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1.
J Environ Qual ; 49(5): 1141-1155, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016463

RESUMO

A critical step in determining soil-to-atmosphere nitrous oxide (N2 O) exchange using non-steady-state chambers is converting collected gas concentration versus time data to flux values using a flux calculation (FC) scheme. It is well documented that different FC schemes can produce different flux estimates for a given set of data. Available schemes differ in their theoretical basis, computational requirements, and performance in terms of both accuracy and precision. Nonlinear schemes tend to increase accuracy compared with linear regression but can also decrease precision. The chamber bias correction method can be used if soil physical data are available, but this introduces additional sources of error. Here, the essential theoretical and practical aspects of the most commonly used FC schemes are described as a basis for their selection and use. A gold standard approach for application and selection of FC schemes is presented, as well as alternative approaches based on availability of soil physical property data and intensity of sample collection during each chamber deployment. Additional criteria for scheme selection are provided in the form of an error analysis tool that quantifies performance with respect to both accuracy and precision based on chamber dimensions and sampling duration, soil properties, and analytical measurement precision. Example error analyses are presented for hypothetical conditions illustrating how such analysis can be used to guide FC scheme selection, estimate bias, and inform design of chambers and sampling regimes.


Assuntos
Óxido Nitroso/análise , Solo , Atmosfera
2.
Nature ; 585(7824): 225-233, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908268

RESUMO

Isoprene is the dominant non-methane organic compound emitted to the atmosphere1-3. It drives ozone and aerosol production, modulates atmospheric oxidation and interacts with the global nitrogen cycle4-8. Isoprene emissions are highly uncertain1,9, as is the nonlinear chemistry coupling isoprene and the hydroxyl radical, OH-its primary sink10-13. Here we present global isoprene measurements taken from space using the Cross-track Infrared Sounder. Together with observations of formaldehyde, an isoprene oxidation product, these measurements provide constraints on isoprene emissions and atmospheric oxidation. We find that the isoprene-formaldehyde relationships measured from space are broadly consistent with the current understanding of isoprene-OH chemistry, with no indication of missing OH recycling at low nitrogen oxide concentrations. We analyse these datasets over four global isoprene hotspots in relation to model predictions, and present a quantification of isoprene emissions based directly on satellite measurements of isoprene itself. A major discrepancy emerges over Amazonia, where current underestimates of natural nitrogen oxide emissions bias modelled OH and hence isoprene. Over southern Africa, we find that a prominent isoprene hotspot is missing from bottom-up predictions. A multi-year analysis sheds light on interannual isoprene variability, and suggests the influence of the El Niño/Southern Oscillation.


Assuntos
Atmosfera/química , Butadienos/análise , Butadienos/química , Mapeamento Geográfico , Hemiterpenos/análise , Hemiterpenos/química , Imagens de Satélites , África , Austrália , Brasil , Conjuntos de Dados como Assunto , El Niño Oscilação Sul , Formaldeído/química , Radical Hidroxila/análise , Radical Hidroxila/química , Ciclo do Nitrogênio , Óxidos de Nitrogênio/análise , Óxidos de Nitrogênio/química , Oxirredução , Estações do Ano , Sudeste dos Estados Unidos
3.
Chemosphere ; 254: 126867, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957282

RESUMO

The unique maneuverability, ease of deployment, simplicity in logistics, and relatively low costs of multicopters render them effective vehicles for low atmospheric research. While many efforts have contributed to the fundamental success of atmospheric applications of multicopters in the past, several challenges remain, including limited measurable variables, possible response-delay in real-time observations, insufficient measurement accuracy, endurance of harsh conditions and tolerance towards interferences. To address these challenges and further fortify the applicability in diversified research disciplines, this study developed an optimized multicopter UAV sounding technique (MUST). The MUST serves as an integrated platform by combining self-developed algorithms, optimized working environments for sensors/monitors, and retrofitted sampling devices to probe a comprehensive set of atmospheric variables. These variables of interest include meteorological parameters (temperature, relative humidity, pressure, wind direction and speed), the chemical composition (speciated VOCs, CO, CO2, CH4, CO2 isotopologues, O3, PM2.5, and black carbon), and the radiation flux, as well as visible and thermal images. The aim of this study is to achieve the following objectives: 1. to easily probe a comprehensive set of near-surface atmospheric variables; 2. to improve data quality by correcting for sensors' delay in real-time observations and minimizing environmental interferences; and 3. to enhance the versatility and applicability of aerial measurements by incorporating necessary hardware and software. Field launching cases from the surface to a maximum height of 1000 m were conducted to validate the robustness of the integrated MUST platform with sufficient speed, accuracy and resolution for the target variables.


