The Role of Acute Toxicity Tests with Aquatic Animals in Chemical Registration and Notification Schemes

1983 ◽  
Vol 15 (S1) ◽  
pp. 5-8
Author(s):  
R Lloyd
Keyword(s):  
Acute Toxicity ◽  
Aquatic Toxicity ◽  
Statistical Treatment ◽  
Significant Loss ◽  
Biological Data ◽  
Toxicity Tests ◽  
Hazard Evaluation ◽  
Mortality Data ◽  
Test Technique ◽  
Mammalian Toxicity

Existing and proposed chemical registration and notification schemes include a requirement for acute toxicity test data on representative aquatic vertebrate and invertebrate species. These data, taken in conjunction with the pattern of disposal and use of the chemical, its physical and chemical properties, its stability and its potential for biodegradation and transport in the aquatic ecosystem, together with data on mammalian toxicity, contribute towards the initial hazard evaluation. A decision is then made, inter alia, whether further aquatic toxicity tests should be requested. In order to keep such requests to a minimum, it is essential that the maximum amount of useful information should be extracted from the basic toxicity tests. There has been a recent tendency in standard fish toxicity tests to report only the 96-h LC50 together with confidence limits; the statistical treatment of mortality data has been developed to ensure the maximum accuracy of the derived LC50. Such superficial refinements tend to obscure the scope for inaccuracies in these simple biological tests. The data which are of much greater value are a time series of LC50's within the 96-h period (3, 6, 24, 48, 72 h) from which a toxicity curve can be constructed. These curves have been recognised for many years as providing valuable information on the toxicity of chemicals and form a sound foundation on which to judge the validity of the test technique used for a particular chemical, and if necessary the type of further tests required. Examples will be given of various types of curves and their possible interpretations. An essential requisite for obtaining accurate toxicity curves is that the test concentrations of a chemical must be kept as constant as possible. Because of the problems and expense of chemical analyses to check whether concentrations of a substance have remained close to the nominal value in static toxicity tests, the basic test technique should be flow-through; static tests can be used only if the existing chemical, physical and biological data indicate that there will be no significant loss of toxicant from the test solution.

PREDICTING THE AQUATIC TOXICITY OF CRUDE OILS

2001 ◽  
Vol 2001 (2) ◽  
pp. 935-940 ◽  
Author(s):  
William R. Gala ◽  
Gary A. Rausina ◽  
Michael J. Ammann ◽  
Paul Krause
Keyword(s):  
Acute Toxicity ◽  
Aquatic Toxicity ◽  
Ecological Impact ◽  
Aquatic Organisms ◽  
Standard Test ◽  
Toxicity Tests ◽  
Crude Oils ◽  
Test Species ◽  
Water Accommodated Fractions ◽  
Data Gap

ABSTRACT Aquatic toxicity information is critical to provide scientifically defensible estimates of ecological impact and natural resource injury to aquatic organisms resulting from a petroleum spill. For most crude oils, the availability of aquatic toxicity information is a significant data gap. As part of Chevron's oil-specific properties summary sheet project, a series of marine fish (silversides, top smelt) and invertebrate (mysid shrimp) acute toxicity tests on five crude oils with extensive chemical analysis (e.g., VPH C6–C9, CROSERF VOCs, EPH C10–C32, PAHs) of exposure concentrations have been performed. Acute toxicity studies were conducted under standard test guidelines. ASTM D 6081 procedures were used to prepare individual water extracts, also called water-accommodated fractions (WAFs), of each test concentration to which the test organisms were exposed. WAF preparation and testing was done in tightly closed containers with minimal headspace to reduce volatilization and maintain stable exposure levels of dissolved hydrocarbons as much as possible. Also, WAFs were replenished daily with fresh test solution. Since toxicity results are expressed as the mean exposure concentration of a particular subset of the petroleum compounds in the WAF that resulted in 50% lethality in the test species, the LC50 values in μg/L will vary depending on which subset is used to describe the effect of the oil on the aquatic organisms. Additionally, since the aquatic organisms are exposed to a mixture of hydrocarbons in the WAF, LC50 values expressed as one subset's concentration are not independent of the presence of other petroleum constituent types. The results indicate that generally invertebrates (i.e., mysid) are more sensitive than fish. LC50s expressed as total polycyclic hydrocarbons (PAHs) showed the least variability—96-hour LC50s for total PAHs ranged from 19–36 μg/L and 30–128 μg/L for mysid and fish, respectively.

