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1.
JAMA ; 322(6): 546-556, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31408135

RESUMO

Importance: While air pollutants at historical levels have been associated with cardiovascular and respiratory diseases, it is not known whether exposure to contemporary air pollutant concentrations is associated with progression of emphysema. Objective: To assess the longitudinal association of ambient ozone (O3), fine particulate matter (PM2.5), oxides of nitrogen (NOx), and black carbon exposure with change in percent emphysema assessed via computed tomographic (CT) imaging and lung function. Design, Setting, and Participants: This cohort study included participants from the Multi-Ethnic Study of Atherosclerosis (MESA) Air and Lung Studies conducted in 6 metropolitan regions of the United States, which included 6814 adults aged 45 to 84 years recruited between July 2000 and August 2002, and an additional 257 participants recruited from February 2005 to May 2007, with follow-up through November 2018. Exposures: Residence-specific air pollutant concentrations (O3, PM2.5, NOx, and black carbon) were estimated by validated spatiotemporal models incorporating cohort-specific monitoring, determined from 1999 through the end of follow-up. Main Outcomes and Measures: Percent emphysema, defined as the percent of lung pixels less than -950 Hounsfield units, was assessed up to 5 times per participant via cardiac CT scan (2000-2007) and equivalent regions on lung CT scans (2010-2018). Spirometry was performed up to 3 times per participant (2004-2018). Results: Among 7071 study participants (mean [range] age at recruitment, 60 [45-84] years; 3330 [47.1%] were men), 5780 were assigned outdoor residential air pollution concentrations in the year of their baseline examination and during the follow-up period and had at least 1 follow-up CT scan, and 2772 had at least 1 follow-up spirometric assessment, over a median of 10 years. Median percent emphysema was 3% at baseline and increased a mean of 0.58 percentage points per 10 years. Mean ambient concentrations of PM2.5 and NOx, but not O3, decreased substantially during follow-up. Ambient concentrations of O3, PM2.5, NOx, and black carbon at study baseline were significantly associated with greater increases in percent emphysema per 10 years (O3: 0.13 per 3 parts per billion [95% CI, 0.03-0.24]; PM2.5: 0.11 per 2 µg/m3 [95% CI, 0.03-0.19]; NOx: 0.06 per 10 parts per billion [95% CI, 0.01-0.12]; black carbon: 0.10 per 0.2 µg/m3 [95% CI, 0.01-0.18]). Ambient O3 and NOx concentrations, but not PM2.5 concentrations, during follow-up were also significantly associated with greater increases in percent emphysema. Ambient O3 concentrations, but not other pollutants, at baseline and during follow-up were significantly associated with a greater decline in forced expiratory volume in 1 second per 10 years (baseline: 13.41 mL per 3 parts per billion [95% CI, 0.7-26.1]; follow-up: 18.15 mL per 3 parts per billion [95% CI, 1.59-34.71]). Conclusions and Relevance: In this cohort study conducted between 2000 and 2018 in 6 US metropolitan regions, long-term exposure to ambient air pollutants was significantly associated with increasing emphysema assessed quantitatively using CT imaging and lung function.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Pulmão/fisiologia , Enfisema Pulmonar , Idoso , Idoso de 80 Anos ou mais , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Carbono/efeitos adversos , Carbono/análise , Estudos de Coortes , Progressão da Doença , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Óxidos de Nitrogênio/efeitos adversos , Óxidos de Nitrogênio/análise , Ozônio/efeitos adversos , Ozônio/análise , Material Particulado/efeitos adversos , Material Particulado/análise , Enfisema Pulmonar/epidemiologia , Enfisema Pulmonar/fisiopatologia , Testes de Função Respiratória , Tomografia Computadorizada por Raios X , Estados Unidos/epidemiologia
2.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2447-2456, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418248