Assuntos
Atmosfera/química , Monitoramento Ambiental/métodos , Conceitos Meteorológicos , Meteorologia , Vento
4.
Chemosphere ; 254: 126822, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957270

RESUMO

Atmosphere contamination management is one of the most important features in pollution risk management. The worldwide rise in tourism increases apprehension about its probable destructive conservation influence on various aspects of global conservation. One of the principal dangers increased by tourism-based modes of travel are nanoparticles (NPs) containing potentially hazardous elements (PHEs) contamination. One example of this is island destination of Lanzarote, in Spain's Canary Islands in which we examined contamination of the local atmosphere, water and soil. Important NPs containing PHEs, (e.g. arsenic, chromium, lead, and mercury), were found in this locale. It is reasonable to assume that this pollution poses an increased environmental danger to the local biome(s). Modes of transport (i.e. by car, airplane, bus) were shown to be an important contributor to this localized contamination as demonstrated by particulate matter (PM) readings collected near the island's airport. If no measures are taken to reduce vehicle and aircraft traffic, the tendency is to increase environmental degradation will continue unabated. As this particular area of Lanzarote is also one of wine production, increased pollution has the potential for negative impacts on the region's economy.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Nanopartículas/análise , Material Particulado/análise , Emissões de Veículos/análise , Aeronaves , Aeroportos , Atmosfera , Ecossistema , Poluição Ambiental , Geologia , Ilhas , Solo , Espanha
5.
J Environ Sci (China) ; 97: 180-185, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32933733

RESUMO

Novel brominated flame retardants (NBFRs) were investigated in Arctic air and soil samples collected from Ny-Ålesund and London Island, Svalbard, during Chinese scientific research expeditions to the Arctic during 2014-2015. The concentrations of Σ9NBFRs in the Arctic air and soil were 4.9-8.7 pg/m3 (average 6.8 pg/m3) and 101-201 pg/g dw (average 150 pg/g dw), respectively. The atmospheric concentration of hexabromobenzene (HBB) was significantly correlated with that of pentabromotoluene (PBT) and pentabromobenzene (PBBz), suggesting similar source and environmental fate in the Arctic air. No significant spatial difference was observed among the different sampling sites, both for air and soil samples, indicating that the effects of the scientific research stations on the occurrence of NBFRs in the Arctic were minor. The fugacities from soil to air of pentabromoethylbenzene (PBEB), 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE), and decabromodiphenylethane 1,2-bis (pentabromophenyl) ethane (DBDPE) were lower than the equilibrium value, indicating a nonequilibrium state of these compounds between air and soil, the dominant impact of deposition and the net transport from air to soil. The correlation analysis between the measured and predicted soil-atmosphere coefficients based on the absorption model showed that the impact of the soil organic matter on the distribution of NBFRs in the Arctic region was minor. To the best of our knowledge, this work is one of the limited reports on atmospheric NBFRs in the Arctic and the first study to investigate the occurrence and fate of NBFRs in the Arctic soil.


Assuntos
Retardadores de Chama/análise , Regiões Árticas , Atmosfera , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Ilhas , Londres , Solo , Svalbard
6.
Sci Total Environ ; 745: 141025, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32738691

