| Nanomaterials are powdered or lumped natural or artificial materials with dimensions between 1 nm and 100 nm in one or more dimensions.Nanomaterials have been widely used in various fields such as mechanics,electricity and magnetism due to their unique effects,such as surface effect,small size effect and quantum size effect.This,however,brings up another concem.Namely,in the process of production,transportation and use,nanomaterials will inevitably enter the environment(such as atmosphere and water)in a variety of ways,and pose great risks to human health through a variety of exposure ways.Therefore,the study of the environmental health safety of nanomaterials,especially the assessment of the effects on human health,is of great importance to reveal the potential health risks in the environment,provide guidance for the formulation of environmental pollutant emission standards,and promote the sustainable development of nanotechnology and its related industries.The purpose of this paper is to evaluate the toxicity of nanocomposite pollutants in the environment and explore their possible mechanisms through the nanoparticle library,so as to provide theoretical support for the interpretation of related toxic effects.Therefore,the first part of this paper aims to clarify the key role of nuclear materials in PM2.5 induced cytotoxicity by exploring the PM2.5 model particle library based on silicon and carbon.The most toxic part of PM2.5 particles is the insoluble nuclear material which adsorbs pollutants.Carbon and silicon dioxide have markedly different physical and chemical properties,for example,silicon dioxide is more polar than carbon black.This may give them unique physical,chemical and biological activities.However,the difference between carbon and silica cores in causing toxicity is unknown.Using the method of nanoparticle library,we prepared PM2.5 model particle library containing 32 kinds of particles based on carbon and silicon.Each particle is loaded with one or more toxic air pollutants,including Cr(VI),As(Ⅲ),Pb2+,and BaP,at an environmentally relevant concentration.The PM2.5 model particle library was used to explore their contribution to the cytotoxicity of normal human bronchial cells.The results show that:1)Silicon-based and carbon-based nanoparticles have different adsorption capacities for pollutants with different physical and chemical properties.The polar pollutants(such As Cr(Ⅵ),As(Ⅲ)and Pb2+)are more adsorbed by Nanomaterials are powdered or lumped natural or artificial materials with dimensions between 1 nm and 100 nm in one or more dimensions.Nanomaterials have many unique effects,such as surface effect,small size effect and quantum size effect,because the size of nanomaterials is between the microscopic atomic and molecular structure and the macroscopic system.This makes nanomaterials show many unique physical and chemical properties different from other materials in mechanics,electricity,magnetism and other aspects,which also makes nanomaterials get a wide range of applications in various fields.In the field of biomedicine,it is used in drug delivery,therapy,in vitro diagnosis,in vivo detection and contrast imaging.Application in environmental engineering,mainly for the various shapes and different forms of nanometer materials in the atmosphere and waste water by filtration and adsorption process,mainly because the nanometer material has high specific surface area and hence the high reactivity,adsorbent and catalyst role,is widely used in the detection and removal of toxic and harmful chemicals and biological material(such as viruses,bacteria,parasites and antibiotics,etc.);In the direction of energy,multifunctional nano materials because of its excellent electrical conductivity and thermal conductivity,large surface area and chemical stability,in energy production,energy conversion,energy storage,energy conservation and energy transmission plays a key role in the application,the new nano technology can make full use of the rich,"green" energy such as solar energy,mechanical energy and thermal energy,is to meet our long-term energy needs and the effective ways to achieve sustainable environmental development.Although nanomaterials have been widely used in many fields due to their unique physical and chemical properties,it also brings another problem that we need to pay attention to.Namely,in the process of production,transportation and use,nanomaterials will inevitably enter the environment(such as atmosphere and water)in a variety of ways,and pose great risks to human health through a variety of exposure ways.Therefore,the study of the environmental health safety of nanomaterials,especially the assessment of the effects on human health,is of great importance to reveal the potential health risks in the environment,provide guidance for the formulation of environmental pollutant emission standards,and promote the sustainable development of nanotechnology and its related industries.Therefore,the first part of this paper aims to clarify the key role of nuclear materials in PM2.5 induced cytotoxicity by exploring the PM2.5 model particle library based on SiO2 and carbon.The most toxic part of PM2.5 particles is the insoluble nuclear material which adsorbs pollutants.Carbon and SiO2 have markedly different physical and chemical properties,for example,SiO2 is more polar than carbon black.This may give them unique physical,chemical and biological activities.However,the difference between carbon and SiO2 cores in causing toxicity is unknown.A PM2.5 model library containing 32 kinds of particles based on carbon and silicon was prepared by using a nanocomposite chemistry strategy and a reductionistic approach.Each particle is loaded with one or more toxic air pollutants,including Cr(Ⅵ),As(Ⅲ),Pb2+,and BaP,at an environmentally relevant concentration.The PM2.5 model particle library was used to explore their contribution to the cytotoxicity of normal human bronchial cells.The results showed as follows:1)PM2.5 particles were similar to PM2.5-JN particles in morphology,hydration dynamic diameter and Zeta potential of carbon and SiO2 based models;2)SiO2-based and carbon-based nanoparticles have different adsorption capacities for pollutants with different physical and chemical properties.The polar pollutants(such as Cr(Ⅵ),As(Ⅲ)and Pb2+)are more adsorbed by SiO2,while the non-polar pollutants(such as BaP)are more adsorbed by carbon.3)Carbon-based and silicon-based model particles have different ability to penetrate human cells.In 