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1.
J Environ Sci (China) ; 147: 451-461, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003061

RESUMO

Ketoprofen (KET), as a non-steroidal anti-inflammatory drug frequently detected in aqueous environments, is a threat to human health due to its accumulation and low biodegradability, which requires the transformation and degradation of KET in aqueous environments. In this paper, the reaction process of ozone-initiated KET degradation in water was investigated using density functional theory (DFT) method at the M06-2X/6-311++g(3df,2p)//M06-2X/6-31+g(d,p) level. The detailed reaction path of KET ozonation is proposed. The thermodynamic results show that ozone-initiated KET degradation is feasible. Under ultraviolet irradiation, the reaction of ozone with water can also produce OH radicals (HO·) that can react with KET. The degradation reaction of KET caused by HO· was further studied. The kinetic calculation illustrates that the reaction rate (1.99 × 10-1 (mol/L)-1 sec-1) of KET ozonation is relatively slow, but the reaction rate of HO· reaction is relatively high, which can further improve the degradation efficiency. On this basis, the effects of pollutant concentration, ozone concentration, natural organic matter, and pH value on degradation efficiency under UV/O3 process were analyzed. The ozonolysis reaction of KET is not sensitive to pH and is basically unaffected. Finally, the toxicity prediction of oxidation compounds produced by degradation reaction indicates that most of the degradation products are harmless, and a few products containing benzene rings are still toxic and have to be concerned. This study serves as a theoretical basis for analyzing the migration and transformation process of anti-inflammatory compounds in the water environment.


Assuntos
Cetoprofeno , Ozônio , Poluentes Químicos da Água , Cetoprofeno/química , Ozônio/química , Poluentes Químicos da Água/química , Cinética , Anti-Inflamatórios não Esteroides/química , Modelos Químicos , Purificação da Água/métodos
2.
J Environ Sci (China) ; 147: 642-651, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003079

RESUMO

Nowadays, it is still a challenge to prepared high efficiency and low cost formaldehyde (HCHO) removal catalysts in order to tackle the long-living indoor air pollution. Herein, δ-MnO2 is successfully synthesized by a facile ozonation strategy, where Mn2+ is oxidized by ozone (O3) bubble in an alkaline solution. It presents one of the best catalytic properties with a low 100% conversion temperature of 85°C for 50 ppm of HCHO under a GHSV of 48,000 mL/(g·hr). As a comparison, more than 6 times far longer oxidation time is needed if O3 is replaced by O2. Characterizations show that ozonation process generates a different intermediate of tetragonal ß-HMnO2, which would favor the quick transformation into the final product δ-MnO2, as compared with the relatively more thermodynamically stable monoclinic γ-HMnO2 in the O2 process. Finally, HCHO is found to be decomposed into CO2 via formate, dioxymethylene and carbonate species as identified by room temperature in-situ diffuse reflectance infrared fourier transform spectroscopy. All these results show great potency of this facile ozonation routine for the highly active δ-MnO2 synthesis in order to remove the HCHO contamination.


Assuntos
Formaldeído , Compostos de Manganês , Óxidos , Ozônio , Ozônio/química , Compostos de Manganês/química , Formaldeído/química , Óxidos/química , Poluentes Atmosféricos/química , Oxirredução , Temperatura , Poluição do Ar em Ambientes Fechados/prevenção & controle , Catálise
3.
J Environ Sci (China) ; 148: 126-138, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095151

