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1.
Sci Rep ; 10(1): 479, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31949216

RESUMO

Air pollution is a major environmental health problem. The study of interaction between air pollution and human will benefit to the human health and well-being of community. Both a model for assessing population relative risk of air pollution exposure (MAPRRAPE) and air pollution concentration methods were applied in a case study to determine the optimal method in evaluating risk of population exposure to Sulfur Dioxide (SO2). The framework for building the MAPRRAPE was described in detail. Then, the spatial patterns of population by demographic characteristics exposed to SO2 from industrial, vehicle, and the mixture of industrial and vehicle pollution sources, as well as an in-depth quantitative investigation using correlation analysis were studied for further source appointment. The results showed that the MAPRRAPE was more reliable than air pollution concentration model in determining population exposure risks by demographic characteristics. The high risk areas of whites exposed to SO2 were larger than blacks and the other races due to a large number of whites, and other age groups exposed to SO2 were larger than children and the old people. In addition, the correlation analyses showed that the relative risks of population by demographic characteristics exposed to SO2 had a more significant correlation with vehicle pollution source than industrial pollution source. The results of source appointment thus demonstrated that vehicle pollution source was the main pollution source. This study suggests that there is a clear need for the implementation of programs and services that will reduce population exposed to air pollution with focusing on densely populated areas for an ultimate improvement of community health status and the environmental conditions.

2.
Sci Rep ; 9(1): 16386, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31704977

RESUMO

Heavy metal pollution in the air, water, and soil has attracted substantial interest recently; however, assessment of the total human environmental exposure remains limited. Therefore, determining the total human environmental exposure is imperative for the management and control of heavy metal pollution. This study assessed the total environmental exposure levels of heavy metals as well as the exposure contributions of air, water, and soil, focusing on Hg, Cd, As, Pb, and Cr. Data from 3,855 volunteers from the cities of Taiyuan, Dalian, Shanghai, Wuhan, Chengdu, and Lanzhou allowed for comparison of the exposures in urban and rural areas. The levels of total human environmental exposure of Hg, Cd, As, Pb, and Cr were 1.82 × 10-6 mg/(kg·d), 1.58 × 10-6 mg/(kg·d), 3.87 × 10-5 mg/(kg·d), 1.79 × 10-5 and 7.47 × 10-5 mg/(kg·d), respectively. There were regional, urban-rural, sex, and age differences in the levels of heavy metal exposure. Water pollution was determined to be the largest contributor to heavy metal exposure, accounting for 97.87%, 92.50%, 80.51%, 76.16% and 79.46% of the Hg, Cd, As, Pb, and Cr, followed by air and soil pollution. These results can provide data to inform environmental protection policies and identify the priority pollutants that can help identify and prevent health risks due to overexposure to these heavy metal pollutants.

3.
Eur J Nutr ; 2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30854593

RESUMO

PURPOSE: Accurate data on water and beverage intakes are essential for assessing hydration adequacy and setting proper guidelines. The objective of this study is to identify the patterns and sociodemographic determinants of water intake and to assess the intake adequacy for children in China. METHODS: The study team recruited 41,439 children aged 6-17 years using a multi-stage cluster random sampling method. Daily water and beverage intakes were investigated with the standard questionnaires and measuring containers in face-to-face interviews. Each participant was assigned an adjustment weight to obtain a nationally representative sample. Sociodemographic factors influencing water intake were identified using multi-variable regressions. Water intake adequacy was evaluated by comparing with the recommended water intake (RWI). RESULTS: The mean ± standard deviation of total water intake (TWI) was 1603 ± 731 mL/day for boys and 1487 ± 661 mL/day for girls. Plain water, food moisture, and other beverages contributed 51%, 20%, and 29% of the TWI. Multi-variable analyses showed that TWI of children increased with age, in urban areas and day schools, and with parents' economic and educational levels. The majority (82%) of children had TWI not meeting the corresponding RWI, and the percentage increased with age except for 14-17-year-old boys. CONCLUSIONS: Plain water is still the major source of daily water intake by children in China. Unfortunately, the majority of children do not have sufficient water intake, which warrants future actions and guidelines targeting adequate hydration.