RESUMO

The static chamber-gas chromatography method was applied to observe CO2 fluxes across the water-air interface from different aquaculture systems, including four groups of mesocosms, i.e., blank control system (CK), monoculture system of Sebastes schlegelii (F), monoculture system of Chlamys farreri (B) and polyculture system of S. schlegelii and C. farreri (FB). Meanwhile, the physical, chemical and biological indices of the water were measured. The results showed that the group CK was a stable CO2 source, with the mean flux of 12.42 mg·m-2·h-1. The group B was a CO2 source during the early and middle periods of the experiment and a CO2 sink at the end of the experiment, with the mean flux during the experiment being 10.95 mg·m-2·h-1. The change trends of CO2 flux in the group F and FB were generally consistent, acting as CO2 sources in the early period and as CO2 sinks subsequently. The mean fluxes of those two groups during the expe-riment were -3.53 and -10.49 mg·m-2·h-1, respectively. Water pH was a good predictor for CO2 flux across the water-air interface according to the result of regression analysis, with pH value of 8.25 as the critical threshold between efflux and influx. The net primary production of water column was the main factor influencing the CO2 flux, indicating that phytoplankton might be the main internal force regulating the CO2 flux across the water-air interface. Our results indicated that C. farreri at present stocking density in the polyculture system could promote phytoplankton biomass as well as primary production and therefore enhance the CO2 sink function.


Assuntos
Poluentes Atmosféricos/análise , Aquicultura , Dióxido de Carbono/análise , Pectinidae , Animais , Metano , Água
3.
Medicine (Baltimore) ; 98(30): e16556, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31348278

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) may be 1 of etiologic factors responsible for congenital heart diseases (CHDs). Variations of the microsomal epoxide hydrolase (EPHX1) gene, as well as their possible interactions with PAHs exposure, may increase susceptibility to CHDs.This case-control study investigated the risk of CHDs in relation to the EPHX1 polymorphisms and assessed the interactions between these polymorphisms and PAHs exposure in 357 mothers of CHDs fetuses and 270 control mothers. Logistic regression models for the risk of CHDs were applied to determine the effect of genetic polymorphisms using additive, recessive, and dominant genetic models, as well as gene-exposure interactions. Multiple testing was adjusted by applying the false discovery rate (FDR).None of the maternal genetic polymorphisms of EPHX1 was associated with CHDs occurrence. Only the single nucleotide polymorphism rs1051740 was associated with an increased risk of right-sided obstructive malformations under the recessive model (adjusted odds ratio [aOR] = 1.852, 95% confidence interval [CI]: 1.065, 3.22) before FDR correction. A possible modifying effect of PAHs exposure on genetic polymorphisms of EPHX1 was found in susceptibility to CHDs, though no multiplicative-scale interactions between maternal exposure to PAHs and polymorphisms of EPHX1 gene were seento affect the risk of CHDs.The role of EPHX1 gene polymorphisms for CHDs need to be further evaluated, in particularly by interacting with PAHs exposure.


Assuntos
Poluentes Atmosféricos/toxicidade , Epóxido Hidrolases/genética , Cardiopatias Congênitas/genética , Exposição Materna/efeitos adversos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Adulto , Estudos de Casos e Controles , China , Feminino , Feto/metabolismo , Predisposição Genética para Doença/embriologia , Predisposição Genética para Doença/genética , Cardiopatias Congênitas/embriologia , Humanos , Modelos Logísticos , Mães , Razão de Chances , Polimorfismo de Nucleotídeo Único , Gravidez
5.
J Agric Food Chem ; 67(31): 8452-8458, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31294967

RESUMO

Insights into the environmental fates of nitrated polycyclic aromatic hydrocarbons (NPAHs) in edible vegetables are of great significance for better evaluating human exposure to NPAHs through the dietary pathway. In this work, a fluorescence quenching method using graphene quantum dots as a fluorescent probe was first applied for the in vivo determination of 9-nitroanthracene (9-NAnt) and 1-nitropyrene (1-NPyr) adsorbed on the leaf surfaces of living lettuce (Lactuca sativa L.) seedlings. Moreover, the photolysis kinetics and mechanisms of the two adsorbed NPAHs were discussed. The photodegradation kinetics followed the pseudo-first-order equation, and the photodegradation half-life of 1-NPyr (7.4 ± 0.2 h) was greater than that of 9-NAnt (2.3 ± 0.1 h). Anthraquinone and pyrenediones were identified to be the main photolytic products of 9-NAnt and 1-NPyr, respectively. Intramolecular rearrangement was the most reasonable mechanism for the NPAH photolysis. The photolysis-driven degradation exhibited a key role in scavenging NPAHs from the vegetable leaf, indicating the reduction of NPAH transportation in the food chain.