RESUMO

Severe ground-level ozone (O3) pollution over major Chinese cities has become one of the most challenging problems, which have deleterious effects on human health and the sustainability of society. This study explored the spatiotemporal distribution characteristics of ground-level O3 and its precursors based on conventional pollutant and meteorological monitoring data in Zhejiang Province from 2016 to 2021. Then, a high-performance convolutional neural network (CNN) model was established by expanding the moment and the concentration variations to general factors. Finally, the response mechanism of O3 to the variation with crucial influencing factors is explored by controlling variables and interpolating target variables. The results indicated that the annual average MDA8-90th concentrations in Zhejiang Province are higher in the northern and lower in the southern. When the wind direction (WD) ranges from east to southwest and the wind speed (WS) ranges between 2 and 3 m/sec, higher O3 concentration prone to occur. At different temperatures (T), the O3 concentration showed a trend of first increasing and subsequently decreasing with increasing NO2 concentration, peaks at the NO2 concentration around 0.02 mg/m3. The sensitivity of NO2 to O3 formation is not easily affected by temperature, barometric pressure and dew point temperature. Additionally, there is a minimum [Formula: see text] at each temperature when the NO2 concentration is 0.03 mg/m3, and this minimum [Formula: see text] decreases with increasing temperature. The study explores the response mechanism of O3 with the change of driving variables, which can provide a scientific foundation and methodological support for the targeted management of O3 pollution.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Cidades , Monitoramento Ambiental , Redes Neurais de Computação , Ozônio , Ozônio/análise , Poluentes Atmosféricos/análise , China , Poluição do Ar/estatística & dados numéricos , Análise Espaço-Temporal
4.
J Environ Sci (China) ; 148: 210-220, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095158

RESUMO

Heterogeneous oxidation by gas-phase oxidants is an important chemical transformation pathway of secondary organic aerosol (SOA) and plays an important role in controlling the abundance, properties, as well as climate and health impacts of aerosols. However, our knowledge on this heterogeneous chemistry remains inadequate. In this study, the heterogeneous oxidation of α-pinene ozonolysis SOA by hydroxyl (OH) radicals was investigated under both low and high relative humidity (RH) conditions, with an emphasis on the evolution of molecular composition of SOA and its RH dependence. It is found that the heterogeneous oxidation of SOA at an OH exposure level equivalent to 12 hr of atmospheric aging leads to particle mass loss of 60% at 25% RH and 95% at 90% RH. The heterogeneous oxidation strongly changes the molecular composition of SOA. The dimer-to-monomer signal ratios increase dramatically with rising OH exposure, in particular under high RH conditions, suggesting that aerosol water stimulates the reaction of monomers with OH radicals more than that of dimers. In addition, the typical SOA tracer compounds such as pinic acid, pinonic acid, hydroxy pinonic acid and dimer esters (e.g., C17H26O8 and C19H28O7) have lifetimes of several hours against heterogeneous OH oxidation under typical atmospheric conditions, which highlights the need for the consideration of their heterogeneous loss in the estimation of monoterpene SOA concentrations using tracer-based methods. Our study sheds lights on the heterogeneous oxidation chemistry of monoterpene SOA and would help to understand their evolution and impacts in the atmosphere.


Assuntos
Aerossóis , Poluentes Atmosféricos , Monoterpenos Bicíclicos , Umidade , Radical Hidroxila , Oxirredução , Aerossóis/química , Radical Hidroxila/química , Monoterpenos Bicíclicos/química , Poluentes Atmosféricos/química , Poluentes Atmosféricos/análise , Ozônio/química , Modelos Químicos , Atmosfera/química , Monoterpenos/química
5.
J Environ Sci (China) ; 148: 502-514, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095184

RESUMO

Objective weather classification methods have been extensively applied to identify dominant ozone-favorable synoptic weather patterns (SWPs), however, the consistency of different classification methods is rarely examined. In this study, we apply two widely-used objective methods, the self-organizing map (SOM) and K-means clustering analysis, to derive ozone-favorable SWPs at four Chinese megacities in 2015-2022. We find that the two algorithms are largely consistent in recognizing dominant ozone-favorable SWPs for four Chinese megacities. In the case of classifying six SWPs, the derived circulation fields are highly similar with a spatial correlation of 0.99 between the two methods, and the difference in the mean frequency of each SWP is less than 7%. The six dominant ozone-favorable SWPs in Guangzhou are all characterized by anomaly higher radiation and temperature, lower cloud cover, relative humidity, and wind speed, and stronger subsidence compared to climatology mean. We find that during 2015-2022, the occurrence of ozone-favorable SWPs days increases significantly at a rate of 3.2 day/year, faster than the increases in the ozone exceedance days (3.0 day/year). The interannual variability between the occurrence of ozone-favorable SWPs and ozone exceedance days are generally consistent with a temporal correlation coefficient of 0.6. In particular, the significant increase in ozone-favorable SWPs in 2022, especially the Subtropical High type which typically occurs in September, is consistent with a long-lasting ozone pollution episode in Guangzhou during September 2022. Our results thus reveal that enhanced frequency of ozone-favorable SWPs plays an important role in the observed 2015-2022 ozone increase in Guangzhou.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Ozônio , Tempo (Meteorologia) , Ozônio/análise , China , Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos
6.
J Environ Sci (China) ; 148: 529-540, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095186