RESUMO

Nitrous acid (HONO) is an important precursor of hydroxyl radical (OH) in the atmosphere. It is also toxic to human health. In this work, HONO concentrations were measured in Shijiazhuang using a Monitor for AeRosols and Gases in ambient Air (MARGA) from December 15, 2019 to March 15, 2020, which covered the heavy air pollution season, the Chinese New Year (CNY) vocation and the Corona Virus Disease-19 (COVID-19) lockdown period. During & after CNY overlapping COVID-19 lockdown, the air quality was significantly improved because of both the emission reduction and the increase in diffusion ability of air masses. The mean HONO concentration was 2.43 ± 1.08 ppbv before CNY, while it decreased to 1.53 ± 1.16 ppbv during CNY and 0.97 ± 0.76 ppbv after CNY. The lockdown during & after CNY reduced ~31% of ambient HONO along with ~62% of NO and ~36% of NO2 compared with those before CNY after the improvement of diffusion ability had been taken into consideration. Heterogeneous reaction of NO2 on ground surface dominated the nocturnal HONO sources, followed by heterogeneous reaction on aerosol surface, vehicle emission, reaction between NO and OH and emission from soil on pollution days throughout the observation. Except for elevated soil emission, other nighttime HONO sources and sinks decreased significantly during & after CNY. The relative importance of heterogeneous reaction of NO2 on surfaces further increased because of both the decrease in vehicle emission and the increase in the heterogeneous conversion kinetics from NO2 to HONO during & after CNY.


Assuntos
Poluição do Ar , Infecções por Coronavirus , Ácido Nitroso , Pandemias , Pneumonia Viral , Poluição do Ar/análise , Aniversários e Eventos Especiais , Atmosfera , Betacoronavirus , Radical Hidroxila
7.
Sci Total Environ ; 743: 140874, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758856

RESUMO

Atmospheric concentration of legacy (LFRs) and emerging flame retardants (EFRs) including 8 polybrominated diphenyl ethers (PBDEs), 6 novel brominated flame retardants (NBFRs), 2 dechlorane plus isomers (DP), and 8 chlorinated organophosphate flame retardants (OPFRs) were consecutively measured in eight major cities across Pakistan. A total of 96 samples (48 PM2.5 & 48 PUFs) were analyzed and the concentrations of ∑8PBDEs (gaseous+particulate) ranged between 40.8 and 288 pg/m3 with an average value of 172 pg/m3. ∑6NBFRs ranged between 12.0 and 35.0 pg/m3 with an average value of 22.5 pg/m3 while ∑8OPFRs ranged between 12,900-40,800 pg/m3 with an average of 24,700 pg/m3. Among the studied sites, Faisalabad city exhibited the higher concentrations of FRs among all cities which might be a consequence of textile mills and garment manufacturing industries. While analyzing the diurnal patterns, OPFRs depicted higher concentrations during night-time. The estimated risks of all groups of FRs from inhalation of ambient air were negligible for all the cities, according to USEPA guidelines. Nonetheless, our study is the first to report gaseous and particulate concentrations of FRs in air on a diurnal basis across major cities in Pakistan, offering insights into the atmospheric fate of these substances in urban areas in a sub-tropical region.


Assuntos
Retardadores de Chama/análise , Atmosfera , Cidades , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Humanos , Paquistão
8.
J Chromatogr A ; 1627: 461433, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823090

RESUMO

Atmospheric particulate matter (PM) is made up of suspended microscopic solid or liquid materials. It is derived from natural or anthropogenic sources. PM encompasses inhalable coarse particles, with aerodynamic diameters of between 2.5 µm and 10 µm, fine particles (<2.5 µm), and ultrafine (<0.1 µm) particles. In addition to being directly inhalable, causing harm, PM can also exert adverse effects on human wellbeing and the environment by its impact on precipitation and climate. Moreover, chemical contaminants may also be found adsorbed on PM, adding another dimension to the hazardous aspects of these materials. PM is normally collected on filters or impactors. PM-adsorbed contaminants need to be taken into solution before they can be extracted. This review focuses on a discussion of solvent-minimized sample preparation procedures, originally developed for aqueous samples, for the extraction and preconcentration of primarily organic contaminants from fine and coarse PM.


Assuntos
Poluentes Atmosféricos/análise , Atmosfera/química , Material Particulado/análise , Adsorção , Humanos , Miniaturização
9.
J Environ Radioact ; 222: 106383, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32861137

RESUMO

The determination procedure of low 137Cs concentrations in air using γ-spectrometry is essential wherever the net counts are smaller than the background of the spectrum. Such measurements have performed in April 2020 during the Chernobyl wildfires period. A significant event recorded in Thessaloniki's atmosphere during April 12, 2020, with 25.7 ± 0.7 µBq m-3 of 137Cs, was measured. Besides, a minor incident with a lower 137Cs concentration of 9.6 ± 0.8 µBq m-3 has occurred on April 21, 2020. The above results resemble to a previous one noticed during winter 2013, when signals up to 12.1 ± 0.8 µBq m-3 of 137Cs detected in the atmosphere, due to extensive use of 137Cs contaminated wood for residential heating. The results obtained demonstrate that no radiation hazard rose for the general public due to inhalation of the 137Cs in the air of Thessaloniki, Greece. Moreover, the residence time of the aerosol-bound 137Cs has estimated. The data presented are useful for basic simulation-inputs and comparison with global atmospheric models, which also discussed after comparison with the back trajectories predicted by the NOAA-HYSPLIT model.