Assuntos
Alface/química , Nitratos/química , Folhas de Planta/química , Hidrocarbonetos Policíclicos Aromáticos/química , Poluentes Atmosféricos/química , Cinética , Alface/crescimento & desenvolvimento , Alface/efeitos da radiação , Fotólise/efeitos da radiação , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/efeitos da radiação , Plântula/química , Plântula/crescimento & desenvolvimento , Plântula/efeitos da radiação
6.
Ying Yong Sheng Tai Xue Bao ; 30(6): 1847-1853, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31257755

RESUMO

Ammonium salts, including ammonium nitrate, ammonium sulfate and ammonium hydrogen sulfate, are the main components of secondary inorganic aerosols and play an important role in the formation of haze events. The sources and transformation processes of atmospheric ammonium have received more and more attention. In this study, we modified the previous stable isotope analysis technique by improving the injection volume and adding a pH adjustment step, which gave a rapid and accurate measurement of ammonium nitrogen isotope ratio in atmospheric aerosol samples. Firstly, we added alkaline hypobromite to the extracted solution of the atmospheric aerosol filter samples (0.25 µg·mL-1 ammonium nitrogen in 4 mL) to oxidize ammonium (NH4+) to nitrite (NO2-). Then, after adjusting the pH, nitrite (NO2-) was reduced to nitrous oxide (N2O) by hydroxylamine hydrochloride under pH <0.3. Finally, nitrous oxide (N2O) was analyzed by Precon-GasBench-IRMS system to measure ammonium nitrogen isotope ratio. Our approach required low amount of NH4+ and avoided the use of highly toxic and explosive reagents. Meanwhile, the precision of our method could reach as high as 0.2‰ (n=10). This method could increase the NH4+ reduction efficiency to 100% at a condition of pH <0.3 and satisfy the demands of precision and accuracy for determination of ammonium nitrogen isotope in atmospheric aerosol samples. This method would help us better understand the sources, evolutions, chemical and deposition processes of atmospheric ammonium.


Assuntos
Poluentes Atmosféricos/análise , Compostos de Amônio/análise , Monitoramento Ambiental , Hidroxilamina/química , Isótopos de Nitrogênio/análise , Nitrogênio , Oxirredução , Sais
7.
J Environ Sci (China) ; 84: 80-96, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31284919

RESUMO

Central Plains region of China, represented by Henan Province, is facing serious air pollution problems. Vehicular exhaust emissions had adverse impacts on the atmospheric environment. The first comprehensive and novel vehicle emission inventory for Henan Province using vehicle kilometers traveled, localized emission factors, and activity data at city-level was developed. Furthermore, 3 km × 3 km gridded emission and temporal variations were determined by using localized information. Results show that the total emissions of sulfur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO), particular matter with aerodynamic diameter < 10 µm (PM10), aerodynamic diameter < 2.5 µm (PM2.5), volatile organic compounds (VOCs), VOCs-evaporation and ammonia in 2015 were 9.1, 533.4, 1190.7, 23.7, 21.6, 150.8, 31.5 and 10.4 Gg, respectively, and the emission intensities of the above pollutants were 0.05, 2.7, 6.0, 0.1, 0.1, 0.8, 0.2 and 0.05 g/km, respectively. Vehicles meeting the Primary China 1, China 3 and China 4 contributed 89.1%, 82.7%, 75.3%, 75.5%, 75.5%, 68.2%, 68.4% and 82.3% for SO2, NOx, CO, PM10, PM2.5, VOCs, VOCs-evaporation and ammonia emissions, respectively. Zhengzhou, Zhoukou, Nanyang, Luoyang, Shangqiu and Xinyang showed relatively higher emissions and contributed more than 50% of each pollutant. The spatial distribution indicated obvious characteristics of the road network, and high-level emission was concentrated in the downtown areas. Additionally, the ozone formation potential (OFP) based on the estimated speciated VOC emissions was 569.6 Gg in Henan Province. Aliphatic and aromatic hydrocarbons were the main species of VOCs, whereas olefins contributed the largest proportion of OFP, with 42.2%.