RESUMO

Monolithic catalysts with excellent O3 catalytic decomposition performance were prepared by in situ loading of Co-doped KMn8O16 on the surface of nickel foam. The triple-layer structure with Co-doped KMn8O16/Ni6MnO8/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO4 to Co(NO3)2·6H2O precursors. Importantly, the formed Ni6MnO8 structure between KMn8O16 and nickel foam during in situ synthesis process effectively protected nickel foam from further etching, which significantly enhanced the reaction stability of catalyst. The optimum amount of Co doping in KMn8O16 was available when the molar ratio of Mn to Co species in the precursor solution was 2:1. And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity, thus creating outstanding O3 decomposition activity. The O3 conversion under dry conditions and relative humidity of 65%, 90% over a period of 5 hr was 100%, 94% and 80% with the space velocity of 28,000 hr-1, respectively. The in situ constructed Co-doped KMn8O16/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process, which provided an opportunity for the design of monolithic catalyst for O3 catalytic decomposition.


Assuntos
Compostos de Manganês , Níquel , Óxidos , Ozônio , Óxidos/química , Níquel/química , Compostos de Manganês/química , Ozônio/química , Catálise , Umidade , Cobalto/química , Modelos Químicos , Poluentes Atmosféricos/química
7.
J Environ Sci (China) ; 149: 35-45, 2025 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39181648

RESUMO

Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts. Here the α-MnO2 catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid. Besides the increases in surface area and lattice dislocation, the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies. The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions. The decomposition route is also proposed based on the DRIFTS and DFT calculations: ozone is facile to adsorb on the oxygen vacancy, and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O2, reducing the reaction energy barrier of O2 desorption.


Assuntos
Umidade , Compostos de Manganês , Óxidos , Ozônio , Ozônio/química , Óxidos/química , Compostos de Manganês/química , Catálise , Modelos Químicos
8.
J Environ Sci (China) ; 149: 314-329, 2025 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39181645

RESUMO

Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta (YRD) region and its meteorology-related and emission-related have not been systematically analyzed. In this study, by using 8-year-long (2015-2022) surface ozone observation data, we attempted to reveal the variation of multiple timescale components using the Kolmogorov-Zurbenko filter, and the effects of meteorology and emissions were quantitatively isolated using multiple linear regression with meteorological variables. The results showed that the short-term, seasonal, and long-term components accounted for daily maximum 8-hr average O3 (O3-8 hr) concentration, 46.4%, 45.9%, and 1.0%, respectively. The meteorological impacts account for an average of 71.8% of O3-8 hr, and the YRD's eastern and northern sections are meteorology-sensitive areas. Based on statistical analysis technology with empirical orthogonal function, the contribution of meteorology, local emission, and transport in the long-term component of O3-8 hr were 0.21%, 0.12%, and 0.6%, respectively. The spatiotemporal analysis indicated that a distinct decreasing spatial pattern could be observed from coastal cities towards the northwest, influenced by the monsoon and synoptic conditions. The central urban agglomeration north and south of the YRD was particularly susceptible to local pollution. Among the cities studied, Shanghai, Anqing, and Xuancheng, located at similar latitudes, were significantly impacted by atmospheric transmission-the contribution of Shanghai, the maximum accounting for 3.6%.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Ozônio , China , Ozônio/análise , Poluentes Atmosféricos/análise , Rios/química , Estações do Ano , Meteorologia , Poluição do Ar/estatística & dados numéricos , Poluição do Ar/análise
9.
J Environ Sci (China) ; 149: 419-430, 2025 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39181654

