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Published byKevin Hicks Modified over 8 years ago
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وطني لو شغلت بالخلد عنه نازعتني اليه في الخلد نفسي
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Toxicological aspects of human exposure to nanoparticles Essay By Nashwa Mostafa Mahmoud Demonstrator in forensic medicine & clinical toxicology department Faculty of Medicine, Sohag University
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What is Nano ? Nanometer =10 -9 (3-4 atoms side by side)
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cmmm mm nm 10 -2 10 -3 10 -6 10 -4 10 -5 10 -7 10 -8 10 -9 (m) Hair 100 m Penny 2 cm Raindrop 1 mm Red Blood Cell 5 m What Is A Nanometer?
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80100604020 (nm) Gold Particles 13 nm & 50 nm Flu Virus 100 nm 1 Bacteriophage 60-70 nm DNA Diameter = 2 nm Now Entering The NANO-ZONE
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What is a nanoparticle? Nanoparticles: are particles or materials with one or more dimensions at the nanoscale. Nanoparticles: are particles or materials with one or more dimensions at the nanoscale (< 100 nm). Nanoparticles / Nanomaterials are the building blocks for nanotechnology fullerenes QDs
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Nanotechnology & Nanoscience It is design, characterization, production and application of structures by controlling shape and size at the nanoscale such as molecules and atoms (< 100 nm) such as molecules and atoms
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Nanotechnology Is Not A New Phenomenon The KING Cup: 4 th Century A.D. (The British Museum.) Image of silver/gold nanoparticle (50 nm) Green = Reflected Light Red = Transmitted Light
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Nanotechnology Is Not A New Phenomenon stained-glass windows of the great medieval cathedrals also contain metallic NPs
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Size & Shape Determine Colour Gold NP in glass 25 nm RED 50 nm GREEN 100 nm ORANGE
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Classifications: in volcanoes in volcanoes forest fires, forest fires, dust storms, dust storms, soot, soot, bacteria,virus, dust, bacteria,virus, dust, ocean waves ocean waves According to sources: Natural NPs: volcanoes bacteria virus ocean waves dust storms
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Anthropogenic NPs Diesel and engine exhaust Diesel and engine exhaust Welding fumes, mining combustion by-products, (coal/oil/gas boilers) Indoor pollution: cooking, cigarette, candle smoke, Frying meat, textile fibers, skin particles, spores, dust mites. Incidental NPsIncidental NPs
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in nanotechnology: carbon black, fumed silica, titanium dioxide (TiO2) iron oxide, quantum dots (QDs), fullerenes, carbon nanotubes (CNTs), Engineered NPs: fullerenes CNTs dendrimer QDs
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According to Dimensionality: 1D nanomaterials (NM) ( noanoplate) 1D nanomaterials (NM) ( noanoplate) monolayer films (one atom deep) 2D NM :( Nanorod) 2D NM :( Nanorod) Carbon nanotubes 3D NM :(nanoparticle) 3D NM :(nanoparticle) Dendrimers, Quantum dots Dendrimers, Quantum dots Fullerenes (carbon 60) Fullerenes Carbon nanotubes
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According to NP composition inorganic :metals (iron,titanium, gold, silver) metal oxides (titanium oxide, zinc oxide, silica and iron oxide etc.) organic (fullerenes, CNT, nanopolymers). organic (fullerenes, CNT, nanopolymers). NPs: a single constituent material or be a composite nanomaterials.
