scholarly journals Effects of Exposure to Semiconductor Nanoparticles on Aquatic Organisms

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kenton Leigh ◽  
Jennifer Bouldin ◽  
Roger Buchanan
Keyword(s):  
Quantum Dots ◽  
Surface Waters ◽  
Aquatic Organisms ◽  
Consumer Products ◽  
Aquatic Systems ◽  
Great Promise ◽  
Aquatic Environments ◽  
Potential Toxicity ◽  
Optical And Mechanical Properties ◽  
Many Sources

Because of their unique physical, optical, and mechanical properties, nanomaterials hold great promise in improving on a wide variety of current technologies. Consequently, their use in research and consumer products is increasing rapidly, and contamination of the environment with various nanomaterials seems inevitable. Because surface waters receive pollutants and contaminants from many sources including nanoparticles and act as reservoirs and conduits for many environmental contaminants, understanding the potential impacts of nanoparticles on the organisms within these environments is critical to evaluating their potential toxicity. While there is much to be learned about interactions between nanomaterials and aquatic systems, there have been a number of recent reports of interactions of quantum dots (QDs) with aquatic environments and aquatic organisms. This review is focused on providing a summary of recent work investigating the impacts of quantum dots on aquatic organisms.

scholarly journals Effects of chlorination, ultraviolet and ozone disinfection on the biotoxicity of triclosan

2018 ◽  
Vol 19 (4) ◽  
pp. 1175-1180
Author(s):  
Lei Chen ◽  
Zhipeng Wang
Keyword(s):  
Water Treatment ◽  
Surface Waters ◽  
Risk Evaluation ◽  
Aquatic Organisms ◽  
Human Beings ◽  
Potential Toxicity ◽  
Treatment Processes ◽  
Drinking Waters ◽  
Before And After ◽  
Ozone Disinfection

Abstract The contamination of triclosan, which is a widely used antimicrobial agent, is of emerging concern for its potential toxicity to aquatic organisms and human beings. Chlorination, UV254 irradiation and ozonation are the main disinfection methods used in water treatment processes. Although studies have shown that triclosan could react with free chlorine and ozone, and undergo photolysis under UV irradiation, few of them focused on the effects of disinfection processes on the biotoxicity of triclosan. In the present study, the potential risk of triclosan in water before and after laboratory-scale disinfection processes, including chlorination, UV254 irradiation and ozonation, was evaluated by bioassay. The results showed that both acute toxicity and genetic toxicity of triclosan was increased by chlorination and UV254 disinfection but decreased by ozone disinfection. In other words, ozonation would be a preferential disinfection method for triclosan-containing surface waters. This finding will help us to choose an appropriate disinfection method for water treatment. Furthermore, it is proved that bioassay could be a feasible way for risk evaluation when concentrations of antibiotics in surface waters or drinking waters are very low.

scholarly journals A Brief Review of the Structure, Cytotoxicity, Synthesis, and Biodegradation of Microcystins

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2147
Author(s):  
Anjali Krishnan ◽  
Xiaozhen Mou
Keyword(s):  
Health Hazard ◽  
Aquatic Organisms ◽  
Water Soluble ◽  
Cyanobacterial Blooms ◽  
Aquatic Environments ◽  
Natural Environments ◽  
Exposure Pathway ◽  
Environmental Transformation ◽  
Cyclic Heptapeptide ◽  
Harmful Cyanobacterial Blooms

Harmful cyanobacterial blooms pose an environmental health hazard due to the release of water-soluble cyanotoxins. One of the most prevalent cyanotoxins in nature is microcystins (MCs), a class of cyclic heptapeptide hepatotoxins, and they are produced by several common cyanobacteria in aquatic environments. Once released from cyanobacterial cells, MCs are subjected to physical chemical and biological transformations in natural environments. MCs can also be taken up and accumulated in aquatic organisms and their grazers/predators and induce toxic effects in several organisms, including humans. This brief review aimed to summarize our current understanding on the chemical structure, exposure pathway, cytotoxicity, biosynthesis, and environmental transformation of microcystins.

