toxicant concentration
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2021 ◽  
Vol 2094 (5) ◽  
pp. 052016
Author(s):  
M Rosental ◽  
G A Sambursky

Abstract Determination of permissible concentrations of pollutants in relation to water bodies and water quality is the basis for further measures to form technological approaches to water treatment and wastewater treatment, to determine the standards of permissible exposure and technological indicators. The main standard, which is the basis for such calculations - the maximum permissible concentration (MPC) of pollutants or the approximate safe level of exposure (S), are threshold (deterministic) values. It is assumed that the establishment, for example, of the MPC for fisheries water bodies is based on the analysis of toxicological indicators. However, in fact, rationing is carried out on the basis of selective toxicological studies [1], which do not provide such determinism. The obtained data characterize only the influence of the selected levels of toxicant concentration on the studied organisms.



2021 ◽  
Author(s):  
Deng Xiru ◽  
Jiang Yingnan ◽  
Xian Qiming

Abstract The toxic effects of Lindane (γ-BHC) on Microcystis aeruginosa were studied under lab culture conditions. Total protein levels, as well as malondialdehyde (MDA) levels and superoxide dismutase (SOD) enzyme activity, in algal cells, were determined after exposure to different concentrations of Lindane. The bioaccumulation of Lindane, as well as the influence of pH and dissolved organic matter (DOM), on the toxic effects was also evaluated in algal cells. The growth of M. aeruginosa was inhibited by Lindane treatment (96 h), resulting in 50% of maximal effect (EC50) concentration of 442 μg/L. In addition the lowest observed effect concentration (LOEC) was found to be 120 μg/L, the no observed effect concentration (NOEC) 60 μg/L, and the maximum acceptable toxicant concentration (MATC) 85 μg/L. With increasing concentrations of Lindane and exposure time, M. aeruginosa growth was significantly inhibited; in addition, total protein levels and SOD activity significantly decreased. MDA concentration, however, showed an insignificant increase after 96 h. Lindane has the potential for bioaccumulation in algal cells with a bioconcentration factor (BCF) of 340. Furthermore, the toxic effects of Lindane on M. aeruginosa were influenced by environmental factors, such as pH and DOM. The toxic effects decreased with increasing pH and humic acid concentrations. Ultrastructure cell images were used to depict Lindane induced apoptosis.



2020 ◽  
Vol 29 (1) ◽  
pp. 111-121
Author(s):  
K.N.O. Bob-Manuel ◽  
A. Ugbomeh ◽  
O. Taylorharry

The effects of sub-lethal concentrations of Corexit 9500 on growth and condition factor of juveniles of Clarias gariepinus was investigated after 21days, in 2018. 160 fishes were used as test organisms with a loading of 10/treatment and were exposed to 0.00, 0.0125, 0.025 and 0.05 ml/L concentrations of Corexit 9500. Treatments were in triplicate and Complete Randomised Design was adopted. The growth in length and weight of C. gariepinus was significantly higher in the control than the test treatments (P<0.05). The increase in weight of the control was significantly different from the three treatments. Temperature was not significantly different (P>0.05); however, the DO of control was significantly higher (P < 0.05) than that of the treatments, with the lowest DO in the 0.05ml/l treatment. pH was acidic for all treatments including the control but was more acidic with increasing concentration of Corexit 9500. The pH value for each treatment was significantly different (P<0.05). The conductivity was significantly different from each other (P<0.05) with higher values at the 0.025 ml/L concentrations. The condition factor (K) decreased with increasing toxicant concentration and was significantly different (P<0.05) at 0.0125ml/L and at Weeks 2 and 3 of 0.05 ml/L. Corexit 9500 dispersants should be appropriately assessed before deployment, and their use near fish breeding grounds should be avoided. Key words: Clarias gariepinus, dispersant, growth, physicochemical parameters, sub-lethal



Author(s):  
E. A. Ivon ◽  
G. M. Ubi ◽  
N. A. Etangetuk ◽  
C. O. Anyanwu ◽  
A. N. Nkang ◽  
...  