4.
Environ Int ; 125: 529-541, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30612707

RESUMO

As a critical air pollutant, PM2.5 is proved to be associated with numerous adverse health impacts and pose serious challenges to human life. This situation is especially important for China as the most populous and one of the heaviest PM2.5 polluted country in the world. However, health burden estimations reported for China in previous studies may be biased due to the usage of PM2.5 concentrations at a coarsely spatial resolution, as well as the ignorance of the spatial discrepancies of parameters (e.g. respiratory rate) employed in the exposure-response function. This study therefore utilized a hybrid remote sensing-geostatistical approach to refine PM2.5 concentrations at 1 km resolution across mainland China from 2013 to 2017. Meanwhile, nationwide exposure parameters were for the first time introduced to weight the integrated exposure response (IER) function to calculate and spatially reallocate the corresponding PM2.5-attributable premature deaths at 1 km resolution. Results showed that annually averaged PM2.5 concentrations in mainland China decreased by 39.5%, from 59.1 µg/m3 in 2013 to 35.8 µg/m3 in 2017. Subsequently, PM2.5 attributable premature deaths reduced 12.6%, from 1.20 million (95% CI: 0.57; 1.71) in 2013 to 1.05 million (95% CI: 0.44; 1.44) in 2017. This declining trend was found in most parts of China except some areas in Xinjiang, Jilin, and Heilongjiang provinces. As a result, 214,821 (95% CI: 96,675; 302,897) life were saved with an estimated monetary value of US$ 210.14 billion (2011 values). However, it has to be acknowledged that, the central and northern China within priority areas of air pollution control were still experiencing high numbers of premature deaths due to the severe PM2.5 pollution and high-density population. But more worrying than these priority areas are those Harbin-Changchun Metropolitan Region, City Belt in Central Henan and Yangtze-Huaihe City Belt in non-priority areas, which also have been seriously suffering PM2.5 attributable premature deaths over 28, 000 cases per year. In conclusion, despite the huge gain in life-saving effects in China over the past five years with the help of air pollution intervention policy, future work on cleaner air and better human health is still strongly needed, especially in non-priority areas of air pollution control.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , China , Cidades , Humanos , Mortalidade Prematura , Tecnologia de Sensoriamento Remoto
5.
Sci Total Environ ; 650(Pt 2): 2545-2558, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30293007

RESUMO

To investigate the pollution characteristics and potential sources in a dusty season, an online analyzer was used to measure trace gases and major water-soluble ions in PM10 from April 1st to May 29th, 2011 in Lanzhou. The average concentrations of HONO, HNO3, HCl, SO2 and NH3 were 0.93, 1.16, 0.48, 9.29 and 5.54 µg/m3, respectively, and 2.8, 2.76, 8.28 and 2.48 µg/m3 for Cl-, NO3-, SO42- and NH4+. In the non-dust period, diurnal variations of SO42-, NO3- and their gaseous precursors showed similar change trend. NH4+ showed unimodal pattern whereas NH3 illustrated a bimodal pattern. HCl and Cl- showed an opposite diurnal pattern. In the dust event, temporal profiles of HCl and Cl-, SO2 and SO42- all presented similar change trend, and SO42- and Cl- preceded dust ions (Ca2+ and Mg2+) 13 h. The ratios of NO3- to SO42- were 0.65 in the non-dust period and 0.31 in the dust event. In the dust event, the sulfur oxidation ratio (SOR) was a factor of 1.33 greater than that in the non-dust period, and [SO42-]/[SO2] was 2.31 times of that in the non-dust period. The source apportionment using Probabilistic Matrix Factorization (PMF) suggested that fugitive dust (58.09%), secondary aerosols (33.98%), and biomass burning (7.93%) were the major sources in the non-dust period whereas dust (67.01%), salt lake (29.68%), biomass burning (0.8%), and motor vehicle (2.51%) were the primary sources in the dust event. Concentration weighted trajectory (CWT) model indicated that NO3-, Cl- and K+ could be regarded as local source species, the potential sources of Na+, Mg2+ and Ca2+ concentrated in the two large areas with the one covered in the junction areas of Xinjiang, Qinghai and Gansu and another one covered the places around in Lanzhou, the potential sources of SO42- were mainly localized in the areas adjacent to Lanzhou.

