scholarly journals Evaluation of Ecotoxicity of Nanoceria to Organisms of Different Trophic Levels

2021 ◽  
Vol 108 (March) ◽  
pp. 1-5
Author(s):  
Vidhya Bharathi K.S ◽  
◽  
Djanaguiraman M ◽  
Raghu R ◽  
Jeyakumar P ◽  
...  

he present study was aimed at evaluation of the toxicity potential of nanoceria on phosphobacteria (Bacillus megaterium ; soil ecosystem), azolla (Anabaena azollae and microalgae ; Aquatic ecosystem) and sorghum (Sorghum bicolor (L.) Moench) pollen grain and photosystem (PS) II quantum yield (terrestrial ecosystem). The study examined the differences in toxicity among a different concentration of nanoceria to each organism and differences in toxicity among the organisms. In each toxicity experiment, the concentration of nanoceria used are 0, 5, 10, 25, 50, 100, 200, 400, 500, and 1000 mg L-1. The result indicated that nanoceria is not toxic to soil microbes, aquatic organisms and terrestrial plants at lower concentration (up to 25 mg L-1). However, above 25 mg L-1 concentration, differential responses between nanoceria and organisms were observed. Higher concentration (500 and 1000 mg L-1) inhibited the growth of phosphobacteria, microalgae, and pollen germination and PS II quantum yield. The adverse effect caused by nanoceria could be associated with the concentration of nanoceria, differences in interactions with the cell with nanoceria, and oxidative damage caused by nanoceria. Among the assays, pollen germination was found to be more sensitive to the nanoceria in the medium, followed by photosystem II quantum yield.

2019 ◽  
Vol 183 ◽  
pp. 109493 ◽  
Author(s):  
Rose Marie O.F. Sousa ◽  
Carla Amaral ◽  
Joana M.C. Fernandes ◽  
Irene Fraga ◽  
Sabrina Semitela ◽  
...  

1975 ◽  
Vol 189 (1096) ◽  
pp. 305-332 ◽  

A range of chlorinated hydrocarbons derived from C 1 and C 2 hydrocarbons is manufactured industrially. They are used as intermediates for further chemical manufacture and also outside the chemical industry as solvents or carriers. In the latter category losses in use are eventually dispersed to the environment. The distribution of some of these compounds, including chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene and trichloroethane, in the environment (air, water and marine sediments) has been investigated and the results are presented. The concentrations found have been compared with acute toxicity levels to fish and other aquatic organisms, ascertained by laboratory bioassay. The occurrence of the compounds has been determined in a number of marine organisms, especially those at higher trophic levels, and the accumulation of some of them has been investigated in the laboratory. Chemical and microbial degradation processes have been studied in the laboratory to help determine the course of their removal from the aqueous and aerial environment, and the half lives of some of the compounds have been estimated. It is concluded that these compounds are not persistent in the environment, and that there is no significant bioaccumulation in marine food chains.


Toxics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 261
Author(s):  
Konstantin Pikula ◽  
Mariya Tretyakova ◽  
Alexander Zakharenko ◽  
Seyed Ali Johari ◽  
Sergey Ugay ◽  
...  

Vehicle emission particles (VEPs) represent a significant part of air pollution in urban areas. However, the toxicity of this category of particles in different aquatic organisms is still unexplored. This work aimed to extend the understanding of the toxicity of the vehicle exhaust particles in two species of marine diatomic microalgae, the planktonic crustacean Artemia salina, and the sea urchin Strongylocentrotus intermedius. These aquatic species were applied for the first time in the risk assessment of VEPs. Our results demonstrated that the samples obtained from diesel-powered vehicles completely prevented egg fertilization of the sea urchin S. intermedius and caused pronounced membrane depolarization in the cells of both tested microalgae species at concentrations between 10 and 100 mg/L. The sample with the highest proportion of submicron particles and the highest content of polycyclic aromatic hydrocarbons (PAHs) had the highest growth rate inhibition in both microalgae species and caused high toxicity to the crustacean. The toxicity level of the other samples varied among the species. We can conclude that metal content and the difference in the concentrations of PAHs by itself did not directly reflect the toxic level of VEPs, but the combination of both a high number of submicron particles and high PAH concentrations had the highest toxic effect on all the tested species.


