Acute/chronic ratios to estimate chronic toxicity from acute data
2
Citation
8
Reference
10
Related Paper
Citation Trend
Abstract:
Acute toxicity of 25 narcotic compounds to D. magna was determined in this paper. Acute/ Chronic Ratios (ACRs), which are often used to estimate chronic toxicity from acute toxicity data, are discussed based on Quantitative Structure‐Activity Relationships (QSARs) of the compounds between both acute and chronic toxicity data and n‐octanol/water partition coefficients, and an improved equation is derived to estimate chronic toxicity data from acute toxicity data. Application of the improved equation and ACRs is illustrated for D. magna and fathead minnow to estimate chronic toxicity from acute toxicity.Keywords:
Chronic toxicity
Daphnia magna
Recently, some natural products have been used in the fields as alternative to synthetic compounds, to minimize the negative impacts to the environment. This study aimed to verify the effects of Neem-based bio-pesticide in causing acute toxicity for a fish and chronic toxicity for a microcrustacean. To this end, Danio rerio and Daphnia magna were exposed to various concentrations of a Neem-based oil formulation. In the first experiment, adults of D. rerio were exposed for 96 hours to different concentrations to determine the median lethal concentration (LC 50-96h ). For D. magna , first an acute toxicity test was performed to determine the median effective concentration (EC 50-48h ). Based on the EC 50 established in the acute test, the concentrations for the 21-day chronic toxicity test were determined. Endpoints evaluated were reproduction (number of neonates produced) and size of D. magna . The median lethal concentration for the fish was 0.22 mL L -1 , and the median effective concentration (EC 50 - 48h ) for D. magna was 0.17 mL L -1 . In the chronic test, all concentrations affected reproduction and size of D. magna . The formulation tested may be hazardous to aquatic organisms.
Daphnia magna
Chronic toxicity
Azadirachta
Cite
Citations (7)
We addressed the individual and combined toxicity of Cu2+,Cd2+ and Se4+ to Daphnia magna with a static test method.We also employed additive index method to evaluate their combined toxicity.Individual toxicity experiment shows that the toxicity of Cu2+,Cd2+ and Se4+ is degressive.Combined toxicity experiment shows that complex toxicity effect exhibits for different concentration ratios of Cu2+,Cd2+ and Se4+.Especially,the combined toxicity effect changed from antagonistic response to synergistic response with the increase of exposure time for equal concentration ratio of Cu2+ and Cd2+.
Daphnia magna
Cite
Citations (0)
The objective of the present study was to assess the predictive capacity of the acute Cu biotic ligand model (BLM) as applied to chronic Cu toxicity to Daphnia magna in freshwaters from Chile and synthetic laboratory-prepared waters. Samples from 20 freshwater bodies were taken, chemically characterized, and used in the acute Cu BLM to predict the 21-d chronic Cu toxicity for D. magna. The half-maximal effective concentration (EC50) values, determined using the Organisation for Economic Co-operation and Development (OECD) 21-d reproduction test (OECD Method 211), were compared with the BLM simulated EC50 values. The same EC50 comparison was performed with the results of 19 chronic tests in synthetic media, with a wide range of hardness and alkalinity and a fixed 2 mg/L dissolved organic carbon (DOC) concentration. The acute BLM was modified only by adjustment of the accumulation associated with 50% of an effect value (EA50). The modified BLM model was able to predict, within a factor of two, 95% of the 21-d EC50 and 89% of the 21-d half-maximal lethal concentrations (LC50) in natural waters, and 100% of the 21-d EC50 and 21-d LC50 in synthetic waters. The regulatory implications of using a slightly modified version of an acute BLM to predict chronic effects are discussed.
Daphnia magna
EC50
Biotic Ligand Model
Alkalinity
Chronic toxicity
Copper toxicity
Cite
Citations (17)
This study aims to assess the acute and sub-chronic oral toxicity of “Tri 02” powder in experimental animals. According to World Health Organization Guidance, acute toxicity study was conducted using Swiss mice. LD50 was determined by Litchfield-Wilcoxon method, and sub-chronic toxicity of “Tri 02” at two doses (2.4 g/kg b.w/day and 7.2 g/kg b.w/day) was assessed in Wistar rats for four uninterrupted weeks. Abnormal behavior, toxic symptoms, and death were observed for 7 consecutive days to assess the effects of acute toxicity. The general behavior of the rats was observed daily, and their body weight was recorded weekly. Hematological analysis and biochemical analysis were conducted before treatment, and at 2 and 4 weeks of treatment. Macroscopic examination and histopathological examination of several organs were conducted at the end of the treatment period. The results suggested that “Tri 02” at the highest dose used for mice (187.5 g/kg b.w) did not show acute toxicity and the LD50 was determined. In terms of the sub-chonic toxicity test, after oral administration of “Tri 02” powder, hematological parameters, hepato-renal functions and microscopic images of liver and kidney at both doses were similar to the control group. In conclusion, “Tri 02” powder did not produce the acute and subchronic oral toxicity in experimental animals.
Chronic toxicity
Median lethal dose
Cite
Citations (1)
Chronic toxicity
Aquatic toxicology
Daphnia magna
Cite
Citations (9)
Daphnia magna
Thiocyanate
Cite
Citations (26)
Daphnia magna
Chronic toxicity
Soft water
Hard water
Zinc toxicity
Reproductive toxicity
Cite
Citations (76)
Acute toxicity is an important basis for the assessment of hazardous chemicals, but currently there is a huge data gap in chemical toxicity information. The in silico Quantitative Structure Activity Relationship (QSAR) models can use the existing experimental data information to predict the missing chemical toxicity information data and thus reduce animal testing. In the present study, a global QSAR model for the prediction of acute Daphnia magna toxicity has been developed based on the five principles proposed by the Organization for Economic Co-operation and Development (OECD). Moreover, a Daphnia-minnow (referring specifically to the fathead minnow) Quantitative Toxicity–Toxicity Relationship (QTTR) prediction model has been developed based on the present study and our previous work on fathead minnow (Pimephales promelas). Both the QSAR and QTTR prediction models have good goodness-of-fit, robustness, and predictive ability. Finally, the acute toxicity mode of action (MOA) for fathead minnow and Daphnia magna was compared by toxicity ratio based on interspecies toxicity data. By comparison, Daphnia magna was found more sensitive to anilines and phosphorothioates than fathead minnow. The present models can fill the acute toxicity data gap and contribute to the chemicals risk assessment and priority setting.
Daphnia magna
Pimephales promelas
Aquatic toxicology
Cite
Citations (8)