Free Radical Produced By Artificial Simulation Organic Polluted Mineral Dust

With the rapid development of society, the environment pollution problems is getting worse.Atmospheric particulate matter has become one of the main environmental factors that affect human health, and the health effect of PM2.5 increasingly aroused people’s concern.Oxidative damage produced by free radicals is considered as one of the important mechanisms of biological toxicity by particles.Strengthening formulate corresponding strategies to prevent and reduce the health hazard of mineral particles is very important. However, the harmful substances adsorption on the surface of atmospheric particulate can induce intracellular free radicals content higher, so the research work of free radical produced by artificial simulation polluted mineral dust of organic pollutants is necessary.The dust objects are quartz, calcite, sodium feldspar, Nano-SiO2 and Nano-CaCO3, organic pollutants objects are BaP, y-HCH and 2,3,7,8-TCDD of this study.To study free radical produced by artificial simulation polluted mineral dust of organic pollutants. The spectrophotometry analysis is used to detect hydroxyl radical (·OH) and active oxygen radicals (ROS) by direct quantitative and relative quantitative way respectively.Concentration and powder-liquid reaction times can seriously affect the free radicals release ability of dust, and the content of radicals generation have a dose-response and time-response relationship.The relationship between the time and the content of hydroxyl radicals in initial stage was accord with logarithmic function. The ability of free radicals generation in the buffer solution by different kinds of mineral is varied.For a long period time (48 h), the The content of hydroxyl radicals generation capacity is calcite>> quartz> albite> Nano-CaCO3> Nano-SiO2, reactive oxygen species generation capacity is calcite≥quartz≥Nano-SiO2> albite>> Nano-CaCO3. The main trend of hydroxyl radicals generation by dust of different mixing ratio is quartz/calcite combination> calcite/albite/ quartz combination> calcite/albite combination>calcite/Nano-CaCO3 combination> quartz/albite combination> quartz/Nano-SiO2 combination.Meanwhile, the calcite/albite combination is abnormal.The hydroxyl radicals generation is different by dust of different mixing ratio. In any proportion, quartz and calcite is in synergy, quartz and albite is in negative synergy, quartz and Nano-SiO2 is in negative synergy, calcite and Nano-CaCO3 show synergy, quartz, calcite and albite show synergy. And calcite and albite combination is in strong synergy when the quantity of two minerals is equal in the mixture,otherwise show negative synergy.Organic pollutants concentration of dust can affect the hydroxyl radical generation.To quarz, Nano-SiO2 and albite, the relationship between the content of hydroxyl radicals and concentration of BaP、 y-HCH and 2,3,7,8-TCDD is accord with positively correlation function,but there is no significant effect for the carbonate minerals. The hydroxyl free radicals and reactive oxygen free radicals can be obviously promoted by the adhesion of BaP,y-HCH and 2,3,7,8-TCDD of quartz dust and Nano-SiO2. The hydroxyl radicals and reactive oxygen free radicals can be promoted by the adhesion of y-HCH of albite. And there is no significant effect on hydroxyl radicals for the carbonate minerals by the adhesion of organic pollutants. Meanwhile, the reactive oxygen free radicals can be promoted by the adhesion of 2,3,7,8-TCDD of calcite and addition of BaP of Nano-CaCO3, and there is a inhibition effect of the adhesion of 2,3,7,8-TCDD of Nano-CaCO3.Organic pollutants type, combination type, species, combination and proportion of dust can make a different degree influence on the release of hydroxyl radicals of dust. For the hydroxyl radicals generation of organic pollutants and single mineral combination, the BaP and y-HCH combination is in synergy, y-HCH and 2,3,7,8-TCDD combination is in negative synergy, BaP and 2,3,7,8-TCDD combination is in synergy to minerals,but in negative synergy to nano particles.For the hydroxyl radicals generation of organic pollutants and variety of minerals combination,BaP and three organic pollutants combination are in synergy,2,3,7,8-TCDD is in negative synergy.One organic pollutants combination can generate different effect because of the different dust proportion and combination. At the same time, the effect action between organic pollutants is different because of the different kinds of dust.The hydroxyl radical generation by rural atmospheric dust is higher than burning before.In different organic/water system, hydroxyl radicals generation ability of organic pollutants is different. The a variety of combination of halogen compound/water system can produce hydroxyl free radicals, and BaP also can generate hydroxyl radicals in the micro environment, meanwhile, γ-HCH and 2,3,7,8-TCDD cannot do.