Assuntos
Poluentes Radioativos do Ar , Radioisótopos de Césio , Acidente Nuclear de Chernobyl , Monitoramento de Radiação , Madeira , Poluentes Radioativos do Ar/análise , Atmosfera , Radioisótopos de Césio/análise , Florestas , Grécia , Madeira/química
10.
Nature ; 584(7820): 227-233, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32788734

RESUMO

Anthropogenic global surface warming is proportional to cumulative carbon emissions1-3; this relationship is partly determined by the uptake and storage of heat and carbon by the ocean4. The rates and patterns of ocean heat and carbon storage are influenced by ocean transport, such as mixing and large-scale circulation5-10. However, existing climate models do not accurately capture the observed patterns of ocean warming, with a large spread in their projections of ocean circulation and ocean heat uptake8,11. Additionally, assessing the influence of ocean circulation changes (specifically, the redistribution of heat by resolved advection) on patterns of observed and simulated ocean warming remains a challenge. Here we establish a linear relationship between the heat and carbon uptake of the ocean in response to anthropogenic emissions. This relationship is determined mainly by intrinsic parameters of the Earth system-namely, the ocean carbon buffer capacity, the radiative forcing of carbon dioxide and the carbon inventory of the ocean. We use this relationship to reveal the effect of changes in ocean circulation from carbon dioxide forcing on patterns of ocean warming in both observations and global Earth system models from the Fifth Coupled Model Intercomparison Project (CMIP5). We show that historical patterns of ocean warming are shaped by ocean heat redistribution, which CMIP5 models simulate poorly. However, we find that projected patterns of heat storage are primarily dictated by the pre-industrial ocean circulation (and small changes in unresolved ocean processes)-that is, by the patterns of added heat owing to ocean uptake of excess atmospheric heat rather than ocean warming by circulation changes. Climate models show more skill in simulating ocean heat storage by the pre-industrial circulation compared to heat redistribution, indicating that warming patterns of the ocean may become more predictable as the climate warms.


Assuntos
Dióxido de Carbono/análise , Aquecimento Global , Temperatura Alta , Oceanos e Mares , Água do Mar/análise , Água do Mar/química , Movimentos da Água , Atmosfera/química , Atividades Humanas
12.
Nat Commun ; 11(1): 4024, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788652

RESUMO

Soil microbial communities remain active during much of the Arctic winter, despite deeply frozen soils. Overwinter microbial activity affects the global carbon (C) budget, nutrient cycling, and vegetation composition. Microbial respiration is highly temperature sensitive in frozen soils, as liquid water and solute availability decrease rapidly with declining temperature. Climate warming and changes in snowpack are leading to warmer Arctic winter soils. Warmer winter soils are thought to yield greater microbial respiration of available C, greater overwinter CO2 efflux and greater nutrient availability to plants at thaw. Using field and laboratory observations and experiments, we demonstrate that persistently warm winter soils can lead to labile C starvation and reduced microbial respiration, despite the high C content of most Arctic soils. If winter soils continue to warm, microbial C limitation will reduce expected CO2 emissions and alter soil nutrient cycling, if not countered by greater labile C inputs.