scholarly journals The Role of Sodium in Stabilizing Tin-Lead (Sn-Pb) Alloyed Perovskite Quantum Dots

2021 ◽  
Author(s):  
Junke Jiang ◽  
Feng Liu ◽  
Qing Shen ◽  
Shuxia Tao
Keyword(s):  
Quantum Dots ◽  
Phase Stability ◽  
Band Gaps ◽  
Great Promise ◽  
Narrow Bandgap ◽  
Perovskite Quantum Dots ◽  
Optoelectronic Applications

Narrow-bandgap CsSnxPb1-xI3 perovskite quantum dots (QDs) show great promise for optoelectronic applications owing to their reduced use of toxic Pb, improved phase stability, and tunable band gaps in the visible...

scholarly journals Solvent regulation synthesis of single-component white emission carbon quantum dots for white light-emitting diodes

2021 ◽  
Vol 10 (1) ◽  
pp. 465-477
Author(s):  
Longshi Rao ◽  
Qing Zhang ◽  
Mingfu Wen ◽  
Zhongfa Mao ◽  
Huaxian Wei ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diodes ◽  
Carbon Quantum Dots ◽  
Single Component ◽  
Great Promise ◽  
Solvent Engineering ◽  
Light Emitting ◽  
White Emission ◽  
White Light Emitting Diodes

Abstract White light-emitting diodes (WLEDs) hold great promise in lighting, display, and visible light communication devices, and single-component white emission carbon quantum dots (SCWE-CQDs) as the key component of WLEDs have many outstanding advantages. However, rapid and efficient synthesis of SCWE-CQDs with high photoluminescence quantum yield (PLQY) and stability remains challenging. Here, we report a novel solvent engineering strategy to obtain highly photoluminescent SCWE-CQDs by controlling the dilution ratios between N,N-dimethylformamide (DMF) and pristine red carbon quantum dots (RCQDs) solution. By optimizing synthesis conditions, the relative PLQY of the SCWE-CQDs solution reached 53%. Morphological, structural, and optical property characterizations indicate that the combined action of the hydrogen bond (HB) effect and the size effect leads to the blue shift of RCQDs, but the HB effect is more dominant than the particle size in causing large spectral shifts. In addition, the WLEDs with high color rendering index of 89 and remarkable reliability were obtained based on the highly photoluminescent SCWE-CQDs. This facile solvent engineering approach for synthesizing tunable emission CQDs will promote the progress of carbon-based luminescent materials for applications in optoelectronic devices.

Using sediment cores to establish targets for the remediation of aquatic environments

2015 ◽  
Vol 73 (3) ◽  
pp. 628-635 ◽  
Author(s):  
Anna Lintern ◽  
Marion Anderson ◽  
Paul Leahy ◽  
Ana Deletic ◽  
David McCarthy
Keyword(s):  
Sediment Cores ◽  
Sediment Quality ◽  
Aquatic Systems ◽  
Quality Data ◽  
Aquatic Environments ◽  
Site Specific ◽  
European Settlement ◽  
Quality Guidelines ◽  
Water And Sediment ◽  
Water And Sediment Quality

When assigning site-specific restoration targets for deteriorating aquatic systems, it is necessary to have an understanding of the undisturbed or background state of the system. However, the site-specific characteristics of aquatic systems prior to disturbance are mostly unknown, due to the lack of historical water and sediment quality data. This study aims to introduce a method for filling this gap in our understanding, using dated sediment cores from the beds of aquatic environments. We used Bolin Billabong, a floodplain lake of the Yarra River (South-East Australia), as a case study to demonstrate the application of this method. We identified the concentrations of aluminium, cadmium, chromium, copper, iron, lead, manganese, nickel, tin and zinc at 8 cm intervals through the sediment core. This showed that aluminium, chromium, copper, iron, lead, nickel, tin and zinc concentrations in Bolin Billabong sediments significantly increased after European settlement in the river catchment in the mid-19th century. The differences between current Australian sediment quality guidelines trigger values and the background metal concentrations in Bolin Billabong sediments underscore the value of using locally relevant background toxicant concentrations when setting water and sediment quality targets.