Assuntos
Poluentes Atmosféricos , Poluição Relacionada com o Tráfego/estatística & dados numéricos , Emissões de Veículos , China , Cidades/estatística & dados numéricos , Ozônio , Compostos Orgânicos Voláteis
8.
Pneumologie ; 73(7): 407-429, 2019 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-31291669

RESUMO

The third part of the DGP statement introduces the current body of knowledge on less studied health outcomes associated with exposure to ambient air pollution: the negative impact on metabolism leading to impaired glucose tolerance and diabetes as well as contribution to the development of neurodegenerative disorders and delayed cognitive function in children. Furthermore, prenatal exposure and adverse effects on mother and child are addressed. Finally, the currently discussed biological mechanisms underlying various health effects associated with exposure to air pollution are described.Differing, but often complementary biological mechanisms create the basis for the diverse health outcomes caused by air pollution. Oxidative stress and a subclinical inflammatory response in the lungs and on a systemic level ("low-grade systemic inflammation") are considered to be key mechanisms. They promote secondary alterations in the body, such as vascular or metabolic processes, and may also result in the currently studied epigenetic phenomena or neuroinflammation. In this context, the health significance of soluble particulate matter and the role of ultrafine particles translocated across biological membranes into blood vessel and transported via the circulation to secondary target organs, such as liver, brain or the fetus, are intensively discussed.Diabetes is one of the leading chronic diseases worldwide, with a prevalence of almost 14 % in Germany. Although lifestyle factors are the main causes, current evidence suggests that long-term exposure to air pollution may additionally increase the risk for type 2 diabetes. Supporting evidence for a causal role of air pollution is provided by studies addressing the regulation of the blood glucose levels in metabolically healthy participants, insulin sensitivity, or pregnancy-related diabetes. Experimental studies provide further support for plausible biological mechanisms. However, prospective studies are needed to gain more evidence, taking multiple lifestyle and environmental factors, such as green space and noise, and an improved individual exposure assessment into account.The aging population has an increased risk of neurodegenerative diseases. First studies point towards a contribution of chronic exposure to air pollution, specifically by particulate matter. Several studies report its association with decreased neurocognitive capacity or an increased prevalence of dementia or Alzheimer's disease in adults. However, the studies are inhomogeneous regarding design, exposure and outcome, leading to inconsistent results. With respect to the influence on neurocognitive development of children, first studies suggest an association between the level of air pollution, e. g. at school, and delayed cognitive development.Even though the evidence for the different biological endpoints during pregnancy is still heterogeneous, the studies generally point towards an adverse impact of air pollution on the maternal and fetal organisms. The strongest evidence exists for low birth weight, with small effect sizes of only some grams, and for a higher incidence of reduced birth weight (< 2500 g). An increased risk for gestational hypertension and preeclampsia underscores the possible impact of exposure to air pollution on the maternal organism. However, the current body of evidence does not yet allow a final conclusion on the influence of intrauterine exposure to air pollution regarding early childhood lung function and development of allergies, particularly in light of the fact that it is hard to distinguish in epidemiological studies between the effects of pre- and postnatal exposure.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Diabetes Mellitus Tipo 2/epidemiologia , Exposição Ambiental , Material Particulado/efeitos adversos , Resultado da Gravidez/epidemiologia , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Alemanha/epidemiologia , Humanos , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Estudos Prospectivos
10.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(6): 686-691, 2019 Jun 10.
Artigo em Chinês | MEDLINE | ID: mdl-31238620

