determine interpolated point estimates and 95% confidence intervals for the 50% inhibition concentration (IC50). Comparisons between the 4-d test versus the 7-d test for both methods of data analysis indicated that the 4-d test provides an acceptable level of sensitivity in the toxicity testing of single compounds.
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A four‐day survival and reproduction toxicity test for Ceriodaphnia dubia
Environmental Toxicology and Chemistry, 1991Co-Authors: James T. Oris, Robert W. Winner, Marianne V. MooreAbstract:A 4-d survival and reproduction toxicity test utilizing Ceriodaphnia dubia has been developed and evaluated. This toxicity test has been compared to the standard 7-d test using a total of 12 toxicants encompassing a wide range of chemical classes. In addition, 48-h LC50 values were determined for each chemical in the absence of food. Four-day and seven-day tests were run concurrently, twice for each chemical. Less-than-12-h-old neonates for both 4-d and 7-d tests were segregated into individual test cups on Fridays. Animals for 7-d tests were immediately exposed to the test chemical. Animals for 4-d tests were held in control water and not exposed to the test chemical until day 3. Animals were fed daily and solutions were changed on Mondays and Wednesdays. Chemical concentrations were measured by appropriate analytical techniques during each test. Survival and mean total young per female were used to compare the relative sensitivity of the 4-d and 7-d tests. Data were analyzed using traditional hypothesis testing techniques to determine chronic values from the no-observed- and lowest-observed-effect concentrations. In addition, data were analyzed using a nonparametric, monotonic smoothing technique to determine interpolated point estimates and 95% confidence intervals for the 50% inhibition concentration (IC50). Comparisons between the 4-d test versus the 7-d test for both methods of data analysis indicated that the 4-d test provides an acceptable level of sensitivity in the toxicity testing of single compounds.
Robert W. Winner - One of the best experts on this subject based on the ideXlab platform.
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a four day survival and reproduction toxicity test for Ceriodaphnia dubia
Environmental Toxicology and Chemistry, 1991Co-Authors: James T. Oris, Robert W. Winner, Marianne V. MooreAbstract:A 4-d survival and reproduction toxicity test utilizing Ceriodaphnia dubia has been developed and evaluated. This toxicity test has been compared to the standard 7-d test using a total of 12 toxicants encompassing a wide range of chemical classes. In addition, 48-h LC50 values were determined for each chemical in the absence of food. Four-day and seven-day tests were run concurrently, twice for each chemical. Less-than-12-h-old neonates for both 4-d and 7-d tests were segregated into individual test cups on Fridays. Animals for 7-d tests were immediately exposed to the test chemical. Animals for 4-d tests were held in control water and not exposed to the test chemical until day 3. Animals were fed daily and solutions were changed on Mondays and Wednesdays. Chemical concentrations were measured by appropriate analytical techniques during each test. Survival and mean total young per female were used to compare the relative sensitivity of the 4-d and 7-d tests. Data were analyzed using traditional hypothesis testing techniques to determine chronic values from the no-observed- and lowest-observed-effect concentrations. In addition, data were analyzed using a nonparametric, monotonic smoothing technique to determine interpolated point estimates and 95% confidence intervals for the 50% inhibition concentration (IC50). Comparisons between the 4-d test versus the 7-d test for both methods of data analysis indicated that the 4-d test provides an acceptable level of sensitivity in the toxicity testing of single compounds.
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Toxicity of copper to Chlamydomonas reinhardtii (Chlorophyceae) and Ceriodaphnia dubia (Crustacea) in relation to changes in water chemistry of a freshwater pond
Aquatic Toxicology, 1991Co-Authors: Robert W. Winner, Heather A. OwenAbstract:Abstract Chlamydomonas reinhardtii and Ceriodaphnia dubia were used to evaluate effects of seasonal changes in the water chemistry (DOC, alkalinity, hardness) of a freshwater pond on the toxicity of copper. Chlamydomonas was much more sensitive to copper than was Ceriodaphia . The only correlation between copper toxicity and water chemistry was a positive correlation between DOC concentrations and algal density after a 72-h exposure to copper. Because freshwater DOC changes qualitatively as well as quantitatively over time, it is postulated that these qualitative changes result in unpredictable differences in copper-binding affinity of the DOC which makes it impossible to use DOC concentrations to predict environmentally safe concentrations of copper.