Background: The toxic effect of Nittol detergent on the haematological parameters of the African catfish (C. gariepinus) sub-adult was investigated. The experiment was conducted in triplicates forthe four treatments. Behavioral changes in fish exposed to different concentrations of Nittol detergent ranged from erratic swimming, moribund movement, jumping and lack of balance. Similar changes were not observed in the control throughout the experiment. Nittol detergent is composed of linear alkyl benzene sulphonate (LABS), sodium tripolyphosphate (STPP), sodium carbonate, sodium sulphate, sodium per-borate and sodium silicate (perfume) as active ingredients. The fish were exposed to concentrations 1.0 g/L, 2.0 g/L, 3.0 g/L and 4.0g/L. At 1.0 g/l concentration, the mean mortality was 80% with an initial erratic swimming. Results: It was observed that mean mortality increased drastically with increasing Nittol Detergent  concentrations. At a concentration 3.0 g/L, total mortality was observed within 72 hours of exposure preceding moribund swimming while total mortality was observed at 4.0 g/L. The concentration at which 50% of the experimental fishes were killed (LC50) was 0.9 g/L. Results from statistical analysis indicated that mortality varied significantly with concentrations as higher values recorded higher mortality rates. However, mean values showed the highest mortality (74%) with Nittol detergent. Haematological results obtained from blood profile analysis showed various degrees of alterations and changes in values when compared to the control. The PCV of the exposed fish was 26% when compared to 27% in the control, HB was 8.9 (GDL) as against 9.0 Gdl of the control, total WBC was 640 x 109/L as against 1280 x 109/L of the control. The RBC reading was 4.7 compared to 5.3 (mm3) of the control. For the differential counts, the lymphocyte was 80%. Neutrophils were 4 % and monocyte 16% compared to 62%, 8% and 30% of the control respectively. The results revealed a significant decrease in PCV counts for 8.0, 16.0, 25.0, and 50.0ml/l concentration when compared to the control. There revealed significant decrease of haemoglobin count for 8.0 ml/l group (p>0.05) and significant decrease for 16.0 ml/l, 25.0 ml/l and 50.0 ml/l groups (p<0.05), when compared to the control. The results showed insignificant decrease of RBC count for 1.0 g/l (p>0.05) and a significant decrease for the 2.0, 3.0 and 4.0 g/l groups (p<0.05), compared to the control. This means that as the toxicant concentration increased, the fish red blood count decreased the more. This further implies that at higher concentration of, RBC reduces correspondingly. Lymphocytes, monocytes, and neutrophils in the control set showed (apparently normal cell after) hematoxylin and eosin staining. Differential blood samples exposed to various concentrations of Nittol Detergent showed denatured cells, haemolysis and blood cell shrinkage. Conclusion: It was therefore concluded that Nittol Detergent has significant toxic effect on the haematological parameters of C. gariepinus and recommended the control disposal of this detergent into aquatic bodies to reduce the negative impact on the blood quality of aquatic organisms.



2020 ◽  
Vol 1 (3) ◽  
pp. 21-28
Author(s):  
Iniobong R. Inyang ◽  
Dudutari E. Patani ◽  
Sylvester C. Izah

Aminoforce containing 720g/l of 2,4-dimethylamine salt induced changes on some enzymes and electrolytes in the male Oryclotagus cuniculus (New Zealand rabbit) were assayed. The organisms were exposed to varying sub-lethal concentrations of the toxicant (720g/l). The concentrations were prepared by pipetting 0.4mls, 0.8mls and 0.12mls making it up to 1.5L clean water in a metal container to make 2.0 mgl-1, 4.0 mgl-1 and 6.0 mgl-1. Aspartate amino transferase (AST), Alanine amino transferase (ALT) and Acid phosphatase (ACP) were assayed in the liver and blood. Results showed that aspartate amino transferase values in the liver and blood were significant (p<0.05) across the concentration of the toxicants. Aspartate amino transferase increased as the concentration of the toxicant increased in the liver, and decreased as the toxicant concentration increased in the blood. Alanine amino transferase in the blood and liver were akin to AST while ACP values increased in the blood and decreased in the liver as the concentration of the toxicant increased. Electrolytes (Sodium (Na+), potassium (K+) and magnesium (Mg2+) ions) showed statistical deviation across the various concentration of the toxicants. Chloride ion values stabilized in the experimental group being not significantly different (p>0.05) across the various concentration of the toxicants. From the study, AST, ALT and ACP are suitable biomarkers for showing sub-lethal effect of aminoforce on Oryclotagus cuniculus. The effects recorded clearly unveiled the potential effect of this xenobiotics on Oryclotagus cuniculus. Therefore, exposure of Oryclotagus cuniculus to this toxicant will affect the organism’s physiological responses and over prolong period of time it could lead to death. Additionally, via food chain man may be affected. The use of this toxicant close to rabbittory should be done with utmost caution.



