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[Research on the relationship between environmental chemical pollutant exposure and epigenetics].
Rui, QY, Li, X, Zhang, HB, Guo, XM, Zheng, N, Zhao, L, Guo, LQ, Li, PH, Yue, JJ
Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases. 2020;(3):237-240
Abstract
Environmental chemical pollutants are increasing, which brings various harms to human health. Epigenetics may be an important medium between exposure to environmental chemical contaminants and adverse health effects. Many environmental chemical pollutant exposures can regulate gene expression and promote disease occurrence and development through epigenetic mechanisms. This review outlines the mechanisms of epigenetics and the latest research advances in exposure and epigenetics of several environmental chemical substances (heavy metal arsenic, bisphenol A, dioctyl phthalate and benzene). To further understand and study the relationship between environmental chemical pollutant exposures and epigenetics in order to elucidate the mechanisms of disease occurrence and development.
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2.
Food components and environmental chemicals of inhibiting human placental aromatase.
Wang, Y, Pan, P, Li, X, Zhu, Q, Huang, T, Ge, RS
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 2019;:46-53
Abstract
Human placental CYP19A1 catalyzes the estrogen synthesis from androgens. The enzyme is encoded by CYP19A1 gene located in chromosome 15q21. This enzyme is a monooxygenase in the smooth endoplasmic reticulum. The various promoters of the CYP19A1 gene determine its expression in different tissues and the distal promoter I.1 controls its expression in the placenta and retinoids can regulate the expression. Many food components and environmental chemicals inhibit CYP19A1 activity via different modes of action. These chemicals include gossypol, flavones, flavanones, chalconoids, resveratrol, and tobacco alkaloids derived from foods as well as phthalates, insecticides, fungicides, and biocides in the contaminated foods. The inhibition of placental CYP19A1 could impair pregnancy.
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Suppression of dioxins in waste incinerator emissions by recirculating SO2.
Lin, X, Zhan, M, Yan, M, Dai, A, Wu, H, Li, X, Chen, T, Lu, S, Yan, J
Chemosphere. 2015;:75-81
Abstract
Sulphur is an effective inhibitor of the formation of Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans (PCDD/Fs), as was proven in laboratory and pilot plant studies. In this study, a pilot-scale system with capacity 300 N m(3) h(-1) was situated at the bypass of an actual hazardous waste incinerator (HWI) and tested to reduce the emission of PCDD/Fs. Activated carbon was used as a medium to adsorb SO2 from flue gas and release it again at the higher temperature of filtered ash detoxification to achieve SO2 circulation in the system. Most PCDD/Fs in the filtered ash are decomposed by thermal treatment. Experimental results indicate that the system is capable of stable operation with SO2 accumulation at a high level of concentration and a high reduction efficiency of PCDD/Fs. A reduction of more than 80% was already achieved without addition of other sulphur compounds. When pyrite (FeS2) was added the reduction of PCDD/Fs could reach 94%, with a residual PCDD/Fs concentration in the flue gas as low as 0.13 ng TEQ N m(-3). This SO2 recirculating and suppression technology potentially provides significant progress for dioxin emission control in waste incineration and could be useful for controlling emissions of PCDD/Fs and other chlorinated organic chemicals in China.
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4.
Role of hydrodynamic drag on microsphere deposition and re-entrainment in porous media under unfavorable conditions.
Li, X, Zhang, P, Lin, CL, Johnson, WP
Environmental science & technology. 2005;(11):4012-20
Abstract
Deposition and re-entrainment of 1.1 microm microspheres were examined in packed glass beads and quartz sand under both favorable and unfavorable conditions for deposition. Experiments were performed at environmentally relevant ionic strengths and flow rates in the absence of solution chemistry and flow perturbations. Numerical simulations of experimental data were performed using kinetic rate coefficients to represent deposition and re-entrainment dynamics. Deposition rate coefficients increased with increasing flow rate under favorable deposition conditions (in the absence of colloid-grain surface electrostatic repulsion), consistent with expected trends from filtration theory. In contrast, under unfavorable deposition conditions (where significant colloid-grain surface electrostatic repulsion exists), the deposition rate coefficients decreased with increasing flow rate, suggesting a mitigating effect of hydrodynamic drag on deposition. Furthermore, the re-entrainment rate was negligible under favorable conditions but was significant under unfavorable conditions and increased with increasing flow rate, demonstrating that hydrodynamic drag drove re-entrainment under unfavorable conditions. The drag torque resulting from hydrodynamic drag was found to be 1 order of magnitude or more lower than the adhesive torque based on pull-off forces from atomic force microscopy measurements. This result indicates that hydrodynamic drag was insufficient to drive re-entrainment of microspheres that were associated with the grain surface via the primary energy minimum and suggests that hydrodynamic drag drove re-entrainment of secondary-minimum-associated microspheres.