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A four‐day survival and reproduction toxicity test for Ceriodaphnia dubia
Environmental Toxicology and Chemistry, 1991Co-Authors: James T. Oris, Robert W. Winner, Marianne V. MooreAbstract:A 4-d survival and reproduction toxicity test utilizing Ceriodaphnia dubia has been developed and evaluated. This toxicity test has been compared to the standard 7-d test using a total of 12 toxicants encompassing a wide range of chemical classes. In addition, 48-h LC50 values were determined for each chemical in the absence of food. Four-day and seven-day tests were run concurrently, twice for each chemical. Less-than-12-h-old neonates for both 4-d and 7-d tests were segregated into individual test cups on Fridays. Animals for 7-d tests were immediately exposed to the test chemical. Animals for 4-d tests were held in control water and not exposed to the test chemical until day 3. Animals were fed daily and solutions were changed on Mondays and Wednesdays. Chemical concentrations were measured by appropriate analytical techniques during each test. Survival and mean total young per female were used to compare the relative sensitivity of the 4-d and 7-d tests. Data were analyzed using traditional hypothesis testing techniques to determine chronic values from the no-observed- and lowest-observed-effect concentrations. In addition, data were analyzed using a nonparametric, monotonic smoothing technique to determine interpolated point estimates and 95% confidence intervals for the 50% inhibition concentration (IC50). Comparisons between the 4-d test versus the 7-d test for both methods of data analysis indicated that the 4-d test provides an acceptable level of sensitivity in the toxicity testing of single compounds.
Kevin V. Brix - One of the best experts on this subject based on the ideXlab platform.
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effects of water chemistry on the chronic toxicity of lead to the cladoceran Ceriodaphnia dubia
Ecotoxicology and Environmental Safety, 2011Co-Authors: Edward M Mager, Kevin V. Brix, Adam C Ryan, Robert M Gerdes, Martin GrosellAbstract:As the first step toward parameterization of a chronic lead (Pb) biotic ligand model (BLM) for Ceriodaphnia dubia, 7-d toxicity tests were performed in waters modified to evaluate the influences of hardness, DOM (as Suwannee River NOM and Aldrich humic acid (HA)), pH (buffered with 4 mM MOPS) and alkalinity on the chronic toxicity of Pb. Calculated EC20s for the control base water test and each of the most extreme modified test waters were as follows in m gL � 1 Pb (95% confidence interval): base water control¼ 45 (14–53), 5 mM CaSO4 ¼22 (12–30), 32 mg L � 1 DOM ¼ 523 (388–573), 2.5 mM NaHCO3¼73 (21–120) and pH 6.4 buffered with MOPS¼ 3.9 m gL � 1 Pb (1–5). Results indicate that hardness does not protect against chronic toxicity of Pb to C. dubia, whereas HA does protect at the highest concentration tested (597 mM). Additionally, our findings suggest that low pH increases the chronic toxicity of Pb whereas increased alkalinity is protective. The findings reported herein support the need for a chronic Pb BLM as an alternative approach to hardness-based regulations.
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influences of water chemistry on the acute toxicity of lead to pimephales promelas and Ceriodaphnia dubia
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2011Co-Authors: Edward M Mager, Kevin V. Brix, Andrew J Esbaugh, Adam C Ryan, Martin GrosellAbstract:article The acute toxicity of lead (Pb) was examined for fathead minnows (Pimephales promelas; 96-h) and daphnids (Ceriodaphnia dubia; 48-h) in waters modified for hardness (as CaSO4), dissolved organic carbon (DOC; as Aldrich humic acid) and alkalinity (as NaHCO3) for parameterization of an acute freshwater biotic ligand model (BLM). Additionally, acute (96-h) and chronic (30-d) bioassays were performed for P. promelas to more clearly define the influence of pH (5.5-8.3) on Pb toxicity as modified by addition of HCl or NaOH using an automated titration system. Results indicate that Ca 2+
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Acute and chronic toxicity of nickel to a cladoceran (Ceriodaphnia dubia) and an amphipod (Hyalella azteca).