Assuntos
Carbono , Microbiota/fisiologia , Estações do Ano , Microbiologia do Solo , Solo/química , Árvores/microbiologia , Alaska , Regiões Árticas , Atmosfera , Ciclo do Carbono , Dióxido de Carbono , Mudança Climática , Ecossistema , Glucose/metabolismo , Modelos Teóricos , Plantas , Temperatura
13.
Environ Sci Pollut Res Int ; 27(29): 36013-36026, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32816182

RESUMO

In the present work, wind tunnel experiments and numerical simulations were carried out to evaluate the physical behaviour of the fluid flow of a stockpile in the presence of an isolated cubic building. Comparing the obtained experimental results with those for the isolated stockpile configuration and observing the differences in the erosion patterns and emission estimates was possible to conclude that (i) the emissions considerably increase due to the presence of the building; (ii) the higher the free stream velocity, due to the presence of the obstacle, the more efficient the dynamics of the pavement process; and (iii) the increase of the gap between the building and the pile does not generate expressive changes in the emitted mass measurements. These findings play an important role since it is possible to obtain an optimal industrial open yard configuration where fewer particles are emitted to the atmosphere.


Assuntos
Poluentes Atmosféricos/análise , Modelos Teóricos , Atmosfera , Monitoramento Ambiental
14.
Int J Nanomedicine ; 15: 5813-5824, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32821103

RESUMO

Introduction: This paper presents a novel technique for the synthesis of graphene oxide (GO) with various surface features using high-density atmospheric plasma deposition. Furthermore, to investigate the use of hydrophobic, super-hydrophobic, and hydrophilic graphene in biological applications, we synthesized hydrophobic, super-hydrophobic, and hydrophilic graphene oxides by additional heat treatment and argon plasma treatment, respectively. In contrast to conventional fabrication procedures, reduced graphene oxide (rGO) formed under low pressure and high-temperature environment using a new synthesis method-developed and described in this study-offers a convenient deposition method on any kind surface with controlled wettability. Methods: High density at atmospheric plasma is used for the synthesis of rGO and GO and its biocompatibility based on various wetting properties was evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and the viability of cells in response to rGO and GO with various surface features was investigated. Structural integrity was characterized by Raman spectroscopy, FESEM and FE-TEM. Wettability was measured via contact angle method and confirmed with XPS analysis. Results: We found that GO coating with a hydrophilic feature is more biocompatible than other surfaces as observed in case of fibroblast cells. We have shown that wettability-controlled by GO deposition-influences biocompatibilities and antibacterial effect of biomaterial surfaces. Discussion: Measuring the contact angle, it is found that contact angle for hydrophobic is increased to 150.590 and reduced to 11.580 by heat and argon plasma treatment, respectively, from 75.880 that was initially in the case of hydrophobic surface. XPS analysis confirmed various oxygen-containing functional groups transforming as deposited hydrophobic surface into superhydrophobic and hydrophilic surface. Thus, we have proposed a new, direct, cost-effective, and highly productive method for the synthesis of rGO and GO-with various surface properties-for biological applications. Similarly, for the dental implant application, the Streptococcus mutans was used as an antibacterial effect and found that S. mutans grows slowly on hydrophilic surface. Thus, antibacterial effect was prominent on GO with hydrophilic surface.


Assuntos
Atmosfera/química , Grafite/síntese química , Gases em Plasma/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Grafite/química , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Oxirredução , Streptococcus mutans/efeitos dos fármacos , Água , Molhabilidade
15.
Environ Pollut ; 265(Pt A): 114956, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806399

RESUMO

Surface seawater and lower atmosphere gas samples were collected simultaneously between 18°N and 40°S in the open Pacific Ocean in 2006-2007. Samples were analyzed for organochlorine pesticides (OCPs) to assess their distribution patterns, the role of ocean in the long-range transport (LRT), and the air-water exchange directions in the open Pacific Ocean. Such open ocean studies can yield useful information such as establishing temporal and spatial trends and assessing primary vs secondary emissions of legacy OCPs. Target compounds included hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and its derivatives, and chlordane compounds. Concentrations for α-HCH, γ-HCH, trans-chlordane (TC), and cis-chlordane (CC) were higher in the Northern Hemisphere (NH) than the Southern Hemisphere (SH) in both gaseous and dissolved phases, while the distribution patterns of DDTs and heptachlor exo-epoxide (HEPX) showed a reversed pattern. In the N Pacific, concentrations of α-HCH and γ-HCH in the present work were lower by 63 and 16 times than those observed in 1989-1990. The distribution patterns of DDT suggested there was usage in the SH around 2006. Calculated fugacity ratios suggested that γ-HCH was volatilizing from surface water to the atmosphere, and the air-water exchange fluxes were 0.3-11.1 ng m-2 day-1. This is the first field study that reported the open Pacific Ocean has become the secondary source for γ-HCH and implied that ocean could affect LRT of OCPs by supplying these compounds via air-sea exchange.