6.
Chemosphere ; 184: 866-878, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28646769

RESUMO

The metal(loid) pollution still is a great concern due to the effects from urbanization and industrialization. While, the health risks from the toxic metal(loid)s could decrease if strict pollution control measures were adopted. However, few studies to date investigate the health risks of heavy metal(loid)s in a systematic river basin for the dependent residents, after taking pollution control measures. Thus, the contents of metal(loid)s (Cu, Pb, Zn, Cd, Mn, As) in surface water along a typical river basin were investigated in this study, and the potential non-carcinogenic and carcinogenic health risks posed to the residents were assessed. Although the soluble contents of Cu, Pb, Zn and Cd exceeded the respective thresholds in two sites located downstream the mine area, they were greatly decreased in comparison with previous contamination levels, and the soluble concentrations of all the metal(loid)s were within the relevant thresholds in the sites far away from the mining area. Moreover, the closer to the mining area, the higher the pollution levels of metal(loid)s. The total hazard index for non-carcinogenic risks of metal(loid)s were basically lower than the threshold (1) for the local population. Whereas, although the content of metal(loid)s were low (such as As), they could pose relative higher non-carcinogenic health risks. The result illustrated that pollution levels, toxicity of the contaminants and exposure behavior patterns all could contribute to the potential detrimental health risks. Additionally, the non-carcinogenic and carcinogenic risks from ingestion exposure were ∼2-∼4 orders of magnitude higher than those from dermal contact. The total carcinogenic risks were basically lower than the maximum tolerable levels (1.0 × 10-4), indicating carcinogenic risks from most areas of the river could also be accepted. Among different population groups, heavy metal(loid)s posed relative higher non-carcinogenic and carcinogenic risks to the children in 0-5 years old. Fortunately, the surface water in most area of this basin is safe in usage for the local population and the health risks were basically acceptable in case exposed to the target metal(loid)s, after the river basin was in the charge of strict pollution control measures.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Poluição Ambiental/estatística & dados numéricos , Mineração , Criança , China , Exposição Ambiental/análise , Exposição Ambiental/prevenção & controle , Monitoramento Ambiental , Poluição Ambiental/análise , Poluição Ambiental/prevenção & controle , Intoxicação por Metais Pesados , Humanos , Metaloides , Metais Pesados/análise , Envenenamento , Medição de Risco , Rios
7.
Sci Rep ; 7(1): 341, 2017 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-28336966

RESUMO

Traditional sampling for soil pollution evaluation is cost intensive and has limited representativeness. Therefore, developing methods that can accurately and rapidly identify at-risk areas and the contributing pollutants is imperative for soil remediation. In this study, we propose an innovative integrated H-G scheme combining human health risk assessment and geographical detector methods that was based on geographical information system technology and validated its feasibility in a renewable resource industrial park in mainland China. With a discrete site investigation of cadmium (Cd), arsenic (As), copper (Cu), mercury (Hg) and zinc (Zn) concentrations, the continuous surfaces of carcinogenic risk and non-carcinogenic risk caused by these heavy metals were estimated and mapped. Source apportionment analysis using geographical detector methods further revealed that these risks were primarily attributed to As, according to the power of the determinant and its associated synergic actions with other heavy metals. Concentrations of critical As and Cd, and the associated exposed CRs are closed to the safe thresholds after remediating the risk areas identified by the integrated H-G scheme. Therefore, the integrated H-G scheme provides an effective approach to support decision-making for regional contaminated soil remediation at fine spatial resolution with limited sampling data over a large geographical extent.


Assuntos
Metais Pesados/análise , Medição de Risco/métodos , Poluentes do Solo/análise , Solo/química , Carcinógenos/análise , China , Humanos , Análise Espacial
8.
Chemosphere ; 147: 404-11, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26774306

RESUMO

Rapid development of industrialization and urbanization results in serious environmental contamination by metal(loid)s, which would consequently cause deleterious health effects to the exposed people through multi-pathways. Therefore, total health risk assessment for the population in urban environment is very important. Unfortunately, few studies to date investigate the cumulative health risks of metal(loid)s through aggregative pathways in Children who are often susceptible population. 12 metal(loid)s including Lead(Pb), Cadmium(Cd), Arsenic(As), Chromium(Cr), Zinc(Zn), Copper(Cu), Nickel(Ni), Manganese(Mn), Cobalt(Co), Selenium(Se), Antimony(Se) and Vanadium(V), were analyzed in PM10, drinking water, food, soil and indoor dust in this study. The cumulative and aggregative risks of these metal(loid)s among the local children were then evaluated on a field sampling and questionnaire-survey basis. The results showed that the environments were heavily polluted by metal(loid)s. For most metal(loid)s, food ingestion accounted for more than 80% of the total daily exposure dose. The non-cancer risks were up to 30 times higher than the acceptable level due to the food ingestion via Pb, Cr, Cu, Zn, As, Se, Cd and Sb, and the PM10 inhalation via Cr and Mn. While, the cancer risks were mainly attributed to Cr via food ingestion and As via food and dust ingestion, and approximately 100 times of the maximum acceptable level of 1.0 × 10(-4). The study highlights the cumulative and aggregative exposure assessment, instead of pollutant investigation to evaluate the potential health risks and emphasizes concerns to improve indoor hygienic and environmental quality and to decrease the potential harmful health effects of children living in urban area.