Environmental Toxicology and Chemistry, 2004Co-Authors: James Keithly, John A. Brooker, David K. Deforest, Benjamin K. Wu, Kevin V. BrixAbstract:This study evaluated acute and chronic nickel (Ni) toxicity to Ceriodaphnia dubia and Hyalella azteca with the objective of generating information for the development of a biotic ligand model for Ni. Testing with C. dubia was used to evaluate the effect of ambient hardness on Ni toxicity, whereas the larger H. azteca was used to derive lethal body burden information for Ni toxicity. As was expected, acute C. dubia median lethal concentrations (LC50s) for Ni increased with increasing water hardness. The 48-hLC50s were 81, 148, 261, and 400 μg/L at hardnesses of 50, 113, 161, and 253 mg/L (as CaCO3), respectively. Ceriodaphnia dubia was found to be significantly more sensitive in chronic exposures than other species tested (including other daphnids such as Daphnia magna); chronic toxicity was less dependent on hardness than was acute toxicity. Chronic 20% effective concentrations (EC20s) were estimated at
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acute and chronic toxicity of nickel to a cladoceran Ceriodaphnia dubia and an amphipod hyalella azteca
Environmental Toxicology and Chemistry, 2004Co-Authors: James Keithly, John A. Brooker, David K. Deforest, Benjamin K. Wu, Kevin V. BrixAbstract:This study evaluated acute and chronic nickel (Ni) toxicity to Ceriodaphnia dubia and Hyalella azteca with the objective of generating information for the development of a biotic ligand model for Ni. Testing with C. dubia was used to evaluate the effect of ambient hardness on Ni toxicity, whereas the larger H. azteca was used to derive lethal body burden information for Ni toxicity. As was expected, acute C. dubia median lethal concentrations (LC50s) for Ni increased with increasing water hardness. The 48-hLC50s were 81, 148, 261, and 400 μg/L at hardnesses of 50, 113, 161, and 253 mg/L (as CaCO3), respectively. Ceriodaphnia dubia was found to be significantly more sensitive in chronic exposures than other species tested (including other daphnids such as Daphnia magna); chronic toxicity was less dependent on hardness than was acute toxicity. Chronic 20% effective concentrations (EC20s) were estimated at <3.8, 4.7, 4.0, and 6.9 μg/L at hardnesses of 50, 113, 161, and 253 mg/L, respectively. Testing with H. azteca resulted in a 96-h LC50 of 3,045 μg/L and a 14-d EC20 of 61 μg/L at a hardness of 98 mg/L (as CaCO3). Survival was more sensitive than was growth in the chronic study with H. azteca. The 20% lethal accumulation effect level based on measured Ni body burdens was 247 nmol/g wet weight.
Jianmin Wang - One of the best experts on this subject based on the ideXlab platform.
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Algae (Raphidocelis subcapitata) mitigate combined toxicity of microplastic and lead on Ceriodaphnia dubia
Frontiers of Environmental Science & Engineering, 2020Co-Authors: Xuesong Liu, Jianmin WangAbstract:They not only directly impact aquatic organisms, but also indirectly impact these organisms by interacting with background toxins in the environment. Moreover, under realistic environmental conditions, algae, a natural food for aquatic organisms, may alter the toxicity pattern related to MPs. In this research, we first examined the toxicity of MPs alone, and their effect on the toxicity of lead (Pb) on Ceriodaphnia dubia (C. dubia), a model aquatic organism for toxicity survey. Then, we investigated the effect of algae on the combined toxicity of MPs and Pb. We observed that, MPs significantly increased Pb toxicity, which was related to the increase in soluble Pb concentration and the intake of Pb-loaded MPs, both of which increased the accumulation of Pb in C. dubia. The presence of algae mitigated the combined toxicity of MPs and Pb, although algae alone increased Pb accumulation. Therefore, the toxicity mitigation through algae uptake came from mechanisms other than Pb accumulation, which will need further investigation.