scholarly journals A Review on Fish Sensory Systems and Amazon Water Types With Implications to Biodiversity

2021 ◽  
Vol 8 ◽  
Author(s):  
Elio de Almeida Borghezan ◽  
Tiago Henrique da Silva Pires ◽  
Takehide Ikeda ◽  
Jansen Zuanon ◽  
Shiro Kohshima
Keyword(s):  
Aquatic Organisms ◽  
Sensory Systems ◽  
Spatial Distance ◽  
Fish Diversity ◽  
Aquatic Environments ◽  
Water Types ◽  
Local Adaptations ◽  
Freshwater Organisms ◽  
Research Perspectives ◽  
Lighting Environment

The Amazon has the highest richness of freshwater organisms in the world, which has led to a multitude of hypotheses on the mechanisms that generated this biodiversity. However, most of these hypotheses focus on the spatial distance of populations, a framework that fails to provide an explicit mechanism of speciation. Ecological conditions in Amazon freshwaters can be strikingly distinct, as it has been recognized since Alfred Russel Wallace’s categorization into black, white, and blue (= clear) waters. Water types reflect differences in turbidity, dissolved organic matter, electrical conductivity, pH, amount of nutrients and lighting environment, characteristics that directly affect the sensory abilities of aquatic organisms. Since natural selection drives evolution of sensory systems to function optimally according to environmental conditions, the sensory systems of Amazon freshwater organisms are expected to vary according to their environment. When differences in sensory systems affect chances of interbreeding between populations, local adaptations may result in speciation. Here, we briefly present the limnologic characteristics of Amazonian water types and how they are expected to influence photo-, chemical-, mechano-, and electro-reception of aquatic organisms, focusing on fish. We put forward that the effect of different water types on the adaptation of sensory systems is an important mechanism that contributed to the evolution of fish diversity. We point toward underexplored research perspectives on how divergent selection may act on sensory systems and thus contribute to the origin and maintenance of the biodiversity of Amazon aquatic environments.

scholarly journals Risk Assessment of Malakite with the Active Substances Dithianon and Pyrimenthanil

2019 ◽  
pp. 312-314
Author(s):  
Torsten Källqvist ◽  
Merete Grung ◽  
Katrine Borgå ◽  
Hubert Dirven ◽  
Ole Martin Eklo ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Surface Waters ◽  
Plant Protection ◽  
Aquatic Organisms ◽  
Toxicity Tests ◽  
Concentration Addition ◽  
Active Ingredients ◽  
Active Substances ◽  
Assessment Factor

