Acute toxicity and bioaccumulation of arsenic in freshwater clam Corbicula fluminea

Arsenic is a potent human carcinogen of skin, lung, and urinary bladder. Freshwater clam Corbicula fluminea is a commercially important native species in Taiwan. C. fluminea is also a suitable biomonitoring test organism. Little is known, however, about the actual effects of arsenic on C. fluminea. The objectives of this study were to provide information on the acute toxicity and bioaccumulation kinetics of arsenic in C. fluminea. We carried out a 14-day exposure experiment to obtain bioaccumulation parameters. Uptake was very rapid when C. fluminea was first exposed and then slightly decayed during the uptake phase of the experiment and an uptake rate constant of 1.718 +/- 6.70 (mean +/- SE) mL g(-1) d(-1) was estimated. The elimination of arsenic from C. fluminea obeyed first-order depuration kinetics (r(2) = 0.85, p < 0.05) with a calculated half-life of 6.80 days. The derived bioaccumulation factor of 16.84 suggests that arsenic has a high potential for bioaccumulation in C. fluminea. This had important implications for dietary exposure of arsenic to humans who eat contaminated clams, because the soft tissue usually constitutes the majority of tissue consumed. The 96-h LC50 value was estimated to be 20.74 (95% CI: 11.74-30.79) mg L(-1) obtained from a 7-day acute toxicity bioassay. We also kinetically linked an acute toxicity model and a Hill sigmoid model to reconstruct an internal effect concentration based dose-response profile to assess the effect of soft tissue arsenic burden on the C. fluminea mortality. This result could be used to support the establishment of an ecological risk assessment to prevent possible ecosystem and human health consequences.     

A dose-based modeling approach for accumulation and toxicity of arsenic in tilapia Oreochromis mossambicus

We proposed an approach to relate metal toxicity to the concentrations of arsenic (As) in specific target organs of tilapia Oreochromis mossambicus. The relationships among As exposure, uptake, accumulation, and toxicity of tilapia were investigated using kinetic and dynamic modeling. The biouptake rate of waterborne As through the gills of fish was dependent on exposure concentrations, in that the relationship was well described by incorporating Michaelis-Menten type uptake kinetics. The fitted bioaffinity parameter and limiting uptake flux were 3.07 +/- 2.21 microg/mL(-1) (mean +/- SD) and 2.17 +/- 0.38 microg/mL(-1)/d(-1), respectively, suggesting that a low As binding affinity of tilapia gills, yet a relatively high binding capacity was obtained. The toxicity of As was analyzed by determining the lethal exposure concentration associated with a mortality of 50% (LC50) at different integration times. Our results demonstrate that 96-h and incipient LC50s for tilapia are 28.68 (95% CI: 15.98-47.38) and 25.55 microg/mL(-1), respectively. The organ-specific internal residue associated with 50% mortality was estimated by combining the model-predicted toxicokinetic parameters and the area-under-curve (AUC)-based time-integrated concentration toxicity model. A physiologically based toxicokinetic model was constructed to elucidate the principle mechanisms that account for the observed data and to predict the kinetics of As in tilapia under different water exposure scenarios. We employed the Hill equation model to predict the organ-specific dose-response relationships. We used the liver as a surrogate of target sites to assess the As toxicity to tilapia because of its higher sensitivity to As toxic effects. The predicted mortalities never reach 50% when the tilapia were exposed to waterborne As <2 microg/mL(-1). The predicted mortality is, however, slightly higher than the observed values before the 10th day in that the profile reached the 70% maximum mortality, which is comparable to the observed data when the tilapia were exposed to 4 microg/mL(-1). Our results show that a dose-based toxicokinetic and toxicodynamic modeling approach successfully links metal exposure to bioavailability, bioaccumulation, and toxicity, under variable exposure scenarios.     

Acute toxicity and bioaccumulation of pesticide Diazinon in red tilapia (Oreochromis niloticus x Mossambicus albina)

Young red tilapias were exposed for 96 h to each one of 6 concentrations of the pesticide Diazinon in order to determine the pesticide's acute toxicity level. After the ascertaining the lethal concentration (LC50) at 96 h, a level 10 times lower was selected for the bioaccumulation study of the pesticide in male and female specimens exposed for 9 days. The elimination process was carried out for 10 days beginning right after the conclusion of the accumulation process. Analytical procedures were developed and used for the studies of acute toxicity and bioaccumulation of Diazinon in red tilapia. A lethal concentration [LC50 (96 h)] of 3.85 mg/L was found, and steady-state accumulation, at a concentration of 28.45 mg/kg, was reached at 7.72 days. In the elimination process a concentration of 0.29 mg/kg was found in tilapia tissue by the sixth day after the fish were moved to clean water, and it continued to decrease quickly toward nondetectable levels.     