Assuntos
Arsênico/análise , Exposição Ambiental/análise , Metais/análise , Poluição do Ar em Ambientes Fechados/análise , Criança , Pré-Escolar , China , Cidades , Água Potável/análise , Poeira/análise , Feminino , Contaminação de Alimentos/análise , Humanos , Masculino , Material Particulado/análise , Medição de Risco , Poluentes do Solo/análise , Poluentes Químicos da Água/análise
9.
Sci Total Environ ; 548-549: 6-12, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26799802

RESUMO

Exposure to PM2.5 is a leading environmental risk factor for many diseases and premature deaths, arousing growing public concerns. In this study, indoor and outdoor PM2.5 concentrations were investigated during the heating and non-heating seasons in an urban area in northwest China. Personal inhalation exposure levels among different age groups were evaluated, and the difference attributable to different cooking fuels including coal, gas and electricity, was discussed. The average concentrations of PM2.5 in the kitchen and the bedroom were 125±51 and 119±64µg/m(3) during the heating season, and 80±67 and 80±50µg/m(3) during the non-heating season, respectively. Indoor PM2.5, from indoor combustion sources but also outdoor penetration, contributed to about 75% of the total PM2.5 exposure. Much higher indoor concentrations and inhalation exposure levels were found in households using coal for cooking compared to those using gas and electricity. Changing from coal to gas or electricity for cooking could result in a reduction of PM2.5 in the kitchen by 40-70% and consequently lower inhalation exposure levels, especially for children and women.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Culinária/métodos , Características da Família , Exposição por Inalação/estatística & dados numéricos , Material Particulado/análise , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , China , Monitoramento Ambiental , Humanos
10.
Phys Chem Chem Phys ; 17(9): 6406-14, 2015 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-25656925

RESUMO

Metal nanoparticles embedded in hollow materials are important due to their wide applications in catalysis. In this work, we disclosed a nontraditional synthetic pathway to prepare silica hollow nanospheres by hydrothermal treatment in the presence of compressed CO2. Especially, the silica hollow nanospheres with an outer diameter of about 16 nm and an inner pore size of 7 nm were obtained using 1.0 MPa CO2. The formation mechanism of silica hollow nanospheres induced by CO2 was investigated by high-pressured UV/Vis spectroscopy. Moreover, gold nanoparticles (2.5 nm) embedded in the silica hollow nanospheres were prepared by a one-pot synthesis using HAuCl4 as a precursor. The current synthetic route of nano-catalysts was simple and facile, in which no etching agent was needed in the process of the hollow material preparation. Besides, this nano-catalyst showed an excellent catalytic performance in epoxidation of styrene with high conversion (82.2%) and selectivity (90.2%) toward styrene oxide, as well as in the selective oxidation of ethylbenzene with good conversion (26.6%) and selectivity (87.8%) toward acetophenone. Moreover, the Au nanoparticles (AuNPs) embedded in silica hollow nanospheres exhibited an excellent recyclability in both the oxidation reactions.


Assuntos
Dióxido de Carbono/química , Ouro/química , Nanopartículas Metálicas , Dióxido de Silício/química , Catálise , Microscopia Eletrônica de Transmissão , Oxirredução
11.
Environ Pollut ; 200: 16-23, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25686884

RESUMO

Manufacture of lead-acid batteries is of widespread interest because of its emissions of heavy metals and metalloids into environment, harming environmental quality and consequently causing detrimental effects on human health. In this study, exposure pathways and health risks of children to heavy metal(loid)s (Pb, Cd, As, etc) were investigated based on field sampling and questionnaire. Pb was one of the most abundant elements in children's blood, with an elevated blood lead level of 12.45 µg dL(-1). Soil/dust and food were heavily polluted by targeted metal(loid)s. Food ingestion accounted for more than 80% of the total exposure for most metal(loid)s. The non-cancer risks to children were 3-10 times higher than the acceptable level of 1, while the cancer risks were 5-200 times higher than the maximum acceptable level of 1.0 × 10(-4). The study emphasized the significance of effective environmental management, particularly to ensure food security near battery facilities.