RESUMO

Objective: To explore the short-term effects of ambient PM(2.5) on the outpatient visits of chronic obstructive pulmonary disease (COPD) in Ningbo city. Methods: Through the regional health information platform, number of daily COPD outpatients from the four general hospitals in Ningbo was gathered. Related data on meteorological and air pollution from 2014 to 2016 was also collected. Generalized additive model (GAM) of Possion regression was used to estimate the impact of PM(2.5) pollution on COPD outpatients and the lagging effects. Results: In cold (November- April) or warm seasons (May-October), an 10 µg/m(3) increase of PM(2.5) would result in the excessive number of COPD outpatients as 1.87% (95%CI: 0.98%-2.76%), 2.09% (95%CI: 1.11%-3.08%) and 2.56% (95%CI: 0.56%-4.59%), respectively. In terms of the short-term effects of PM(2.5) the strongest was seen in the days of warm season but without delay (P<0.05). The strongest effect appeared at day 4 in cold season and the effect was particularly significant seen in the over 65 year-old group or in the female population. After the introduction of PM(10), SO(2) and NO(2), the concentration of PM(2.5), did not show significant effect on the number of hospital visits due to COPD on the same day (P>0.05). The effect of COPD on the fourth day showed a slight change after the lagging, and the effect was statistically significant (P<0.05). Conclusion: The increase of PM(2.5) concentration in Ningbo was related to the increase of COPD outpatient numbers. Effective prevention measures should be taken to protect the vulnerable population and to reduce the risk of COPD.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Exposição Ambiental/efeitos adversos , Ambulatório Hospitalar/estatística & dados numéricos , Pacientes Ambulatoriais/estatística & dados numéricos , Material Particulado/efeitos adversos , Doença Pulmonar Obstrutiva Crônica/etiologia , Idoso , Poluição do Ar/estatística & dados numéricos , Assistência Ambulatorial , Exposição Ambiental/estatística & dados numéricos , Feminino , Humanos , Material Particulado/análise , Doença Pulmonar Obstrutiva Crônica/epidemiologia , População Urbana
11.
Nature ; 570(7760): 167-168, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31190015
12.
Sante Publique ; S1(HS): 153-161, 2019 May 13.
Artigo em Francês | MEDLINE | ID: mdl-31210476

RESUMO

The problems associated with air pollution and higher air temperatures in cities have been known for over a century, but so have the impacts of trees and forests on improving air quality and regulating air temperatures. Science has advanced our understanding on the various ways that trees affect air quality and temperatures. Trees affect air quality and consequently human health in both positive and negative ways by regulating air temperatures, altering the local microclimates, altering building energy use, removing air pollutants and emitting various chemicals. While the overall effect of trees and forests is an improvement in air quality, local scale forest designs near pollutant sources need to be considered as trees alter wind flow and can affect pollutant dispersion and local concentrations. Forests can limit pollution dispersion and increase local pollutant concentrations (e.g., along streets), but can also protect sites from pollutant emissions and have substantial impacts on lowering local pollution concentrations (e.g., in forest stands). By understanding how trees affect air quality and air temperatures, better landscape designs can be implemented to use trees and forests to improve human health.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Florestas , Saúde Pública , Árvores , Meio Ambiente , Humanos
13.
Environ Health Prev Med ; 24(1): 38, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31153356

