Mixture Toxicity Indices in acute lethal toxicity tests

1987 ◽  
Vol 16 (1) ◽  
pp. 33-37 ◽  
Author(s):  
B. G. E. de March
Keyword(s):  
Mixture Toxicity ◽  
Toxicity Tests ◽  
Lethal Toxicity ◽  
Toxicity Indices

scholarly journals Biodegradation of a mixture of benzophenone, benzophenone-3, caffeine and carbamazepine in a laboratory test filter

2017 ◽  
Vol 82 (12) ◽  
pp. 1445-1459 ◽  
Author(s):  
Minja Bogunovic ◽  
Varja Knezevic ◽  
Jelica Simeunovic ◽  
Ivana Teodorovic ◽  
Ivana Ivancev-Tumbas
Keyword(s):  
Laboratory Test ◽  
Substantial Reduction ◽  
Mixture Toxicity ◽  
Initial Mixture ◽  
Transformation Products ◽  
Toxicity Tests ◽  
Inert Material ◽  
Residual Toxicity ◽  
Test Filter ◽  
Adsorption Processes

The biodegradation of a mixture of four pharmaceutical and personal care products (PPCPs) (benzophenone (BP), benzophenone-3 (BP-3), caffeine (CF) and carbamazepine (CBZ)) was studied in a laboratory test filter. The column was filled with inert material to exclude the adsorption processes and to enable the development of the biofilm, while river water was recirculated. High removal for BP, BP-3 and CF was observed from the beginning of the experiment at the initial concentration of 20 ?g L-1 (90?99 %). In the case of CBZ analytical difficulties were experienced. The efficacy of biodegradation reflected as a change of the overall toxicity of initial mixture of selected PPCPs vs. toxicity of samples which were undergone different biodegradation phases was assessed with two standard laboratory tests with apical endpoint ? acute toxicity test with Daphnia magna (immobilisation) and bioluminescence inhibition with Vibrio fisheri. Toxicity tests showed the substantial reduction of the overall mixture toxicity in a laboratory test filter. The residual toxicity to D. magna might be attributed to undetected transformation products.

Acute Toxicity of Binary Mixtures of Five Cations (Cu2+, Cd2+, Zn2+, Mg2+, and K+) to the Freshwater Amphipod Gammarus lacustris (Sars): Alternative Descriptive Models

1988 ◽  
Vol 45 (4) ◽  
pp. 625-633 ◽  
Author(s):  
B. G. E. de March
Keyword(s):  
Acute Toxicity ◽  
Mixture Toxicity ◽  
Probit Model ◽  
Response Surfaces ◽  
Additive Effects ◽  
Similar Action ◽  
Surface Models ◽  
Complex Linear ◽  
Different Response ◽  
Toxicity Indices

The combined results of 10 acute toxicity experiments, each testing the joint toxicity of two of the ions Cu2+, Cd2+, Zn2+, Mg2+, and K+, were examined in terms of different response surface models which could be used to make decisions about limiting toxic components in mixtures. The classical probit model for simple similar action described experimental results satisfactorily with a model R2 of 0.282; equations in which probit(p) was described directly by a linear combination of toxicant concentrations fit data significantly better, with an R2 of 0.527. Equations with more complex linear terms and appropriate weighting factors applied to the residual sums of squares yielded R2 values up to 0.931. Predicted LC50 values were midrange compared with published values. Based on the linear description of the probit response, K or Mg in combination with either of Cu, Cd, or Zn had additive effects, the combinations Cu and Cd, Cu and Zn, and Cd and Zn had more-than-additive effects, and Mg and K had less-than-additive effects. The relationships between the response surfaces, other described modes of joint action, the toxic units model, and mixture toxicity indices are discussed.

Effects of advanced oxidation processes (AOPs) on the toxicity of a mixture of pharmaceuticals

2004 ◽  
Vol 50 (5) ◽  
pp. 23-28 ◽  
Author(s):  
R. Andreozzi ◽  
L. Campanella ◽  
B. Fraysse ◽  
J. Garric ◽  
A. Gonnella ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Mixture Toxicity ◽  
Complete Removal ◽  
Toxicity Tests ◽  
Time Of Application ◽  
Synechococcus Leopoliensis ◽  
Standardized Bioassays