Assuntos
Fontes de Energia Elétrica , Exposição Ambiental/estatística & dados numéricos , Metaloides/análise , Poluentes do Solo/análise , Criança , China , Poeira/análise , Poluição Ambiental/estatística & dados numéricos , Humanos , Resíduos Industriais/análise , Resíduos Industriais/estatística & dados numéricos , Chumbo , Metais/análise , Medição de Risco , Solo
12.
Environ Pollut ; 199: 18-25, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25617855

RESUMO

As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis.


Assuntos
Exposição Ambiental/análise , Poluição Ambiental/estatística & dados numéricos , Intoxicação por Chumbo/urina , Chumbo/urina , Criança , Coque , Exposição Ambiental/estatística & dados numéricos , Poluição Ambiental/análise , Humanos , Isótopos/análise , Chumbo/análise
13.
J Environ Sci (China) ; 26(2): 432-9, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25076535

RESUMO

Sixteen polycyclic aromatic hydrocarbons (PAHs) were determined in 24 duplicate-diet samples from people in Taiyuan during summer and winter in 2009. Dietary intake of PAHs for 2862 participants was subsequently estimated by a survey in Taiyuan. Results from these 24 samples were compared with a raw food study in Taiyuan in 2008. Three main sources of dietary PAHs are vegetables, wheat flour and fruits, the sum of which contributes 75.95% of PAHs in dietary food. Compared to the estimated value in raw food, much more B[a]P(eq) (benzo[a]pyrene equivalents) were detected in food samples collected in the duplicate-diet study in Taiyuan (60.75 ng/day). The cooking process may introduce more B[a]P(eq) into food, and the relative contribution of 16 PAHs in the diet would be changed during the cooking procedure.


Assuntos
Dieta/estatística & dados numéricos , Exposição Ambiental/análise , Análise de Alimentos , Hidrocarbonetos Policíclicos Aromáticos/análise , Adulto , China , Culinária , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Masculino , Neoplasias/induzido quimicamente , Hidrocarbonetos Policíclicos Aromáticos/efeitos adversos , Medição de Risco
14.
Environ Int ; 73: 158-66, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25124751

RESUMO

Lead exposure in the environment is a major hazard affecting human health, particularly for children. The blood lead levels in the local children living around the largest coking area in China were measured, and the source of blood lead and the main pathways of lead exposure were investigated based on lead isotopic ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) in blood and in a variety of media, including food, airborne particulate matter, soil, dust and drinking water. The children's blood lead level was 5.25 (1.59 to 34.36 as range) µg dL(-1), lower than the threshold in the current criteria of China defined by the US Centers for Disease Control (10 µg dL(-1)). The isotopic ratios in the blood were 2.111±0.018 for (208)Pb/(206)Pb and 0.864±0.005 for (207)Pb/(206)Pb, similar to those of vegetables, wheat, drinking water, airborne particulate matter, but different from those of vehicle emission and soil/dust, suggesting that the formers were the main pathway of lead exposure among the children. The exposure pathway analysis based on the isotopic ratios and the human health risk assessment showed that dietary intake of food and drinking water contributed 93.67% of total exposed lead. The study further indicated that the coal used in the coking plant is the dominant pollution source of lead in children's blood.