scholarly journals Use of LC50 in aquatic regulatory toxicology-Disharmony in global harmonization of hazard classification of chemicals

2021 ◽  
Vol 16 (1) ◽  
pp. 91-96
Author(s):  
K.S. Pillai ◽  
K. Kobayashi ◽  
A.T. Mathai ◽  
M. Michael
Keyword(s):  
Acute Toxicity ◽  
Probit Analysis ◽  
Aquatic Toxicology ◽  
Toxicity Tests ◽  
Mortality Data ◽  
Logit Analysis ◽  
Toxicity Profile ◽  
Classification And Labeling ◽  
Hazard Classification ◽  
Wilcoxon Method

In regulatory aquatic toxicology, acute toxicity studies with chemicals are conducted with a species of fish, crustacea, and or alga. The LC50/EC50 obtained from these studies is used for the hazard classification and labeling of the chemicals. The methods like probit or logit analysis and Litchfield and Wilcoxon method are prescribed in the OECD guidelines to determine the LC50. In the present study, LC50s were calculated using probit analysis, Litchfield & Wilcoxon method, and also using the method by Trevan (the inventor of median lethal dose) using three sets of concentration-mortality data of fish acute toxicity tests. The slopes of the concentration-mortality curves, fiducial limits (95% confidence interval) of LC50s, and ‘mode’ of the concentration-mortality curves were compared. Though the methods used in the study resulted in more or less similar LC50s, the LC10 and LC90, slopes and ‘mode’ differed considerably, indicating that LC50 does not reveal the exact toxicity profile of a chemical. The LC50 calculated using Finney’s probit analysis provides better information on the toxicity profile of a chemical than the LC50calculated by Litchfield & Wilcoxon method. While interpreting LC50, the mortality occurred below 16 % (eg.,LC10) and above 84 % (eg.,LC90), slope and ‘mode’ of the concentration-mortality curve may also be considered. It is worth having a relook at the current practice of hazard classification and labeling of the chemicals based only on LC50 in regulatory aquatic toxicology.

Acute Toxicity Testing with Juvenile White Sturgeon (Acipenser transmontanus)

1998 ◽  
Vol 33 (1) ◽  
pp. 95-110 ◽  
Author(s):  
W.R. Bennett ◽  
A.P. Farrell
Keyword(s):  
Acute Toxicity ◽  
Swimming Performance ◽  
Juvenile Fish ◽  
Toxicity Testing ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Toxicity Tests ◽  
Fraser River ◽  
Acute Toxicity Tests ◽  
Acute Toxicity Testing

Abstract The primary goal of this study was to investigate the possibility of using early life stages of white sturgeon (Acipenser transmontanus) (eggs, larvae and fry) as a species relevant to the Fraser River, B.C., for the acute and sublethal toxico-logical testing of forest industry effluents. Here we report the first successful acute toxicity tests for 8-day-old larvae and 42-day-old fry exposed to several chemicals known to be released into the Fraser River (i.e., 6 monochlorovanillin [6 MVAN], 4,5 dichloroguaiacol [4,5 DCG], 4,5 dichlorocatechol [4,5 DCAT], pentachlorophenol [PCP], and didecyldimethylammonium chloride [DDAC]). In most cases, white sturgeon fry were at the lower end of the range for acute toxicity values for chlorinated phenolic compounds, when compared with other juvenile fish species, and they were extremely sensitive to DDAC. The larval stage was usually more sensitive than the fry stage. Acute toxicity tests with fertilized eggs were unsuccessful. A postexposure growth study was inconclusive because neither control nor toxicant-exposed larvae and fry withstood the additional handling used for measuring body mass. At 62-days-old, fry were more tolerant of handling. This allowed measurement of their swimming performance. Although we have concerns about the reliability of using larvae for acute toxicity testing at this time, 60-day-old white sturgeon fry would appear to be both a sensitive and relevant species for assessing environmental impacts relevant to the Fraser River.