RESUMO

OBJECTIVE: Few studies investigating associations between fine particulate air pollution and hemorrhagic stroke have considered subtypes. Additionally, less is known about the modification of such association by factors measured at the individual level. We aimed to investigate the risk of fatal intracerebral hemorrhage (ICH) incidence in case of PM2.5 (particles ≤ 2.5 µm in aerodynamic diameter) exposure. METHODS: Data on incidence of fatal ICH from 1 June 2012 to 31 May 2014 were extracted from the acute stroke mortality database in Shanghai Municipal Center for Disease Control and Prevention (SCDC). We used the time-stratified case-crossover approach to assess the association between daily concentrations of PM2.5 and fatal ICH incidence in Shanghai, China. RESULTS: A total of 5286 fatal ICH cases occurred during our study period. The averaged concentration of PM2.5 was 77.45 µg/m3. The incidence of fatal ICH was significantly associated with PM2.5 concentration. Substantial differences were observed among subjects with diabetes compared with those without; following the increase of PM2.5 in lag2, the OR (95% CI) for subjects with diabetes was 1.26 (1.09-1.46) versus 1.05 (0.98-1.12) for those without. We did not find evidence of effect modification by hypertension and cigarette smoking. CONCLUSIONS: Fatal ICH incidence was associated with PM2.5 exposure. Our results also suggested that diabetes may increase the risk for ICH incidence in relation to PM2.5.


Assuntos
Poluentes Atmosféricos/análise , Hemorragia Cerebral/mortalidade , Exposição Ambiental/estatística & dados numéricos , Material Particulado/análise , Acidente Vascular Cerebral/mortalidade , Causas de Morte , China/epidemiologia , Diabetes Mellitus/mortalidade , Feminino , Humanos , Incidência , Masculino , Tamanho da Partícula
14.
J Environ Sci (China) ; 83: 152-160, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221378

RESUMO

The structure of the boundary layer affects the evolution of ozone (O3), and research into this structure will provide important insights for understanding photochemical pollution. In this study, we conducted a one-month observation (from June 15 to July 14, 2016) of the boundary layer meteorological factors as well as O3 and its precursors in Luancheng County, Shijiazhuang (37°53'N, 114°38'E). Our research showed that photochemical pollution in Shijiazhuang is serious, and the mean hourly maximum and mean 8-hr maximum O3 concentrations are 97.9 ±â€¯26.1 and 84.4 ±â€¯22.4 ppbV, respectively. Meteorological factors play a significant role in the formation of O3. High temperatures and southeasterly winds lead to elevated O3 values, and at moderate relative humidity (40%-50%) and medium boundary layer heights (1200-1500 m), O3 production sensitivity occurred in the transitional region between volatile organic compounds (VOC) and nitrogen oxides (NOx) limitations, and the O3 concentration was the highest. The vertical profiles of O3 were also measured by a tethered balloon. The results showed that a large amount of O3 was stored in the residual layer, and the concentration was positively correlated with the O3 concentration measured the previous day. During the daytime of the following day, the contribution of O3 stored in the residual layer to the boundary layer reached 27% ±â€¯7% on average.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Ozônio/análise , Ozônio Estratosférico , China , Óxidos de Nitrogênio/análise , Compostos Orgânicos Voláteis/análise
15.
J Environ Sci (China) ; 83: 174-182, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221380

RESUMO

Climate change and anthropogenic activities are expected to impact the environmental behaviors and fates of persistent organic pollutants (POPs), however, quantitative studies on these combined factors are scarce. In this study, dichlorodiphenyltrichloroethane (DDTs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) were used as examples to identify how and when those factors may be related to the deposition of POPs in the sediment of Lake Chaohu, China, using generalized additive models (GAMs). Three historical trends of DDT, PAH, and PCB deposition were delineated in a dated sediment core encompassing ~100 years of historical record: a steady state or gradually increasing stage, a rapidly increasing stage, and a declining stage. The GAM results showed that aquatic total phosphorus (TP) concentrations and regional GDP (anthropogenic factors) were dominant contributors to POP accumulation rates in the lake sediment. The fitted relationships between air temperature and sedimentary DDT and PAH concentrations were linear and negative, while a positive linear relationship was found for PCBs, suggesting that Lake Chaohu may have become a net source for DDTs and PAHs, and a sink for PCBs, under a progressively warming climate.