Bioenergetics-based matrix population modeling enhances life-cycle toxicity assessment of tilapia Oreochromis mossambicus exposed to arsenic

The objective of this study was to integrate a bioenergetics-based modeling approach into a population stage structure to enhance life-cycle toxicity assessments of the effects of waterborne arsenic (As) on the population dynamics of the tilapia Oreochromis mossambicus. The proposed mathematical model links a Leslie matrix population model and a universal ontogenetic growth model embedding the population-level growth rate and stage-specific modes of toxic action. We present data analyses of key parameters and distributions and discuss the processes of data capture and analysis and the impact of acute/chronic As toxicity responses on population-level effects. We employed a three-parameter Hill equation model to describe the relationship between tilapia whole-body burden and mortality in order to estimate the probability of stage-specific vital rate of survival. Using the DEBtox theory, we distinguished three modes of toxic action (MOA): direct effects on growth and indirect effects via maintenance and food consumption on inhibition by arsenic of the growth of a tilapia population. The asymptotic population growth rate decreased from lambda = 1.0027 for the control group to lambda = 0.9935 for tilapia population exposed to 4 microg mL(-1) As, indicating a potential risk of population intrinsic growth rates for tilapia exposed to higher levels of waterborne As. Our results estimated that an As concentration of 1.02 microg mL(-1) would cause a 50% reduction in the tilapia population. We found that the interplay between external stressors of waterborne As concentration and internally generated modes of action decreasing feeding in the juvenile stage and increasing the maintenance cost in the adult stage had a pronounced influence on the population stage structure of tilapia.     

Acute toxicity of intratracheal arsenic trioxide instillation in rat lungs

This study investigated the acute toxicity of different concentrations of arsenic trioxide (As₂O₃; ATO) on rat lungs. In total, 160 Wistar rats were randomly divided into the control, low‐, medium‐ and high‐dose groups, which were exposed to 0, 0.16, 1.60 and 16 μg/kg of ATO by intratracheal instillation, respectively. Samples were collected at 6, 12, 24, 48 and 72 hours after exposure and the dynamic changes indicative of acute lung toxicity were monitored. Compared with the control group, the exposure groups exhibited significant changes such as increased lung water content ratio and protein concentration in the bronchoalveolar lavage fluid, pulmonary interstitial thickening, cell membrane edema, increased inflammatory factor concentration, JNK and P38 were significantly activated, and the degree of phosphorylation was increased. Furthermore, all the changes in the exposure groups were exposure concentration‐dependent. ATO respiratory tract exposure can cause restrictive ventilatory disturbance in rats, and the degree of injury is exposure concentration‐dependent.     

Arsenic exposure, urinary arsenic speciation, and peripheral vascular disease in blackfoot disease-hyperendemic villages in Taiwan

Long-term exposure to ingested inorganic arsenic is associated with peripheral vascular disease (PVD) in the blackfoot disease (BFD)-hyperendemic area in Taiwan. This study further examined the interaction between arsenic exposure and urinary arsenic speciation on the risk of PVD. A total of 479 (220 men and 259 women) adults residing in the BFD-hyperendemic area were studied. Doppler ultrasound was used to diagnose PVD. Arsenic exposure was estimated by an index of cumulative arsenic exposure (CAE). Urinary levels of total arsenic, inorganic arsenite (As(III)) and arsenate (As(V)), monomethylarsonic acid (MMA(V)), and dimethylarsinic acid (DMA(V)) were determined. Primary methylation index [PMI = MMA(V)/(As(III) + As(V))] and secondary methylation index (SMI = DMA(V)/MMA(V)) were calculated. The association between PVD and urinary arsenic parameters was evaluated with consideration of the interaction with CAE and the confounding effects of age, sex, body mass index, total cholesterol, triglycerides, cigarette smoking, and alcohol consumption. Results showed that aging was associated with a diminishing capacity to methylate inorganic arsenic and women possessed a more efficient arsenic methylation capacity than men did. PVD risk increased with a higher CAE and a lower capacity to methylate arsenic to DMA(V). The multivariate-adjusted odds ratios for CAE of 0, 0.1-15.4, and >15.4 mg/L x year were 1.00, 3.41 (0.74-15.78), and 4.62 (0.96-22.21), respectively (P < 0.05, trend test); and for PMI < or = 1.77 and SMI > 6.93, PMI > 1.77 and SMI > 6.93, PMI > 1.77 and SMI < or = 6.93, and PMI < or = 1.77 and SMI < or = 6.93 were 1.00, 2.93 (0.90-9.52), 2.85 (1.05-7.73), and 3.60 (1.12-11.56), respectively (P < 0.05, trend test). It was concluded that individuals with a higher arsenic exposure and a lower capacity to methylate inorganic arsenic to DMA(V) have a higher risk of developing PVD in the BFD-hyperendemic area in Taiwan.     