Antiulcer and Antioxidant Activity of a Lectin from Mucuna pruriens Seeds on Ethanol- induced Gastropathy: Involvement of Alpha-2 Adrenoceptors and Prostaglandins

2019 ◽  
Vol 25 (12) ◽  
pp. 1430-1439 ◽  
Author(s):  
Isabela Ribeiro Pinto ◽  
Hellíada V. Chaves ◽  
Auriana S. Vasconcelos ◽  
Francisca Clea F de Sousa ◽  
Tatiane Santi-Gadelha ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Acute Toxicity ◽  
Antioxidant Activities ◽  
Mucuna Pruriens ◽  
Toxicity Tests ◽  
Sod Activity ◽  
Tropical Regions ◽  
Mediated Effects ◽  
Menstruation Disorders ◽  
Therapeutic Tools

Ethnopharmacological Relevance:Mucuna pruriens (Mp) belongs to Leguminosae family, it is native of tropical regions and used to treat several maladies such as urinary, neurological, and menstruation disorders, constipation, edema, fever, tuberculosis, ulcers, diabetes, arthritis, dysentery, and cardiovascular diseases. Mp seeds are rich in bioactive compounds, for instance, lectins, a heterogeneous group of proteins and glycoproteins with a potential role as therapeutic tools for several conditions, including gastric disorders. This study investigated the acute toxicity, gastroprotective, and antioxidant activities of a lectin from Mucuna pruriens seeds (MpLec) on ethanol-induced gastropathy model in mice.Materials & Methods:Mice received MpLec (5 or 10 mg/kg; i.v.) and were observed for acute toxicity signs; in another experimental series, mice were pre-treated with MpLec (0.001; 0.01 or 0.1 mg/kg, i.v.), ranitidine (80 mg/kg, p.o.), or saline (0.3 mL/30g, i.v.) before ethanol 99.9% (0.2 mL/animal, p.o.), and euthanized 30 min after ethanol challenge. Macroscopic and microscopic gastric aspects, biochemical parameters (tissue hemoglobin levels, iron-induced lipid peroxidation, GSH content, SOD activity, and gastric mucosal PGE2) were measured. Additionally, pharmacological tools (yohimbine, indomethacin, naloxone, L-NAME) were opportunely used to clarify MpLec gastroprotective mechanisms of action.Results:No toxicity signs nor death were observed at acute toxicity tests. MpLec reduced ethanol-induced gastric damage, edema, and hemorrhagic patches formation, as well as decreased lipid peroxidation, SOD activity, and increased GSH content. Yohimbine and indomethacin prevented MpLec effects, suggesting the involvement of alpha-2 adrenoceptors and prostaglandins in the MpLec-mediated effects.Conclusion:MpLec does not present toxicity signs and shows gastroprotective and antioxidant activities via alpha-2 adrenoceptors and prostaglandins in the ethanol-induced gastropathy model.

Study on the Safety of Mineral and Synthetic Oil Added Commonly Used Extreme Pressure Additives

2012 ◽  
Vol 430-432 ◽  
pp. 1386-1389
Author(s):  
Zhuo Jun Chen ◽  
Long Long Feng ◽  
Bao Liang Li ◽  
Jin Jin Yue ◽  
Ying Liang Wu ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Toxicity Test ◽  
Mineral Oil ◽  
Stimulation Test ◽  
Toxicity Tests ◽  
Acute Toxicity Test ◽  
Base Oil ◽  
Synthetic Oil ◽  
Four Levels ◽  
Oral Acute Toxicity

This article use the Sulphide Isobutene (T321), Five Sufides Dialkyl(RC2540) and Star of Phosphorus(P110) as the additives,Neopentyl Polyol Ester(NPE) and mineral oil N32 as base oil. Compound above additives and base oil for the four levels. A sample: adding 4% T321 additive in NPE. B sample: adding 4% T321 additive in N32. C sample: adding 4% RC2540 additive in NPE. D sample: adding RC2540, T321 and P110 additives in NPE (all is mass fraction). The oral acute toxicity test, eye mucous stimulation test, skin hypersensitive test, soaking tail toxicity tests were conducted in above samples. The test results show that. The mineral oil, it’s not only toxic then synthetic oil but also has a poor lubricating ability compare with the same percent additive in synthetic oil. In oral acute toxicity test, eye mucous stimulation test, skin hypersensitive test, soaking tail toxicity tests, Toxic reaction of mineral N32+4%wt Sulphide Isobutene (T321) obviously from other oil samples.