1990 ◽  
Vol 17 (5) ◽  
pp. 579 ◽  
Author(s):  
JP Krall ◽  
GE Edwards

The quantum yields of non-cyclic electron transport from photosystem II (determined from chlorophyll a fluorescence) and carbon dioxide assimilation were measured in vivo in representative species of the three subgroups of C4 plants (NADP-malic enzyme, NAD-malic enzyme and PEP-carboxykinase) over a series of intercellular CO2 concentrations (CI) at both 21% and 2% O2. The CO2 assimilation rate was independent of O2 concentration over the entire range of Ci (up to 500 μbar) in all three C4 subgroups. The quantum yield of PS II electron transport was similar, or only slightly greater, in 21% v. 2% O2 at all Ci values. In contrast, in the C3 species wheat there was a large O2 dependent increase in PS II quantum yield at low CO2, which reflects a high level of photorespiration. In the C4 plants, the relationship of the quantum yield of PS II electron transport to the quantum yield of CO2 fixation is linear suggesting that photochemical use of energy absorbed by PS II is tightly linked to CO2 fixation in C4 plants. This relationship is nearly identical in all three subgroups and may allow estimates of photosynthetic rates of C4 plants based on measurements of PS II photochemical efficiency. The results suggest that in C4 plants both the photoreduction of O2 and photorespiration are low, even at very limiting CO2 concentrations.


1999 ◽  
Vol 26 (3) ◽  
pp. 283 ◽  
Author(s):  
Congming Lu ◽  
Giuseppe Torzillo ◽  
Avigad Vonshak

The kinetic response of photosystem II (PS II) photochemistry in Spirulina platensis(Norstedt M2 ) to high salinity (0.75 M NaCl) was found to consist of two phases. The first phase, which was independent of light, was characterized by a rapid decrease (15–50%) in the maximal efficiency of PS II photochemistry (Fv /Fm), the efficiency of excitation energy capture by open PS II reaction centres (Fv′/Fm′), photochemical quenching (qp) and the quantum yield of PS II electron transport (Φ PS II) in the first 15 min, followed by a recovery up to about 80–92% of their initial levels within the next 2 h. The second phase took place after 4 h, in which further decline in above parameters occurred. Such a decline occurred only when the cells were incubated in the light, reaching levels as low as 45–70% of their initial levels after 12 h. At the same time, non-photochemical quenching (qN) and Q B -non-reducing PS II reaction centres increased significantly in the first 15 min and then recovered to the initial level during the first phase but increased again in the light in the second phase. The changes in the probability of electron transfer beyond QA (ψo) and the yield of electron transport beyond QA (φ Eo), the absorption flux (ABS/RC) and the trapping flux (TRo /RC) per PS II reaction centre also displayed two different phases. The causes responsible for the decreased quantum yield of PS II electron transport during the two phases are discussed.


2020 ◽  
Vol 31 (9) ◽  
pp. 655-675
Author(s):  
F. Lunghini ◽  
G. Marcou ◽  
P. Azam ◽  
M.H. Enrici ◽  
E. Van Miert ◽  
...  

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1126 ◽  
Author(s):  
Nemi Malhotra ◽  
Tzong-Rong Ger ◽  
Boontida Uapipatanakul ◽  
Jong-Chin Huang ◽  
Kelvin H.-C. Chen ◽  
...  

This review summarizes the present knowledge on the toxicity of copper and copper nanoparticles (CuNPs) to various fish species. In previous decades, the excessive usage of metal and metallic nanoparticles has increased significantly, increasing the probability of the accumulation and discharge of metals in various trophic levels of the environment. Due to these concerns, it is important to understand the toxicity mechanisms of metals and metallic nanoparticles before they lead to unhealthy effects on human health. In this review paper, we specifically focus on the effect of metal copper and CuNPs on different fish organs under different physiochemical parameters of various water bodies. Nowadays, different forms of copper have distinctive and specific usages, e.g., copper sulfate is a well-established pesticide which is used to control the growth of algae in lakes and ponds. Deactivating the fungi enzymes prevents fungal spores from germinating. This process of deactivation is achieved via the free cupric ions, which are established as the most toxic forms of copper. Complexes of copper with other ligands may or may not be bioavailable for use in aquatic organisms. On the other hand, CuNPs have shown cost-effectiveness and numerous promising uses, but the toxicity and availability of copper in a nanoparticle form is largely unknown, Additionally, physiochemical factors such as the hardness of the water, alkalinity, presence of inorganic and organic ligands, levels of pH, and temperature in various different water bodies affect the toxicity caused by copper and CuNPs. However, comprehensive knowledge and data regarding the pattern of toxicity for copper metal ions and CuNPs in marine organisms is still limited. In this review, we carry out a critical analysis of the availability of the toxicological profiles of copper metal ions and CuNPs for different fishes in order to understand the toxicity mechanisms of copper and CuNPs. We believe that this review will provide valuable information on the toxicological profile of copper, which will further help in devising safe guidelines for the usage of copper and CuNPs in a sustainable manner.


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