Assuntos
Praguicidas/análise , Poluentes Químicos da Água/análise , Atmosfera , Monitoramento Ambiental , Oceano Pacífico , Água
16.
Environ Pollut ; 266(Pt 1): 115109, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32622216

RESUMO

Studies of the chemical composition of atmospheric aerosols, rain water and snow in various regions of the globe quite often show the presence of pyridine and a number of its low mass derivatives. Nevertheless, the sources of those compounds in the environment have not yet been established and definitely require elucidation, supported by reliable experimental results. In the present work the chemical composition of peat combustion products as one of the important sources of atmospheric aerosol emission is studied by two-dimensional gas chromatography - high-resolution mass spectrometry with a focus on the detection of pyridine derivatives. Twenty-five compounds of this class were reliably identified and quantified in laboratory experiments on peat burning. Among them 3-hydroxypyridine predominates, while the rest analytes are mostly represented by alkyl derivatives: pyridine, 2-methylpyridine, 3-methylpyridine, 2,5-dimethylpyridine, 2,6-dimethylpyridine, 2-ethylpyridine, lutidines (in order of decreasing concentration). The distribution of these combustion products coincides with that obtained earlier in environmental studies carried out in Arctic, Central Russia and France. The experiments on peat thermal decomposition by pyrolysis GC-MS demonstrated that the maximum concentrations as well as the number of detected analytes were found under conditions of oxygen lack and a temperature of about 500 °C, i.e. characteristic conditions of peat wildfires. The observed levels of pyridines' emission recalculated on the peat dry weight exceeded 200 mg kg-1. Considering hundreds of millions tons of peat burning in megafires over 20,000 tons of pyridines penetrate the Earth atmosphere annually. The obtained results allow concluding that peat burning may be the major and still underestimated source of pyridine and lower alkylpyridines in the Earth atmosphere.


Assuntos
Atmosfera , Solo , Aerossóis/análise , Regiões Árticas , Monitoramento Ambiental , França , Piridinas , Federação Russa
17.
BMC Infect Dis ; 20(1): 468, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32615923

RESUMO

BACKGROUND: Mumps is an acute respiratory infectious disease with obvious regional and seasonal differences. Exploring the impact of climate factors on the incidence of mumps and predicting its incidence trend on this basis could effectively control the outbreak and epidemic of mumps. METHODS: Considering the great differences of climate in the vast territory of China, this study divided the Chinese mainland into seven regions according to the administrative planning criteria, data of Mumps were collected from the China Disease Prevention and Control Information System, ARIMA model and ARIMAX model with meteorological factors were established to predict the incidence of mumps. RESULTS: In this study, we found that precipitation, air pressure, temperature, and wind speed had an impact on the incidence of mumps in most regions of China and the incidence of mumps in the north and southwest China was more susceptible to climate factors. Considering meteorological factors, the average relative error of ARIMAX model was 10.87%, which was lower than ARIMA model (15.57%). CONCLUSIONS: Meteorology factors were the important factors which can affect the incidence of mumps, ARIMAX model with meteorological factors could better simulate and predict the incidence of mumps in China, which has certain reference value for the prevention and control of mumps.


Assuntos
Atmosfera , Epidemias/prevenção & controle , Vírus da Caxumba , Caxumba/epidemiologia , Caxumba/prevenção & controle , Criança , Pré-Escolar , China/epidemiologia , Feminino , Previsões/métodos , Humanos , Incidência , Masculino , Modelos Teóricos , Caxumba/virologia , Prognóstico
18.
Bull Environ Contam Toxicol ; 105(1): 76-85, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32607623