Chronic toxicity and bioaccumulation of mercuric chloride in the fathead minnow (Pimephales promelas)

Fathead minnows (Pimephales promelas) were exposed to various concentrations of mercuric chloride in water to determine its acute and chronic (including reproduction) toxicity and to measure bioaccimulalion. Mean LC₅₀ values of HgCl₂ for juvenile fatheads were 168, 112, 84, and 74 μg Hg/l at 4, 5, 6, and 7 days, respectively. Following 41 wk of exposure to 0.26 to 3.69 μg/l, females were significantly smaller than controls at all concentrations except 0.50 μg/l and males showed reduced growth at 3.69 μg/l. Over half of the fish at 2.01 and 3.69 μg/l were severely stunted and scoliosis was prevalent among these stunted fish. No spawning occurred at and above 1.02 μg/l and the number of spawning pairs was reduced at 0.26 and 0.50 μg/l resulting in total egg production of 46 and 54%, respectively, of control. Thirty-day growth of second-generation larvae (from transferred control embryos at and above 1.02 μg/l) was significantly reduced at all mercury concentrations tested. No effects on hatchability or larval survival were detected. Chronically-exposed fish accumulated mean whole body total mercury residues of 1.36 to 18,80 μg/g of tissue (wet weight) from 0.26 to 3.69 μg/l, respectively. Uptake appeared proportional to water concentration; bioconcentration factors varied between 4380 and 5680.The influence of diet on mercury toxicity and bioaccumulation was studied during two 60-day larval fathead exposures. Overall recuccd growth and possibly enhanced toxic effects occurred in larvae on the dry trout starter diet compared to larvae fed on Artemia. Mercury uptake appeared influenced by the severity of toxic effects.     

Acute toxicity, behavioral changes, and histopathological effects of deltamethrin on tissues (gills, liver, brain, spleen, kidney, muscle, skin) of Nile tilapia (Oreochromis niloticus L.) fingerlings

Deltamethrin, a synthetic pyrethroid contaminating aquatic ecosystems as a potential toxic pollutant, was investigated in the present study for acute toxicity. The purpose of this study was to evaluate LC(50) values of deltamethrin on Nile tilapia (Oreochromis niloticus L.) fingerlings and investigate histopathological responses of fish exposed to deltamethrin. The 48 h LC(50) value for Nile tilapia fingerlings was estimated as 4.85 microg/L using static test system. In addition, behavioral changes at each deltamethrin concentration were observed closely. All fish, exposed to 5 microg/L deltamethrin revealed severe morphological alterations in the gills and liver. In the gills hyperemia, fusion of secondary lamellae and telangiectasis were observed; whereas hydropic degenerations in liver were observed in all examined fish. The results are significant for reporting acute deltamethrin toxicity in terms of behavioral and histopathological changes: Deltamethrin is highly toxic to fingerlings.     

Toxicological effects and bioaccumulation in the freshwater clam (Corbicula fluminea) following exposure to trivalent arsenic

Contamination of aquatic environments by arsenic is a serious worldwide problem. The main objective of this work was to evaluate the response of a freshwater clam (Corbicula fluminea) to arsenic (As III) exposure and infer its potential as a biological indicator of contamination. Metallothioneins (MTs) were used as indicators of metalloid toxicity in combination with an histological and histochemical evaluation. After a period of acclimatization in the laboratory, 50 C. fluminea (0.4 g +/- 0.1) were exposed to different nominal concentrations of arsenic (100, 300, 500, and 1000 microg L(-1)) for 7 days. The concentration of total As III in the water and in the tissues of the organisms was determined by atomic absorption spectrometry, and MTs were quantified through differential pulse polarography. Results suggest that the organisms exposed to the concentrations of 300 and 1000 microg As L(-1) accumulated the highest levels of As III in the tissues (17 +/- 9 and 15 +/- 3 microg g(-1) distilled water, respectively), which was confirmed through histochemical analysis. An apparent induction of MTs was also observed in the organisms exposed to As III, suggesting that C. fluminea possesses some capacity for arsenic regulation. The results suggest that the induction of MTs may be of high interest as a biomarker for arsenic contamination in aquatic environments, and confirms the potential of C. fluminea as a biological indicator.     