Assuntos
Coque , Poluentes Ambientais/sangue , Chumbo/sangue , Criança , China , Carvão Mineral/análise , Poluentes Ambientais/análise , Poluição Ambiental , Feminino , Humanos , Isótopos/análise , Isótopos/sangue , Chumbo/análise , Masculino
15.
Huan Jing Ke Xue ; 35(4): 1238-44, 2014 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-24946570

RESUMO

To investigate the sources and health risk of heavy metals in ambient air PM10 from the coking plant, the PM10 in the air around one coking plant was collected in June 2012. Then the heavy metals concentrations in PM10 were tested by the microwave-ICP-MS method. Furthermore, the USEPA's human exposure assessment model was applied to preliminarily evaluate the human health risks of the heavy metals in air particulate matter. The results show that the concentrations of 10 kinds of heavy metals in PM10 from the coking plant vary significantly, ranging from 3.06 x 10(-5) mg x m(-3) to 1.77 x 10(-2) mg x m(-3), of which the concentration of Cr is the highest, while the concentration of Co is the lowest, and the concentration of the carcinogenic substances is higher than that of the non-carcinogenic substances. The coking plant is identified to be the major source of the heavy metals in ambient air PM10, and Ni is the main polluting heavy metal. Moreover, the heavy risk assessment results reveal that the carcinogenic risks for adults are higher than children, while the carcinogenic risks in industrial areas and school relatively large. The non-carcinogenic risks for children are the highest in all the population, and the non-carcinogenic risks in residential area can not be ignored. Among the carcinogenic substances, the potential carcinogenic risks of Cd, Cr and As are comparatively large, Ni and Co have certain potential risks. Whereas, among the non-carcinogenic substances, the non-carcinogenic risks of Mn is great. Consequently, relevant departments should pay close attention to this situation.


Assuntos
Poluentes Atmosféricos/análise , Coque , Metais Pesados/análise , Material Particulado/análise , Adulto , Criança , Humanos , Indústrias , Medição de Risco
16.
J Colloid Interface Sci ; 415: 117-26, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24267338

RESUMO

Ionic liquid (1-butyl-2,3-dimethylimidazolium acetate, [BMMIm]OAc)-Pluronic P123 mixed micelle stabilized water-soluble Ni nanoparticles were characterized by UV-vis, XRD, XPS and TEM and then employed for catalytic hydrogenation. It was demonstrated that the mixed-micelle stabilized Ni NPs showed excellent catalytic performance for the selective hydrogenation of CC and nitro compounds in the aqueous phase under very mild reaction conditions, and also the Ni NPs catalysts can be recycled at least for eight times without significant decrease in catalytic activity. The results of characterization revealed that the mixed micelle-stabilized Ni NPs catalysts were highly dispersed in aqueous phases even after five catalytic recycles. In addition, adding ionic liquid ([BMMIm]OAc) can affect the micelle structure of P123 solutions and thus afford an additional steric protection from aggregation of Ni NPs, resulting in enhancing stability and catalytic activity of Ni NPs.


Assuntos
Imidazóis/química , Líquidos Iônicos/química , Nanopartículas Metálicas/química , Níquel/química , Poloxaleno/química , Alcenos/química , Catálise , Reutilização de Equipamento , Hidrogenação , Nanopartículas Metálicas/ultraestrutura , Micelas , Microscopia Eletrônica de Transmissão , Nitrocompostos/química , Espectroscopia Fotoeletrônica , Água/química
17.
Sci Total Environ ; 472: 1001-9, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24345860

RESUMO

Coking influences environmental quality and poses high risks to human health as large amounts of heavy metals and metalloids are emitted into the environment from coal during the coking process. Health risks depend heavily on multi-pathway and element-specific exposures, which have, unfortunately, been rarely studied. In this study, children's health risks and exposure levels to As, Se, and heavy metals (Pb, Cd, Cr, Ni, Co, Zn, Cu, Mn, V and Sb) in the water, soil, dust, air and locally produced food were studied based on field sampling and questionnaire-based surveys around the largest coking area in China. Human blood samples were collected and analyzed to indicate the exposure levels. The non-carcinogenic risks to children mainly resulted from Cr, Mn, Pb, As and Sb, the levels of which were 3 to 10 times higher than the acceptable levels (1.0×10(-6)). The carcinogenic risks to children were 30 to 200 times higher than the safe level (1.0×10(-6)-1.0×10(-4)), which could be attributed to Cr, As and Ni pollution. The estimated risks mainly came from the pathway involving the ingestion of locally produced food, accounting for more than 85% in total for most elements. For As, the food ingestion and air inhalation exposure pathways both contributed approximately 50%, respectively. The high risks in this study highlight the attention paid to the health of children who live in the vicinity of coking activities and the importance of site-specific multi-pathway health risk assessments and food safety to protect potentially exposed children.