RESUMO

Lake sediments, as an important emission source of nutrients and greenhouse gases, play a crucial role during the biogeochemical cycle processes. However, the impact mechanisms of different nutrient levels on greenhouse gas emission from lakes are still insufficient. In this study, the sediments from eight shallow lakes in the middle and lower reaches of the Yangtze River were cultured to study the release characteristics of greenhouse gases more than one month. Results showed that the greenhouse gases during the mineralization processes of sediments were mainly released to the atmosphere instead of being dissolved in the overlying water. The released concentrations of CH4 and CO2 were as high as 1 × 103 µmol L-1 in the later stage of the experiment, while the concentration of N2O was relatively low with a maximal value of about 10 µmol L-1. In addition, all the lake sediments displayed a nutrient release to the overlying water, where the concentrations of TC, TOC, TN, NH4+-N and TP were up to 173.0, 102.7, 36.7, 30.8 and 6.34 mg L-1, respectively. The nutrient levels of different lake sediments are symmetrical to the released nutrients concentrations in the overlying water. The further statistical analysis illustrated a synchronous nutrient controlled-release of greenhouse gases, that is, the higher the levels of nutrients in the sediments, the higher the concentrations of greenhouse gases released. These findings provide a better understanding that the control of endogenous nutrient levels of sediments is extremely important for lacustrine management, which can play a positive role in mitigating the greenhouse gas emissions from lake sediments.


Assuntos
Monitoramento Ambiental , Gases de Efeito Estufa , Poluentes Químicos da Água/análise , Atmosfera , China , Sedimentos Geológicos , Lagos/análise , Nutrientes , Fósforo/análise , Rios
19.
Bull Environ Contam Toxicol ; 105(1): 173-179, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32632464

RESUMO

In order to assess environmental exposure-associated human health risk of dioxin compounds for the population in the vicinity of a municipal solid waste incinerator (MSWI) in Shanghai, the atmospheric samples (n = 24) and soils samples (n = 96) were collected and analyzed to obtain the concentration level, pollution characteristics and seasonal changes of dioxin compounds in environmental medias. The toxicity equivalent concentration range of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was 30.9-409 fg WHO-TEQ·m-3 in atmosphere and 0.362-8.55 ng WHO-TEQ·kg-1 in soil. The non-carcinogenic health risk and carcinogenic health risk from PCDD/Fs environmental exposure of people living in the vicinity of the MSWI in Shanghai were all within the allowable range of the US Environmental Protection Agency, which implied that the MSWI in Shanghai did not produce additional risk for the population living in its vicinity.


Assuntos
Poluentes Atmosféricos/análise , Dioxinas/toxicidade , Exposição Ambiental , Incineração , Poluentes Atmosféricos/toxicidade , Atmosfera , China , Dibenzofuranos , Dibenzofuranos Policlorados/análise , Dioxinas/análise , Monitoramento Ambiental , Humanos , Dibenzodioxinas Policloradas/análise , Solo , Resíduos Sólidos/análise
20.
J Chromatogr A ; 1625: 461336, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709360

RESUMO

Thermal desorption aerosol gas chromatography mass spectrometry is capable of online measuring speciated organics in atmospheric aerosols. Compared to the one-dimensional gas chromatography, comprehensive two-dimensional gas chromatography increases the resolution and the sensitivity, mitigates the unresolved complex mixture and co-elution occurred in one-dimensional gas chromatography. In this study, we report a quartz filter-based thermal desorption aerosol comprehensive two-dimensional gas chromatography mass spectrometry (2D-Q-TAG). It combines a solid-state thermal modulator with a quartz filter-based thermal desorption aerosol gas chromatography mass spectrometry. The solid-state thermal modulator conducts modulation independently from the chromatographic oven without using cryogens or compressed air, which makes the system readily adaptive for field measurement. The 2D-Q-TAG was evaluated using C7-C40 n-alkanes and 16 polycyclic aromatic hydrocarbons (PAHs). It has low limits of detection from 0.001 to 0.104 ng. The instrument was then deployed to measure atmospheric PM2.5 (particulate matter with an equivalent aerodynamic diameter  ≤  2.5 µm) in urban Beijing. It allows in-situ detection of speciated organics in atmospheric aerosols with hourly time resolution. Organic classes including alkanes, furanones, alcohols, aldehydes, ketones, acids, PAHs, oxy-PAHs, and alkyl-naphthalenes were well separated and detected. The total mass concentration of n-alkanes ranged from 122.1 to 629.9 ng/m3. Diurnal variation of n-alkanes was captured due to the high time resolution of the instrument.


Assuntos
Aerossóis/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos/análise , Temperatura , Aerossóis/química , Alcanos/análise , Atmosfera/química , Limite de Detecção , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Padrões de Referência , Fatores de Tempo
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