16HBE cells,the cell uptake rate of carbon-based particles is about 41%higher than that of SiO2-based particles.4)SiO2-based model PM2.5 particles have greater cytotoxicity than carbon-based particles due to Cr.Except for Cr(Ⅵ),SiO2 induced toxicity is 59%lower than carbon-based particles.After loading Cr(Ⅵ),the situation was reversed(the toxicity of SiO2 particles was 56%higher);5)Compared with stable SiO2,carbon particles,as a reducing agent of Cr(Ⅵ),can reduce Cr(Ⅵ)to less toxic Cr(Ⅲ),thus reducing the contribution of Cr to cytotoxicity.Our results highlight the different roles of carbon and SiO2 cores in inducing the health risks of PM2.5 particles.In this study,we synthesized SiO2 or carbon core containing pollutants(Cr(Ⅵ),As(Ⅲ),Pb2+and BaP)loaded model PM2.5 particle libraries to identify the effects of carbon core or SiO2 on the loading of various pollutants,and further study the resulting PM2.5-cell interactions.These results suggest that the main toxic components of PM2.5 may be different,depending on whether the different core material is carbon or SiO2.Specifically,carbon cores can partially reduce the toxicity of oxidizing pollutants such as Cr(Ⅵ),but the initial high toxicity of carbon nanoparticles is evident.At the same time,the health risks of SiO2 particles are mainly due to the high toxicity of the contaminants contained.The results can help reveal the potential health risks of PM2.5 in air from different sources and provide guidance for the formulation of emission standards for air pollutants.The second part of this paper is the study of organ damage and distribution in zebrafish after combined exposure of two-dimensional nanosheets and PFAS.Nanotechnology is evolving all the time,and with the mass production and use of nanomaterials,they will inevitably be discharged or leaked into the aquatic environment.Various potential artificial channels,such as nanotechnology waste,oil refineries,automobile traffic,domestic drainage systems,boats,etc.,can add nanomaterials to rivers.Given the seriousness of water pollution in aquatic environments,nano material has a wider range of mobility,easy and persistent organic matter existing in water environment PFAS(perfluorinated alkyl and multiple fluorine alkyl substances)form may be even more devastating compound pollutants,the compound pollution of biological safety evaluation is significant to human health.Therefore,this study will evaluate the environmental health risks of nanomaterials and their composite pollutants in water environment.In this section,we selected two kinds of MoS2 and WS2 nanoparticles,with seven different PFAS[trifluoroacetic acid(C2HF302),five fluoride(C3HF502)propionate,perfluorinated pentanoic acid(C5HF902),perfluorinated butyl sulfonic acid potassium(C4HF9KO3S),13sulfonic acid potassium fluoride hexane-1(C6F13KO3S),perfluorinated octyl(C8F17KO3S)and perfluorinated sulfonic acid potassium acid(C8H4F15NO2)]application of combinatorial chemistry strategy composite respectively,obtained contains two kinds of pure piece of 16 kinds of nano compound pollutants.In vitro cell experiments were used to screen out two nanocomposite pollutants with high toxicity,molybdenum disulfide-potassium perfluorooctane sulfonate and molybdenum disulfide-ammonium perfluorooctanoate,and then nanocomposite pollutants with different concentration gradients were designed to evaluate their organotoxicity and in vivo distribution to adult zebrafish.In this section,we select MoS2 and WS2 nanotubes with seven different PFAS composite respectively,combinatorial chemistry application strategy and in vitro cell screening of MoS2 bigger toxicity experiment and perfluorinated octane sulfonic acid potassium and total acid ammonium compound respectively,designed the low and high concentrations of nano complex organs of adult zebrafish to evaluate toxicity and distribution in the body.The results showed that the intake of MoS2 was high in the intestine and liver of zebrafish in the MoS2 and potassium perfluorooctane sulfonate compound group,while the intake of MoS2 and ammonium perfluorooctanoate compound group was low.Through molecular simulation,the mechanism is explained as follows:the mixed system of MoS2 and PFOS has a strong destructive force on the phospholipid membrane,causing serious damage to the intestinal mucosa of zebrafish,leading to the entry of a large amount of MoS2.However,the mixed system of MoS2 and PFOA is less destructive to the membrane,and the intestinal mucosa of zebrafish maintains a relatively good integrity,which makes the intestinal barrier block the entry of MoS2.MoS2,potassium perfluorooctane sulfonate and ammonium perfluorooctanoate alone and combined exposure can cause different degrees of oxidative damage to the intestinal tract and liver of zebrafish,and the toxic effect of combined exposure to the intestinal tract and liver of zebrafish is stronger.The results showed that SOD enzyme activity was activated at a higher level in the compound exposure group,which indicated that the intestinal tract and liver of zebrafish in the compound exposure group had a stronger antioxidant reaction,which was used to maintain the oxidation-antioxidant balance in vivo.CAT activity was significantly inhibited,which reflected that when the toxin production effect of pollutants was greater than the detoxification effect of the fish itself,the activity of antioxidant enzymes continued to decrease,causing more serious damage to the body.MDA content significantly increased,indicating that the degree of lipid peroxidation in the intestinal tract and liver was more serious in the combined exposure group.In summary,we studied the environmental health effects and their mechanisms of nanocomposite pollutants in the atmosphere and water using combinatorial chemistry strategies.The relationship between environmental compounds and toxic effects was established,which also provided theoretical support for explaining the mechanism of toxic effects.Study of environmental health and safety of nanomaterials,especially for human health effect of evaluation,is very important to find out the potential health risks in the environment,but also for environmental pollutant emission standards and guide the safety assessment of nanometer materials,to promote the sustainable development of nanotechnology and its related industries has an important meaning,the biological safety evaluation of compound pollution has a great significance on human health. |
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