The possibility of applying main AOP techniques, namely ozonation, H2O2/UV photolysis and TiO2 photocatalysis to provide a significant reduction of toxicity of pharmaceutical mixtures has been evaluated. For the preparation of the mixture six pharmaceuticals were chosen among those found at highest concentrations in Sewage Treatment Plant effluents, namely carbamazepine, clofibric acid, diclofenac, sulfamethoxazole, ofloxacin and propranolol. The blue-green alga Synechococcus leopoliensis and the rotifer Brachyonus calyciflorus were utilised to assess the toxicity of the mixtures after AOP treatments. All the toxicity tests were performed using chronic standardized bioassays. The best results were obtained with ozonation. With this type of treatment a complete removal of mixture toxicity on S. leopolensis was obtained even after the shortest time of application (1 min). The ozonation treatment leads also to removal of all the pharmaceutical mixture toxicity on B. calyciflorus, by applying the oxidizing agent for at least for 2 minutes.

scholarly journals Uji Toksisitas Letal dan Subletal Logam Berat Merkuri (Hg) Terhadap Ikan Nilem (Osteochilus hasselti)

Omni-Akuatika ◽  
2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Norman Arie Prayogo ◽  
Atik Hidayati ◽  
Asrul Sahri Siregar
Keyword(s):  
Heavy Metal ◽  
Toxicity Test ◽  
Aquatic Organisms ◽  
Sublethal Effect ◽  
Aquatic Organism ◽  
Toxicity Tests ◽  
Sublethal Toxicity ◽  
Lethal Toxicity ◽  
Randomized Design ◽  
Completely Randomized Design

Mercury (Hg) is a heavy metal could pollute the river. Hg impacts on aquatic organism chronically. The influence of chemical toxic on aquatic organisms could be determined using toxicity (lethal and sublethal) tests. Osteochilus hasselti could be an object for toxicity test. A research, aiming to find LC50-96h concentration, was to find letal and subletal effects of Hg on erythrocyte and hematocryte changes. An experimental method applied Completely Randomized Design. The research was devided into 3 stages, i.e. preliminary, lethal toxicity (LC50-96h) and sublethal toxicity tests, in triplicates. Sampling of sublethal test was performed after an exposure time of 96 h (4 days) and 288 h (12 days). Lethal toxicity test data were analyzed as probit and data from sublethal toxicity test were F-tested. The result showed that LC50-96h of Hg on Osteochilus hasselti was 0.39 mg/L. The sublethal effect of Hg decreased erythrocyte ad hematocryte counts in parallel with increasing its concentration and its exposure time.Keywords: Hg, toxicity, LC50-96 hours, erythrocytes, hematocrits.

scholarly journals morse: an R-package in support of Environmental Risk Assessment

2021 ◽  
Author(s):  
Sandrine Charles ◽  
Virgile Baudrot
Keyword(s):  
Risk Assessment ◽  
Environmental Risk ◽  
Environmental Risk Assessment ◽  
Survival Data ◽  
R Package ◽  
Toxicity Tests ◽  
Model Parameters ◽  
Risk Indicator ◽  
Data Set ◽  
Toxicity Indices

Package morse is devoted to the analysis of experimental data collected from standard toxicity tests. It provides ready-to-use functions to visualize a data set and to estimate several toxicity indices to be further used in support of environmental risk assessment in full compliance with regulatory requirements. Such toxicity indices are indeed classical requested by standardized regulatory guidelines on which national agencies base their evaluation of applications for marketing authorisation of chemical active substances. Package morse can be used to get estimates of LCx (x% Lethal Concentration) or ECx (x% Effective Concentration) by fitting standard exposure-response models on toxicity test data. Risk indicator estimates as well as model parameters are provided along with the quantification of their uncertainty. Package morse can also be used to get estimates of the NEC (No Effect Concentration) by fitting a Toxicokinetic-Toxicodynamic (TKTD) model (namely GUTS models, that is General Unified Threshold models of Survival). Using GUTS models also allow to get estimates of LC(x,t) (whatever x and t) and LP(x,t), this later being defined by EFSA as the x% multiplication factor leading to an additional reduction of x% in survival at the end of the exposure profile. Above all, GUTS models can be used on data collected under time-variable exposure profiles. This paper illustrates a typical use of morse with survival data collected over time and at different increasing exposure concentrations, analysed with the reduced version of GUTS models based on the stochastic death hypothesis (namely, the GUTS-RED-SD model). This example can be followed step-by-step to analyse any new data set, as long as the data set format is respected.

Is Atyaephyra desmarestii a useful candidate for lethal and sub-lethal toxicity tests on pharmaceutical compounds?

2013 ◽  
Vol 263 ◽  
pp. 256-265 ◽  
Author(s):  
Elena Nieto ◽  
Julián Blasco ◽  
Enrique González-Ortegón ◽  
Pilar Drake ◽  
Miriam Hampel
Keyword(s):  
Pharmaceutical Compounds ◽  
Toxicity Tests ◽  
Lethal Toxicity
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