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Nanoparticle is everywhere: Information & communication: Information & communication: power engineering power engineering Industrial engineering Industrial engineering Chemical industry Chemical industry Medicine & imaging Medicine & imaging Environmental engineering Environmental engineering Food and Drink Food and Drink Household Household Sports Sports
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Nanotechnology Products Are Here Now Dermatone SPF 20 Natural Formula Kodak Inkjet Photo Papers Nanotec Nanoseal ® Wood Eddie Bauer Ruston Fit Nano-Tex Khakis Hummer H2 Toshiba’s Lithium- Ion Battery Kohler CleanCoat Technology Nanosolar’s Utility Panel™ Socks with Nano Silver
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Unique Properties of Nanoscale Materials Vastly increased surface area per unit mass Iron 100 g Iron: diameter = 3.0 cm Surface area = 26 cm2 100 g Iron: diameter = 50 nm Surface area = 1,500 m2
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Why Is Nanotechnology So Cool? Bulk Gold mp = 1064 ° C Color = gold 1 nm gold particles mp = 700 ° C max = 420 nm Color = brown-yellow 20 nm gold particles mp = ~1000 ° C max = 521 nm Color = red 100 nm gold particles mp = ~1000 ° C max = 575 nm Color = purple-pink Quantum size effects : different mechanical, electronic, photonic, optical, magnetic properties
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Toxicology of Nanoparticles: A Matter of Size? Risk=function( Exposure x toxicity ) Risk=function( Exposure x toxicity ) Potential Human Exposure Routes and Pathways: Inhalation: The principal route of human exposure. Dermal Gastrointestinal Other routes: injection, tissue prothesis Cellular interaction with NPs: Cellular uptake: all types of cells: Mechanisms of toxicity: inflammation, oxidative stress response, disturbed cell function,allergy
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Factors affecting NP Toxicity : Dose: Dose: Dose independent toxicity Dose independent toxicity Size & Surface area: Reduction to the nanoscale increase of surface to volume ratio enhancing the intrinsic toxicity Size & Surface area: Reduction to the nanoscale increase of surface to volume ratio enhancing the intrinsic toxicity Lung inflammation studies – TiO2: 21 nm v. 300 nm inhaled by rats – TiO2: 20 nm v. 250 nm instilled in rats and mice
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Shape, crystal type Toxicity of TiO2 anatase >> TiO2 rutile Chemistry Lung inflammation: (UFP, CNTs, quartz) > TiO2 >MgO In vitro cytotoxicity: Fe2O3 = asbestos > ZnO > TiO2 = ZrO2
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Health Hazards of NPs: Inhalation Exposure Studies with NM Inhalation Exposure Studies with NM NPs can enter lung tissues and be distributed to other organs and tissuesNPs can enter lung tissues and be distributed to other organs and tissues NPs not captured by respiratory defense systemsNPs not captured by respiratory defense systems Observed effects: impaired macrophage clearance, inflammation, epithelial cell proliferation, fibrosis, emphysema, appearance of tumorsObserved effects: impaired macrophage clearance, inflammation, epithelial cell proliferation, fibrosis, emphysema, appearance of tumors
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GIT uptake of NPs: NPs found in colon tissue of patients with cancer, Crohn ’ s, ulcerative colitis
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Dermal uptake of NPs: Reports of penetration of intact skin in test system models by: Reports of penetration of intact skin in test system models by: –Multi-walled carbon nanotubes –Substituted fullerenes –Quantum dots Titanium dioxide NPs, used as a sunscreen were observed to catalyze DNA damage both in vitro and in vivo Titanium dioxide NPs, used as a sunscreen were observed to catalyze DNA damage both in vitro and in vivo
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Nervous system uptake of NPs:Nervous system uptake of NPs: Yes or no Yes or no Neuronal uptake of inhaled NPs :via olfactory nerves or/and BBB Neuronal uptake of inhaled NPs :via olfactory nerves or/and BBB Experimental evidence : Experimental evidence : neurodegenerative diseases, such as Alzheimer ’ s disease, Parkinson ’ s disease, Pick ’ s disease, are associated with oxidative stress and accumulation of metals (like copper, aluminum, zinc, but especially iron) in brain regions associated with function loss and cell damage neurodegenerative diseases, such as Alzheimer ’ s disease, Parkinson ’ s disease, Pick ’ s disease, are associated with oxidative stress and accumulation of metals (like copper, aluminum, zinc, but especially iron) in brain regions associated with function loss and cell damage
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Positive effects of NPs: Antioxidants: Fullerene Derivatives have neuroprotective properties and antiapoptotic activity. Antioxidants: Fullerene Derivatives have neuroprotective properties and antiapoptotic activity. Anti-microbial activity: antimicrobial effect, such as silver, titanium dioxide, fullerenes, zinc oxide, and magnesium oxide Anti-microbial activity: antimicrobial effect, such as silver, titanium dioxide, fullerenes, zinc oxide, and magnesium oxide
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Strategies to control exposure to NPs: Useful measures at work : Total enclosure of the process Total enclosure of the process Limitation of numbers of workers Limitation of numbers of workers Partial enclosure with local exhaust ventilation Partial enclosure with local exhaust ventilation Local exhaust ventilation Local exhaust ventilation General ventilation Reduction in periods of exposure General ventilation Reduction in periods of exposure Regular cleaning of wall and other surfaces Use of suitable personal protective equipment Regular cleaning of wall and other surfaces Use of suitable personal protective equipment Prohibition of eating and drinking Prohibition of eating and drinking
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Number Metric methods: Optical Particle Counter Condensation particle counter Scanning mobility particle sizer (SMPS) Electrical low pressure impactor (ELPI) Surface area Metric methods: Epiphaniometer BET bulk analysis Image analysis Metric methods: scanning (SEM) or transmission electro-microscopes (TEM): Analysis of morphology. Samples may be collected by personal samplers or size selective static samplers. Detection and Measurements of NPs: Condensatio n particle counter
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Conclusion: Nanotechnolog is a nanocoin
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