Intersex tilapia (Oreochromis spp.) from a contaminated river in Taiwan: A case study

River pollution in Taiwan is rather serious, but so far there have been no reports of fish intersex problems. This report reveals that 50% male tilapia in the Era-Jiin River of southern Taiwan were found to be feminized in an October 8, 1994 collection from station EJ-2 of this river. After discounting all other possible causative factors, and correlating with endocrine disrupting chemicals found in this river, we suggest that there is a great possibility that the occurrence of intersex tilapia was caused by these chemicals. The above finding suggests that greater attention needs to be given to endocrine disrupting chemicals problems.     

Acute toxicity and bioaccumulation of aqueous and sediment-bound metals in the estuarine amphipod Melita plumulosa

The sensitivities of juvenile and adult amphipods to metals (Cd, Cu, Ni, Pb, and Zn) in whole sediment and water-only exposures were compared using a newly developed acute test with the estuarine species Melita plumulosa. Endpoints included survival and bioaccumulation in adults, and survival and growth (body length) in juveniles over 96 h water-only and 10 day sediment exposures. Juveniles were more sensitive than adults to metals, either bound to sediments or in the aqueous phase. Although LOEC values for copper and zinc in juvenile whole-sediment tests (820 and 2290 mg/kg dry weight, respectively) were high in comparison with interim sediment quality guideline values for individual metals (270 and 410 for copper and zinc respectively), they were generally within the range of concentrations found in contaminated sediments in local estuaries. Accumulation of metals, together with the low porewater metal concentrations in whole-sediment tests, indicated that the ingestion of sediment is an important source of zinc and copper and cause of toxicity in this species.     

Effect of silver nanoparticle surface coating on bioaccumulation and reproductive toxicity in earthworms (Eisenia fetida)

Abstract

The purpose of this study was to investigate the effect of surface coating on the toxicity of silver nanoparticles (Ag NPs) soil. Earthworms (Eisenia fetida) were exposed to AgNO₃ and Ag NPs with similar size ranges coated with either polyvinylpyrrolidone (hydrophilic) or oleic acid (amphiphilic) during a standard sub-chronic reproduction toxicity test. No significant effects on growth or mortality were observed within any of the test treatments. Significant decreases in reproduction were seen in earthworms exposed to AgNO3, (94.21 mg kg^-1) as well as earthworms exposed to Ag NPs with either coating (727.6 mg kg^-1 for oleic acid and 773.3 mg kg^-1 for polyvinylpyrrolidone). The concentrations of Ag NPs at which effects were observed are much higher than predicted concentrations of Ag NPs in sewage sludge amended soils; however, the concentrations at which adverse effects of AgNO₃ were observed are similar to the highest concentrations of Ag presently observed in sewage sludge in the United States. Earthworms accumulated Ag in a concentration-dependent manner from all Ag sources, with more Ag accumulating in tissues from AgNO₃ compared to earthorms exposed to equivalent concentrations of Ag NPs. No differences were observed in Ag accumulation or toxicity between earthworms exposed to Ag NPs with polyvinylpyrrolidone or oleic acid coatings.     

Arsenic species contents at aquaculture farm and in farmed mouthbreeder (Oreochromis mossambicus) in blackfoot disease hyperendemic areas.