Assuntos
Coque , Exposição Ambiental/análise , Poluentes Ambientais/análise , Poluição Ambiental/análise , Metais Pesados/análise , Arsênico/análise , Criança , China , Poeira/análise , Exposição Ambiental/estatística & dados numéricos , Poluição Ambiental/estatística & dados numéricos , Feminino , Humanos , Chumbo/análise , Masculino , Medição de Risco , Selênio/análise , Solo/química
18.
Chemistry ; 19(6): 2059-66, 2013 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-23255466

RESUMO

The use of transition-metal nanoparticles/ionic liquid (IL) as a thermoregulated and recyclable catalytic system for hydrogenation has been investigated under mild conditions. The functionalized ionic liquid was composed of poly(ethylene glycol)-functionalized alkylimidazolium as the cation and tris(meta-sulfonatophenyl)phosphine ([P(C(6)H(4)-m-SO(3))(3)](3-)) as the anion. Ethyl acetate was chosen as the thermomorphic solvent to avoid the use of toxic organic solvents. Due to a cooperative effect regulated by both the cation and anion of the ionic liquid, the nanocatalysts displayed distinguished temperature-dependent phase behavior and excellent catalytic activity and selectivity, coupled with high stability. In the hydrogenation of α,ß-unsaturated aldehydes, the ionic-liquid-stabilized palladium and rhodium nanoparticles exhibited higher selectivity for the hydrogenation of the C=C bonds than commercially available catalysts (Pd/C and Rh/C). We believe that the anion of the ionic liquid, [P(C(6)H(4)-m-SO(3))(3)](3-), plays a role in changing the surrounding electronic characteristics of the nanoparticles through its coordination capacity, whereas the poly(ethylene glycol)-functionalized alkylimidazolium cation is responsible for the thermomorphic properties of the nanocatalyst in ethyl acetate. The present catalytic systems can be employed for the hydrogenation of a wide range of substrates bearing different functional groups. The catalysts could be easily separated from the products by thermoregulated phase separation and efficiently recycled ten times without significant changes in their catalytic activity.

19.
Chem Asian J ; 5(5): 1178-84, 2010 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-20340156

RESUMO

Nickel nanoparticles (NPs) well-dispersed in the aqueous phase were conveniently prepared by reducing nickel(II) salt with hydrazine in the presence of the functionalized ionic liquid 1-(3-aminopropyl)-2,3-dimethylimidazolium bromide. UV/Vis spectroscopy, elemental analysis, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) show the presence of a weak interaction of the functionalized ionic liquid with Ni(II) and Ni(0) complexes. The face-centered cubic structure of the Ni(0) NPs was confirmed by X-ray diffraction (XRD) characterization. Transmission electron microscopy (TEM) images reveal that smaller Ni(0) particles of approximately 6-7 nm average diameter assemble to give larger, blackberry-shaped particles with an average diameter of around 35 nm. The Ni NPs were employed as highly efficient catalysts for the selective hydrogenation of C=C double bonds in the aqueous phase under mild reaction conditions (40-90 degrees C at 1.0-3.0 MPa), and the Ni(0) nanocatalysts in the aqueous phase are stable enough to be reused at least seven times without significant loss of catalytic activity during subsequent reuse cycles.

20.
Langmuir ; 26(4): 2505-13, 2010 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-20039597

RESUMO

The preparation, characterization, and catalytic properties of water-soluble palladium nanoparticles stabilized by the functionalized-poly(ethylene glycol) as a protective ligand were demonstrated for aerobic oxidation of alcohols in aqueous phase. UV/vis spectra and X-ray photoelectron spectroscopy (XPS) proved that there was an electronic interaction between the bidentate nitrogen ligand and palladium atoms. Transmission electron microscopy and XPS analysis showed that the particle size and surface properties of the generated palladium nanoparticles can be controlled by varying the amount of protective ligand and the kinds of reducing agents. It was found that both the size and surface properties of palladium nanoparticles played very important roles in affecting catalytic performance. The stabilized metallic palladium nanoparticles were proven to be the active centers for benzyl alcohol oxidation in the present system, and the water-soluble Pd nanocatalysts can also be extended to the selective oxidation of various alcohols.


Assuntos
Álcoois/química , Nanopartículas Metálicas/química , Paládio/química , Polietilenoglicóis/química , Água/química , Oxirredução , Tamanho da Partícula , Solubilidade , Propriedades de Superfície
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