2019 ◽  
Vol 25 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Robert Tungadi ◽  
Widysusanti Abdulkadir ◽  
Netty Ino Ischak ◽  
Bayu R Rahim

Background: Snakehead fish (Ophiocephalus striatus) is a freshwater fish that is utilized as anti-inflammatory and anticancer drug. The aim of this study was to determine the toxicity effect of snakehead fish powder (SFP), formulate it into liposome and in vitro study using sensitive and resistant breast cancer cells. Methods: Dried powder of snakehead fish was made using the atomizer then made a test solution which was divided into 7 treatment groups in different concentrations. They were exposed to zebrafish embryos then observed for 72 h post fertilization (hpf). After acquiring the half maximal inhibitory concentration (IC50) and lethal concentration (LC50) of SFP, these concentrations were used to formulate SFP into liposome by extrusion method. SFP-liposomes were characterized and stable tested. Afterwards, SFP-liposomes were evaluated in vitro using sensitive and resistant breast cancer cells. Results: The maximum allowed toxicant concentration of SFP was 0.0543 mg/mL meaning slight toxic symptoms, IC50 = 0.0945 mg/mL showing the growth inhibition of zebrafish embryos, and LC50 = 0.1549 mg/mL meaning very toxic category that has killed zebrafish embryos. The characterization results showed that size of SFP-liposome were 121 nm ± 0.29, polydispersity index 0.06 ± 0.02, zeta-potential -10.15 mV ± 0.36 and % entrapment efficiency (EE) 85.75% ± 2.24. Six weeks of stability study showed that size profile was stable at 25°C and 37°C. Moreover, SFP-liposomes inhibited breast cancer cell proliferation when evaluated with 4T1 and MDA-MB231-sensitive and resistant cells. Conclusion: SFP has bioactive compounds based on toxicity effect and can be formulated into liposome as a promising nanonutraceutical formulation.



Author(s):  
Nuria Abdrakhimovna Kanieva

The article presents the experimental data on the toxic properties of one of the main components of sewage waters of gas processing enterprises - diethanolamine. Diethanolamine is a highly toxic organic compound, its negative effect on the embryonic development of fish in the Volga-Caspian basin becomes apparent at minimal concentrations.The object of study was the developing caviar of stellate sturgeon ( Acipenser stellatus Pallas) put into diethanolamine solutions at the stage of eight blastomeres. The experiment lasts 15 days. The toxicity level and mechanism of the toxicant activity were determined by the degree of changes in morphometric parameters, behavioral reactions (general symptom complex of poisoning), physiological state and survival of organisms. It has been stated that diethanolamine causes significant changes in morphological and functional parameters of developing stellate sturgeon embryos and larvae. The greater is the toxicant concentration, the greater are the changes. There has been found the dependence of the degree of negative impact on the fish physiological state on the time of their staying in diethanolamine solutions, as well as on the stage of ontogenesis. Using the integrated approach combining toxicological, ichthyological, and physiological areas of research has revealed uneven development of embryos, decrease in their physical activity, impaired pigmentation of the integument, slowdown in growth and development, and a decrease in survival. In experimental reservoirs there was found an increase of the duration of the hatching process, as well as the growing number of individuals developing with deviations from the standard indices. The increasing concentration of the toxicant and residence time of the planting material in its solutions led to an increase in the total waste of the roe, prelarvae, and larvae of stellate sturgeon in the experimental reservoirs in comparison with the control ones.



2019 ◽  
Vol 26 (2) ◽  
pp. 397-408
Author(s):  
Olga Żuk ◽  
Grzegorz Kosior ◽  
Grzegorz Oloś

Abstract Determining the value of a half-effective or half-life concentration or dose of toxicant is the main purpose of acute toxicity studies, and this is also the most commonly used value in the toxicity characteristics of substances. By conducting tests that meet the criteria and requirements for the determination of acute toxicity, due to the use of appropriate mathematical tools and concentrations resulting in complete lethal effects in the studied groups, considerably more important values can be achieved, which give a possibility for the analysis of the entire process’s dynamics, as well as determining the threshold values of the effect time and toxicant concentration. This was the purpose of our research, in which the research species were Daphnia magna and Cypris pubera. The effect of the conducted research allowed to determine and compare the two toxicants: ammonium and copper(II) ions by it’s: concentration limit values (Cth), internal toxicity of the receptor-ligand complex (α), apparent, constant disintegration of this complex (Kapp) and different time values of the effect (Tt, Tin, MLT), which, along with concentration, is equally important determinant of the development of a toxic effect.





2019 ◽  
Vol 28 (3) ◽  
pp. 1127-1133
Author(s):  
Ghazala Ghazla ◽  
Salma Sultana ◽  
K. Al-Ghanim ◽  
Shahid Mahboob


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