The plant protection product Malakite (BAS 669 01 F), containing the active substances dithianon and pyrimethanil, is a fungicide against scab in pome fruits. Products containing these active plant protection substances are approved in Norway, but not with both substances in the same product. The Swedish Chemicals Agency (KemI) has as zonal Rapporteur Member State (zRMS) of the Northern Zone evaluated the product Malakite and decided on non-approval due to the observation of unacceptable effects in exposed birds, aquatic organisms, non-target arthropods and earthworms. On request from The Norwegian Food Safety Authority, the VKM Panel on Plant Protection Products has discussed the available data and the report prepared by KemI, and has concluded as follows on the questions raised: On the refinement of DT50 in long term risk assessment for birds: It is the view of the VKM panel that the refinement is not acceptable because the analysis using first order kinetics seems not in line with a realistic and sufficiently conservative approach for the data provided. Furthermore, field studies from more sites are required. On the long term cumulative effects of the active substances on birds: VKM shares the view of KemI, that the combined sub-lethal and reproduction effects should be assessed because the mode of action of the two ingredients has only been shown in fungi, and since the mechanisms in birds could be different. On the reduction of assessment factor for fish: VKM opposes to the reduction of assessment factor for dithianon in fish because the data from acute toxicity tests cannot be extrapolated to chronic toxicity, and because the factor should reflect not only the variation in interspecies sensitivity, but also the uncertainty involved in extrapolation from laboratory tests to the field situation. On the choice of end point in risk assessment for fish: The VKM panel considers the NOEC of dithianon for fish determined from the study at pH 7.9 not to be adequate for the more acidic Norwegian surface waters, and recommends using the data from the test performed at pH 6.5. On the formulation studies for aquatic organisms: It is the opinion of the VKM panel that the formulation studies may be used together with corresponding studies with the active ingredients as long as the studies compared are performed and evaluated according to the same principles. However, VKM notes that the formulation tests as well as the tests of the active ingredients have been performed at high pH values, which are not representative to most Norwegian surface waters. Thus, the toxic effect of dithianon shown in these tests are likely to be lower than expected under typical conditions in Norway. On the assessment factors for concentration addition in fish: It is the opinion of the VKM panel that a reduction in assessment factor for one component in a mixture cannot be used for a formulation containing components for which a similar reduction has not been accepted. On effect studies of active substances and formulations on non-target arthropods: The VKM panel shares the view of KemI that the risk assessment should be based on all available information, including the studies presented for the active substances. On the endpoint in earthworm risk assessment: VKM supports the view of KemI that the observed effects of pyrimethanil on reproduction of earthworms should be considered in the risk assessment of Malakite.

scholarly journals Development of Daphnia magna under exposure to the xenobiotic octylphenol

2014 ◽  
Vol 6 (2) ◽  
pp. 155-158
Author(s):  
Thanh Son Dao ◽  
Thi My Chi Vo ◽  
Hong Lan Chi Do ◽  
Phuoc Dan Nguyen
Keyword(s):  
Developing Country ◽  
Daphnia Magna ◽  
Aquatic Organisms ◽  
Environmental Concerns ◽  
Human Beings ◽  
Ecological Health ◽  
Potential Toxicity ◽  
Chronic Effects ◽  
High Concentrations ◽  
Significant Mortality

Xenobiotics are of human and environmental concerns due to their potential toxicity. Octylphenol is one of the very common and daily used xenobiotics in door and out door activities of human beings. Toxicity of octylphenol to aquatic organisms, especially to zooplankton (e.g. Daphnia magna) was investigated but not fully understood. In this study we evaluated the chronic effects of octylphenol at the concentrations of 5, 50 and 500 µg L-1 on Daphnia magna over a period of 14 days. The results showed that low concentration of octylphenol (5 µg L-1) stimulated the maturation while high concentrations of the chemical (50 and 500 µg L-1) caused a significant mortality to the Daphnia. Besides, all the tested concentrations of octylphenol had serious impacts on fecundity and growth of the animals. Investigations on the presence, distribution, fate and toxicity of xonobiotics including octylphenol in the developing country environment are suggested for human, environmental and ecological health protection. Những hợp chất tổng hợp đang là mối quan ngại cho con người và môi trường vì khả năng gây độc của chúng. Octylphenol là một trong những hợp chất tổng hợp được sử dụng phổ biến và thường xuyên trong những hoạt động của con người trong nhà và ngoài trời. Độc tính của octylphenol đối với thủy sinh vật, đặc biệt đối với động vật phù du (vd. Daphnia magna) mặc dù đã được nghiên cứu nhưng vẫn chưa được hiểu biết đầy đủ. Trong nghiên cứu này, chúng tôi đánh giá ảnh hưởng mãn tính của octylphenol ở các nồng độ 5, 50 và 500 µg/lít lên Daphnia magna trong thời gian 14 ngày. Kết quả cho thấy ở nồng độ octylphenol thấp (5 µg/lít) kích thích sự thành thục của sinh vật trong khi ở nồng độ cao hơn (50 và 500 µg/lít) gây chết đáng kể Daphnia. Bên cạnh đó, tất cả các nồng độ ocytlphenol dùng trong thí nghiệm gây ảnh hưởng nghiêm trọng lên sức sinh sản và sinh trưởng của sinh vật. Nghiên cứu về sự hiện diện, phân bố, phát tán và độc tính của những chất tổng hợp bao gồm octylphenol ở các nước đang phát triển nên được tiến hành vì mục tiêu bảo vệ sức khỏe con người, môi trường và hệ sinh thái.