Post-treatment of sanitary landfill leachate by coagulation–flocculation using chitosan as primary coagulant

2016 ◽  
Vol 74 (1) ◽  
pp. 246-255 ◽  
Author(s):  
Inara Oliveira do Carmo Nascimento ◽  
Ana Rosa Pinto Guedes ◽  
Louisa Wessels Perelo ◽  
Luciano Matos Queiroz
Keyword(s):  
Acute Toxicity ◽  
Removal Efficiency ◽  
Landfill Leachate ◽  
Post Treatment ◽  
Toxicity Tests ◽  
Process Conditions ◽  
Sanitary Landfill ◽  
Average Growth ◽  
Acute Toxicity Tests ◽  
Sanitary Landfill Leachate

Chitosan was chosen as an alternative primary coagulant in a complementary coagulation–flocculation treatment of sanitary landfill leachate with the aim of removing recalcitrant organic matter. In order to optimize the process conditions, central composite design and response surface methodology were applied. To evaluate the performance of the process using chitosan, we also carried out tests with aluminium sulphate (Al2 (SO4)3.14 H2O) as coagulant. In addition, acute toxicity tests were carried using the duckweed Lemna minor and the guppy fish Poecilia reticulata as test organisms. The analytic hierarchy process was employed for selecting the most appropriate coagulant. Mean values of true colour removal efficiency of 80% and turbidity removal efficiency of 91.4% were reached at chitosan dosages of 960 mg L−1 at pH 8.5. The acute toxicity tests showed that organisms were sensitive to all samples, mainly after coagulation–flocculation using chitosan. CE50 for L. minor was not determined because there was no inhibition of the average growth rate and biomass production; LC50 for P. reticulata was 23% (v v−1). Multi-criteria analysis showed that alum was the most appropriate coagulant. Therefore, chitosan as primary coagulant was not considered to be a viable alternative in the post-treatment of landfill leachate.

scholarly journals Nano-sized zeolites as modulators of thiacloprid toxicity onChironomus riparius

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3525 ◽  
Author(s):  
Carla S. Lorenz ◽  
Anna-Jorina Wicht ◽  
Leyla Guluzada ◽  
Barbara Crone ◽  
Uwe Karst ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Imaging Techniques ◽  
Toxicity Tests ◽  
Biting Midge ◽  
Ms Imaging ◽  
Icp Ms ◽  
Small Primary ◽  
Acute Toxicity Tests ◽  
Investigation Period ◽  
Adsorption Rates

This study investigated whether zeolites of different size (Y30 (nano-sized) and H-Beta(OH)-III (forming large aggregates/agglomerates composed of 50 nm small primary particles)) exerted acute toxicity on larvae of the non-biting midge,Chironomus riparius, and whether such zeolites are able to modulate the toxicity of a common insecticide, thiacloprid, by means of adsorption of a dissolved toxicant. We conducted acute toxicity tests with fourth instar larvae ofC. riparius. In these tests, larvae were exposed to zeolites or thiacloprid solely, or to mixtures of both compounds. The mixtures comprised 1.0 µg/L thiacloprid in addition to low (5.2 mg/L), medium (18.2 mg/L), and high (391.7 mg/L) zeolite concentrations, resulting in different adsorption rates of thiacloprid. As biological endpoints, changes in mortality rates and in behavior were monitored every 24 h over a total investigation period of 96 h. Furthermore, we conducted chemical analyses of thiacloprid in the medium and the larvae and located the zeolite particles within the larvae by LA-ICP-MS imaging techniques. Our results demonstrate that both types of zeolites did not exert acute toxicity when applied as single-substances, but led to reduced acute toxicity of thiacloprid when applied together with thiacloprid. These results are in line with the sorption properties of zeolites indicating reduced bioavailability of thiacloprid, although our data indicate that thiacloprid can desorb from zeolites to some extent. While freely dissolved (i.e., non-sorbed) fraction of thiacloprid was a good parameter to roughly estimate toxic effects, it did not correlate with measured internal thiacloprid concentrations. Moreover, it was shown that both zeolite types were ingested by the larvae, but no indication for cellular uptake of them was found.

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