Assuntos
Poluentes Atmosféricos/análise , Mudança Climática , Monitoramento Ambiental , China , DDT , Sedimentos Geológicos , Hidrocarbonetos Clorados/análise , Lagos , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise
16.
J Environ Sci (China) ; 83: 21-38, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221384

RESUMO

In-situ measurements of aerosol optical properties were conducted at Mt. Huang from September 23 to October 28, 2012. Low averages of 82.2, 10.9, and 14.1 Mm-1 for scattering coefficient (σsp, neph, 550), hemispheric backscattering coefficient (σhbsp, neph, 550), and absorption coefficient (σap, 550), respectively, were obtained. Atmospheric aging process resulted in the increase of σap, 550 but the decrease of the single scattering albedo (ω550) at constant aerosol concentration. However, the proportion of non-light-absorbing components (non-BCs) was getting higher during the aging process, resulting in the increase of aerosol diameter, which also contributed to relatively higher σsp, neph, 550 and ω550. Diurnal cycles of σsp, neph, 550 and σap, 550 with high values in the morning and low values in the afternoon were observed closely related to the development of the planetary boundary layer and the mountain-valley breeze. BC mixing state, represented by the volume fraction of externally mixed BC to total BC (r), was retrieved by using the modified Mie model. The results showed r reduced from about 70% to 50% when the externally mixed non-BCs were considered. The periodical change and different diurnal patterns of r were due to the atmospheric aging and different air sources under different synoptic systems. Local biomass burning emissions were also one of the influencing factors on r. Aerosol radiative forcing for different mixing state were evaluated by a "two-layer-single-wavelength" model, showing the cooling effect of aerosols weakened with BC mixing state changing from external to core-shell mixture.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Fuligem/análise , Aerossóis/análise , Atmosfera/química , China
17.
J Environ Sci (China) ; 83: 217-228, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221385

RESUMO

The impact of air masses motion on marine aerosol properties was investigated using an on-board single particle mass spectrometer (SPAMS) deployed for the determination of single particle size resolved chemical composition over Southeast China Sea. Two aerosol blooms (E1 and E2) were observed during the cruise. High average particle number count occurred in E1 (7320), followed by E2 (5850), which was more than 100-150 times of the average particle number count during normal periods. Particles were classified as four major sources, including continental source, shipping source, marine source, and transport source based on the mass spectral similarity. Transport source was identified as those particles with high particle number count occurred only during aerosol bloom period. Three sub-types of EC-Ca, OC-Ca, and Al-rich were classified as transport source. EC-Ca was the dominant particles of the transport source, accounting for more than 70% of the total particles in aerosol bloom events. A uni-modal size distribution in the size range of 0.1-2.0 µm was observed during normal period, while a bimodal distribution with a tiny mode (<0.3 µm) and a coarse mode between 0.4 and 0.6 µm was present during aerosol bloom. The variation of aerosol source is consistent with air masses back trajectories, for the reason that most of the long-range air trajectories are from the ocean, while short air trajectories originate in the continental regions, which means that air masses have a significant impact on the aerosol physical-chemical properties along their tracks.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Movimentos do Ar , Poluição do Ar/estatística & dados numéricos , Atmosfera/química , China , Material Particulado/análise
18.
J Environ Sci (China) ; 83: 64-72, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221388

RESUMO

To evaluate the potential benefits of biomass use for air pollution control, this paper identified and quantified the emissions of major reactive organic compounds anticipated from biomass-fired industrial boilers. Wood pellets (WP) and straw pellets (SP) were burned to determine the volatile organic compound emission profiles for each biomass-boiler combination. More than 100 types of volatile organic compounds (VOCs) were measured from the two biomass boilers. The measured VOC species included alkanes, alkenes and acetylenes, aromatics, halocarbons and carbonyls. A single coal-fired boiler (CB) was also studied to provide a basis for comparison. Biomass boiler 1 (BB1) emitted relatively high proportions of alkanes (28.9%-38.1% by mass) and alkenes and acetylenes (23.4%-40.8%), while biomass boiler 2 (BB2) emitted relatively high proportions of aromatics (27.9%-29.2%) and oxygenated VOCs (33.0%-44.8%). The total VOC (TVOC) emission factors from BB1 (128.59-146.16 mg/kg) were higher than those from BB2 (41.26-85.29 mg/kg). The total ozone formation potential (OFP) ranged from 6.26 to 81.75 mg/m3 with an average of 33.66 mg/m3 for the two biomass boilers. The total secondary organic aerosol potential (SOAP) ranged from 61.56 to 211.67 mg/m3 with an average of 142.27 mg/m3 for the two biomass boilers. The emission factors (EFs) of TVOCs from biomass boilers in this study were similar to those for industrial coal-fired boilers with the same thermal power. These data can supplement existing VOC emission factors for biomass combustion and thus enrich the VOC emission inventory.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Ozônio/análise , Compostos Orgânicos Voláteis/análise , China , Incineração , Indústrias
19.
J Environ Sci (China) ; 83: 8-20, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221390