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Toxicity of lead on Ceriodaphnia dubia in the presence of nano-CeO2 and nano-TiO2
Chemosphere, 2012Co-Authors: Demin Wang, Jiangtao Wang, Jianmin WangAbstract:Abstract Although engineered nanoparticles (NPs) could negatively impact environmental organisms, the synergistic effect of NPs and other toxic substances, which could be more significant than that of NP alone, have seldom been examined. The effect of two common NPs, nano-CeO2 and nano-TiO2, on the toxicity of Pb was evaluated using Ceriodaphnia dubia (C. dubia) as the model organism. Standard EPA procedures were followed in the toxicity evaluation. The toxicity of bare NPs (without Pb) was first evaluated and safe doses (levels without causing lethal effect) of NPs were used in the synergistic studies. It was found that the overall toxicity of Pb in the system containing NPs was greater than that of Pb alone, as indicted by the reduced median lethal concentration (LC50) of soluble Pb. The sorption of Pb onto the NP, and the uptake of NPs in the gastrointestinal tract of C. dubia were validated. Therefore, the uptake of Pb-loaded NPs increased the exposure of C. dubia to Pb, resulting in the enhanced toxicity. Reducing the solution pH could shift Pb speciation and enhance the overall toxicity of Pb, with or without the presence of NPs.
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bioaccumulation of fe2o3 magnetic nanoparticles in Ceriodaphnia dubia
Environmental Pollution, 2012Co-Authors: Ji Hu, Jiangtao Wang, Demin Wang, Jianmin WangAbstract:Abstract While nano-Fe 2 O 3 (magnetic) is generally considered non-toxic, it could serve as a carrier of other toxic chemicals such as As(V) and enhance their toxicity. The bioaccumulation of nano-Fe 2 O 3 (m) with different exposure times, NP concentrations, and pH conditions was investigated using Ceriodaphnia dubia ( C. dubia ) as the model organism. Under natural pH conditions, C. dubia significantly accumulated nano-Fe 2 O 3 (m) in the gut, with the maximum accumulation being achieved after 6 h of exposure. The concentration of nano-Fe 2 O 3 also impacted its accumulation, with the maximum uptake occurring at 20 mg/L or more. In addition, the highest bioaccumulation occurred in a pH range of 7–8 where the highest feeding rate was reported, confirming that the ingestion of NPs is the main route of nano-Fe 2 O 3 (m) bioaccumulation. In a clean environment without NPs, depuration of nano-Fe 2 O 3 (m) occurred, and food addition accelerated the depuration process.
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synergistic toxic effect of nano tio2 and as v on Ceriodaphnia dubia
Science of The Total Environment, 2011Co-Authors: Demin Wang, Ji Hu, Jianmin Wang, David R IronsAbstract:Abstract Due to the active development and application of nanotechnology, engineered nanomaterials (ENMs) are becoming a new class of environmental pollutants that may significantly impact the environment and human health. While many toxicity investigations have been conducted, there is little information about the synergistic effect of ENMs and other toxic compounds in the environment. In order to extend this knowledge, the combined effect of TiO2 nanoparticles (n-TiO2) and As(V) were investigated. High concentrations of As(V) can accumulate on the n-TiO2 surface. Cultured Ceriodaphnia dubia (C. dubia) species were used to examine the synergistic toxic effect through exposure to 1) n-TiO2 suspensions, 2) As(V) solutions, and 3) mixtures of n-TiO2 and As(V) suspensions. Results showed that n-TiO2 alone was not toxic when the concentration was less than 400 mg/L and that the 24-hour median lethal concentration (LC50) of As(V) alone was 3.68 ± 0.22 mg/L. However, in the presence of low concentrations of n-TiO2, the toxicity of As(V) increased significantly. At the same initial As(V) concentration, the toxicity of n-TiO2 first increased, reached a maximum, and then decreased with an increase in n-TiO2 concentration. Hydrodynamic size and sorption capacity were most important parameters for toxicity.