scholarly journals Effects of Humic Acid and Natural Sunlight Irradiation on the Behaviour of Zinc Oxide Nanoparticles in the Aqueous Environment

2020 ◽  
Vol 11 (4) ◽  
pp. 11256-11271
Keyword(s):  
Humic Acid ◽  
Zno Nanoparticles ◽  
Zinc Oxide Nanoparticles ◽  
Large Scale ◽  
Aquatic Organisms ◽  
Consumer Products ◽  
Oxide Nanoparticles ◽  
Aqueous Environment ◽  
Sunlight Irradiation ◽  
Langmuir Isotherm Model

The unique properties of ZnO nanoparticles have attracted scientists’ interest to produce on a large-scale. Household items, cosmetics, consumer products, and electric sensors are some products that utilize these ZnO nanomaterials. Eventually, ZnO nanoparticles will be released into the environment in various ways. Once released, ZnO nanoparticles would dissociate into Zn2+ ions, which are toxic to aquatic organisms. The presence of humic acid and exposure to sunlight could affect the dissolution of ZnO nanoparticles. Two sizes of commercial ZnO nanoparticles (< 50 nm and < 100 nm) were chosen to study the influence of humic acid and sunlight on the dissolution. In the presence of humic acid, the dissolution of both sizes is higher, with 67 % and 39 % Zn2+ dissolved for < 50 nm and < 100 nm, respectively. The concentration of Zn2+ ions seems to be consistent or stable when exposed to sunlight. However, the humic acid enhanced the release of Zn2+ ions. Langmuir isotherm model best fitted for the humic acid's sorption onto the ZnO nanoparticles with the process been favorable.

scholarly journals Using hypothetical product configurators to measure consumer preferences for nanoparticle size and concentration in sunscreens

2016 ◽  
Vol 2 ◽  
Author(s):  
Amanda S. Barnard ◽  
Jordan J. Louviere ◽  
Edward Wei ◽  
Leon Zadorin
Keyword(s):  
Consumer Preferences ◽  
Metal Oxide Nanoparticles ◽  
Consumer Products ◽  
Future Research ◽  
Potential Toxicity ◽  
Protection Factor ◽  
Demographic Groups ◽  
Type Size ◽  
The One ◽  
Nanoparticle Sizes

Although nanoparticles have been shown to have clear technological advantages, their use in some consumer products remains controversial, particularly where these products come in direct contact with our bodies. There has been much discussion about using metal oxide nanoparticles in sunscreens, and numerous technology assessments aimed at predicting the type, size and concentration of nanoparticles and surface treatments that will be best for consumers. Yet, the optimal configuration is ultimately the one that people actually want and are willing to pay for, but until now consumer preferences have not been included in model predictions. We describe and discuss a proof of concept study in which we design and implement a hypothetical sunscreen product configurator to predict how people tradeoff sun protection factor (SPF), product transparency and potential toxicity from reactive oxygen species (ROS) in configuring their most preferred sunscreen. We also show that preferred nanoparticle sizes and concentrations vary across demographic groups. Our results suggest that while consumers choose to reduce or eliminate potential toxicity when possible, they do not automatically sacrifice high SPF and product transparency to avoid the possibility of toxicity from ROS. We discuss some advantages of using product configurators to study potential product designs and suggest some future research possibilities.

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