RESUMO

With rapid economic growth and urbanization, the Yangtze River Delta (YRD) region in China has experienced serious air pollution challenges. In this study, we analyzed the air pollution characteristics and their relationship with emissions and meteorology in the YRD region during 2014-2016. In recent years, the concentrations of all air pollutants, except O3, decreased. Spatially, the PM2.5, PM10, SO2, and CO concentrations were higher in the northern YRD region, and NO2 and O3 were higher in the central YRD region. Based on the number of non-attainment days (i.e., days with air quality index greater than 100), PM2.5 was the largest contributor to air pollution in the YRD region, followed by O3, PM10, and NO2. However, particulate matter pollution has declined gradually, while O3 pollution worsened. Meteorological conditions mainly influenced day-to-day variations in pollutant concentrations. PM2.5 concentration was inversely related to wind speed, while O3 concentration was positively correlated with temperature and negatively correlated with relative humidity. The air quality improvement in recent years was mainly attributed to emission reductions. During 2014-2016, PM2.5, PM10, SO2, NOx, CO, NH3, and volatile organic compound (VOC) emissions in the YRD region were reduced by 26.3%, 29.2%, 32.4%, 8.1%, 15.9%, 4.5%, and 0.3%, respectively. Regional transport also contributed to the air pollution. During regional haze periods, pollutants from North China and East China aggravated the pollution in the YRD region. Our findings suggest that emission reduction and regional joint prevention and control helped to improve the air quality in the YRD region.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental , Conceitos Meteorológicos , China , Meteorologia , Ozônio , Material Particulado/análise , Rios , Estações do Ano , Temperatura Ambiente , Urbanização
20.
J Environ Sci (China) ; 83: 96-109, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221392

RESUMO

A field measurement campaign was carried out during the late winter and early spring of 2015 in Budapest, the capital of Hungary. The size distribution (SD) and optical absorption of carbonaceous particulate matter (CPM) was measured online using a Scanning Mobility Particle Sizer (SMPS), a 7λ-aethalometer and an inhouse developed 4λ-Photoacoustic Spectrometer. Based on the SD data, the measurement period could be classified into days with and without new particle formation events (normal days and nucleation days), although particular nucleation-like events were observed on normal days as well. Three characteristic size modes were observed with CMDs of circa 15, 25 and 110 nm that corresponded to the nucleation, traffic and heating modes. Based on the temporal behavior of these modes both types of days were divided into distinctive daily periods (heating hours, traffic hours and nucleation hours). The optical absorption spectra (OAC and AAE) also displayed the same part of day behavior to that of SD. That way this paper is among the first to assess the optical response of urban nucleation events. Due to the simultaneous measurement of OAC by the 7λ-aethalometer and a 4λ-Photoacoustic Spectrometer, OAC was measured overall at 11 wavelengths. That way aethalometer correction factors (f and C) were determined at all aethalometer wavelengths using in situ reference photoacoustic measurements. Correction factors were found to have both wavelength and time of the day variation. In the case of f, no clear trend could be observed, however, Cref values increased both as a function of wavelength.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/instrumentação , Material Particulado/análise , Aerossóis , Carbono , Monitoramento Ambiental/métodos , Hungria , Tamanho da Partícula , Estações do Ano
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