A study was conducted to measure the arsenic species in farmed mouthbreeder (Oreochromis mossambicus) and culture ponds in water in blackfoot disease (BFD) hyperendemic areas in Taiwan. The relationships between arsenic species of aquaculture ponds and farmed fish were also explored. Biota samples were extracted with methanol/water (1/1, v/v) using a Soxhlet extraction apparatus. The concentrations of arsenite As (III), arsenate As (V), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) of extracts were measured by high-performance liquid chromatography (HPLC) linked to a hydride generator and atomic absorption spectrometry (HG-AAS). Moreover, arsenobetaine (AB) was analyzed by HPLC linked to ultra violet (UV) and HG-AAS. Concentrations of arsenic species were determined in 68 mouthbreeder (O. mossambicus) samples and 21 culture ponds from Putai and Yichu Townships of Chiayi County and Hsuehchia and Peimen Townships of Tainan County. The mean arsenic levels of culture ponds in Putai, Yichu, Hsuehchia, and Peimen were 75.8, 15.1, 14.4, and 221.0 microg/l, respectively. The water of culture ponds was dominated by As (V). The inorganic arsenic percentage of fish (7.4%) was higher than that reported by other seafood surveys. Except for the MMA and As (III) levels, As (V), DMA, AB, and total arsenic levels in fish significantly increased with inorganic and total arsenic concentrations of the pond water. Inorganic arsenic species are more toxic than methyl arsenic species. Therefore the effect of inorganic arsenic species might result in a greater number of adverse health effects to the general public. It is of importance to evaluate the inorganic arsenic levels of farmed seafood in arsenic-contaminated areas.     

The toxicity and bioaccumulation of cadmium and copper as affected by humic acid

The toxicity of Cd and Cu to daphnids was evaluated over a 42-day exposure period at three humic acid concentrations. The addition of humic acid to test water decreased the acute and chronic toxicity of Cu but increased the acute and chronic toxicity of Cd. However, there was no effect of HA on the bioaccumulation of either metal. At the highest concentration, the presence of humic acid actually resulted in an increase in mean brood sizes of Cu-exposed animals and prevented a reduction in mean brood sizes of Cd-exposed animals.     

Developmental toxicity assessment of arsenic acid in mice and rabbits

To evaluate potential effects of exposure to inorganic arsenic throughout major organogenesis, CD-1 mice and New Zealand White rabbits were gavaged with arsenic acid dosages of 0, 7.5, 24, or 48 mg/kg/d on gestation days (GD) 6 through 15 (mice) or 0, 0.19, 0.75, or 3.0 mg/kg/d on GD 6 through 18 (rabbits) and examined at sacrifice (GD 18, mice; GD 29, rabbits) for evidence of toxicity. Two high-dose mice died, and survivors at the high and intermediate doses had decreased weight gains. High-dose-group fetal weights were decreased; no significant decreases in fetal weight or increases in prenatal mortality were seen at other dosages. Similar incidences of malformations occurred in all groups of mice, including controls. At the high dose in rabbits, seven does died or became moribund, and prenatal mortality was increased; surviving does had signs of toxicity, including decreased body weight. Does given lower doses appeared unaffected. Fetal weights were unaffected by treatment, and there were no effects at other doses. These data revealed an absence of dose-related effects in both species at arsenic exposures that were not maternally toxic. In mice, 7.5 mg/kg/d was the maternal No-Observed-Adverse-Effect-Level (NOAEL); the developmental toxicity NOAEL, while less well defined, was judged to be 7.5 mg/kg/d. In rabbits, 0.75 mg/kg/d was the NOAEL for both maternal and developmental toxicity.     

薏苡仁多糖急性毒性及遗传毒性试验研究

目的了解薏苡仁多糖的毒理学安全性。方法小鼠急性毒性试验和遗传毒性试验（Ames试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验）。结果薏苡仁多糖的小鼠经口LD50〉20g·kg^-1;在Ames试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验中均呈阴性反应,未显示有遗传毒性作用。结论薏苡仁多糖基本无毒性。     

Time‐dependent protective efficacy of Trolox (vitamin E analog) against microcystin‐induced toxicity in tilapia (Oreochromis niloticus)

Microcystins (MCs), hepatotoxins from cyanobacteria, induce oxidative stress and pathological changes in fish that can be ameliorated with chemoprotectants such as vitamin E (vit E). This study investigated the time period after MCs exposure in which Trolox, a vitamin E analog, is effective against oxidative and histological damage in different organs of tilapia (Oreochromis niloticus). Fish were fed Trolox supplement (700 mg/kg diet) for 7 days, or received only commercial fish food, and then were exposed to a single oral dose of 120 μg/fish microcystin‐LR, and sacrificed in 24, 48, or 72 h. The Trolox protective efficacy was evaluated based on lipid peroxidation (LPO), protein oxidation, enzymatic and non‐enzymatic antioxidants, and a morphologic study. Regarding the oxidative stress biomarkers altered by MCs, the higher protective action of Trolox was observed 24 h post toxin exposure, although it extends also until 48 h in gills (superoxide dismutase (SOD), catalase (CAT)), and liver, where glutathione reductase (GR) backed to control values 48 and 72 h after the toxin application. Glutathione‐S‐ transferase (GST) activity in the liver was ameliorated by the chemoprotectant after 24 and 48 h, although control values were not recovered. Trolox modulation of these biomarkers and its ability to quench free radicals explain the recovery of LPO values in all organs at 24 h and also in gills at 48 h. Histopathologically, Trolox efficacy was more evident after 72 h. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.     

Acute intoxication of deltamethrin in monosex Nile tilapia, Oreochromis niloticus with special reference to the clinical, biochemical and haematological effects

Deltamethrin, a synthetic pyrethroid pesticide, potential toxic pollutant and significant direct risk to the aquatic ecosystems, was investigated in the present study for its toxic impact on adult monosex Nile tilapia on the basis of acute static bioassay test, and comparison of clinical, biochemical and haemato logical examinations with deltamethrin-free control group. The 96 hLC₅₀ value of deltamethrin for monosex tilapia was 14.6 μg/L. The abnormal behavioral responses and toxic symptoms were described. Fish exposed to the higher deltamethrin concentration (15 μg/L) for 96 h showed significantly higher lymphocytes, total leucocytic and erythrocytic counts, haemoglobin percentage and packed cell volume content and significantly lower neutrophils compared to the control group. Deltamethrin caused adverse effects in the form of hypoproteinemia, hypoalbuminemia, hypercholesterolemia, hypoglycemia and significant increase of serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities. The results provide evidence that deltamethrin pollution may have adverse impacts and was highly toxic to monosex tilapia.     

Effects of depuration on histopathological changes in tilapia (Oreochromis niloticus) after exposure to cylindrospermopsin

Cylindrospermopsin (CYN) is a highly water‐soluble cytotoxin produced by several species of freshwater cyanobacteria and it is considered the second most studied cyanotoxin worldwide. CYN acts as a potent protein and glutathione synthesis inhibitor, as well as inducing genotoxicity, oxidative stress and histopathological alterations. Studies concerning the depuration of cyanobacterial toxins in aquatic organisms, especially in fish, are of great interest for fish economy and public health, but are scarce in the case of CYN. This is the first study reporting the ability of depuration (3 ? 7 days) in reversing or ameliorating the histopathological lesions induced in liver, kidney, heart, intestines, and gills of tilapia (Oreochromis niloticus ) due to exposure by immersion to repeated doses of a CYN‐containing culture of A. ovalisporum for 14 days. The main histopathological changes induced by CYN were glucogenic degeneration and loss of the normal hepatic cord‐structure (liver), hyperemia, dilated Bowman's capsule and cellular tumefaction (kidney), myofibrolysis, hemorrhages and edema (heart), necrosis and partial loss of microvilli (gastrointestinal tract), and hyperemia and inflammatory cells infiltrates (gills). After 3 days of depuration, gills were totally recovered, while the liver, kidney, and gastrointestinal tract required 7 days, and longer depuration periods may be needed for a full recovery of the heart. In addition, the morphometric study indicated that depuration managed to reverse the affectation in the hepatocytes nuclear diameters and cross sections of the proximal and distal convoluted tubules induced in CYN‐exposed fish. In general, these results validate depuration as an effective practice for detoxification of fish contaminated with CYN. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1318–1332, 2017.     

Acute and subacute (28-Day) toxicity studies of ionic liquid,didecyldimethyl ammonium acesulfamate,in rats

The aim of this study was to investigate acute and subacute oral toxicity of an ionic liquid, didecyldimethylammonium acesulfamate [DDA][Ace], in rats. The compound tested was classified to the fourth toxicity class with a fixed LD₅₀ cut-off value of 500?mg/kg. Organ pathology induced by [DDA][Ace] in acute experiments included exfoliation of the surface layer of the digestive tract and alveolar septa in lung parenchyma. In a subacute experiment, rats were administered 10, 50, and 100?mg/kg/day [DDA][Ace] for 28 days. Reduced body weight gain and reduced food consumption was observed in mid- and high-dose rats. Statistically significant hematology changes were found mostly in high-dose groups of both sexes: increases in hematocrit, mean corpuscular volume, and mean platelet volume. Statistically significant changes in clinical chemistry parameters included increases in the GGT, SDH, and LDH activity and bilirubin concentration, and decreases in triglycerides, glucose, and inorganic phosphorus concentration. No treatment-related microscopic changes were observed. Under the conditions of this study, the lowest-observed-adverse-effect level of [DDA][Ace] was considered to be 10?mg/kg/day.