RESUMO

A novel system for measuring net photochemical ozone production rates in the atmosphere based on cavity ring-down spectroscopy (OPR-CRDS) was developed. The system consists of two chambers (a reaction chamber and a reference chamber) and a dual-channel Ox-CRDS detector. To minimize the wall loss of Ox in the chambers, the inner surfaces of both chambers are coated with Teflon film. The performance of the OPR-CRDS system was characterized. It was found that even though the photolysis frequency (J value) decreased by 10%, the decrease in the P(O3) caused by the ultraviolet-blocking film coating was less than 3%. The two chambers had a good consistency in the mean residence time and the measurement of NO2 and Ox under the condition of no sunlight. The detection limit of the OPR-CRDS was determined to be 0.20 ppbv/hr. To further verify the accuracy of the system, the direct measurement values of the OPR-CRDS system were compared with the calculation results based on radical (OH, HO2, and RO2) reactions, and a good correlation was obtained between the measured and calculated values. Finally, the developed instrument was applied to obtain the comprehensive field observations at an urban site in the Yangtze River Delta (China) for 40 days, the time series and change characteristics of the P(O3) were obtained directly, and the good environmental adaptability and stability of the OPR-CRDS system were demonstrated. It is expected that the new instrument will be beneficial to investigations of the relationship between P(O3) and its precursors.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Ozônio , Ozônio/análise , Monitoramento Ambiental/métodos , Monitoramento Ambiental/instrumentação , Poluentes Atmosféricos/análise , Análise Espectral/métodos , China , Atmosfera/química , Fotólise
10.
J Environ Sci (China) ; 149: 444-455, 2025 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39181656

RESUMO

Oxidation of organic amines (OAs) or aromatic hydrocarbons (AHs) produces carbonyls, which further react with OAs to form carbonyl-amine condensation products, threatening environmental quality and human health. However, there is still a lack of systematic understanding of the carbonyl-amine condensation reaction processes of OAs or between OAs and AHs, and subsequent environmental health impact. This work systematically investigated the carbonyl-amine condensation coupled ozonolysis kinetics, reaction mechanism, secondary organic aerosol (SOA) formation and cytotoxicity from the mixture of dipropylamine (DPA) and styrene (STY) by a combined method of product mass spectrometry identification, particle property analysis and cell exposure evaluation. The results from ozonolysis of DPA and STY mixture revealed that STY inhibited the ozonolysis of DPA to different degrees to accelerate its own decay rate. The barycenter of carbonyl-amine condensation reactions was shifted from inside of DPA to between DPA and STY, which accelerated STY ozonolysis, but slowed down DPA ozonolysis. For the first time, ozonolysis of DPA and STY mixture to complex carbonyl-amine condensation products through the reactions of DPA with its carbonyl products, DPA with STY's carbonyl products and DPA's bond breakage product with STY's carbonyl products was confirmed. These condensation products significantly contributed to the formation and growth of SOA. The SOA containing particulate carbonyl-amine condensation products showed definite cytotoxicity. These findings are helpful to deeply and comprehensively understand the transformation, fate and environmental health effects of mixed organics in atmospheric environment.


Assuntos
Aerossóis , Poluentes Atmosféricos , Aminas , Ozônio , Estireno , Ozônio/química , Aminas/química , Aminas/toxicidade , Cinética , Estireno/química , Estireno/toxicidade , Poluentes Atmosféricos/química , Poluentes Atmosféricos/toxicidade , Humanos , Oxirredução , Modelos Químicos
11.
J Environ Sci (China) ; 150: 218-229, 2025 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-39306397

RESUMO

Assessing the impact of anthropogenic volatile organic compounds (VOCs) on ozone (O3) formation is vital for the management of emission reduction and pollution control. Continuous measurement of O3 and the major precursors was conducted in a typical light industrial city in the YRD region from 1 May to 25 July in 2021. Alkanes were the most abundant VOC group, contributing to 55.0% of TVOCs concentration (56.43 ± 21.10 ppb). OVOCs, aromatics, halides, alkenes, and alkynes contributed 18.7%, 9.6%, 9.3%, 5.2% and 1.9%, respectively. The observational site shifted from a typical VOC control regime to a mixed regime from May to July, which can be explained by the significant increase of ROx production, resulting in the transition of environment from NOx saturation to radical saturation with respect to O3 production. The optimal O3 control strategy should be dynamically changed depending on the transition of control regime. Under NOx saturation condition, minimizing the proportion of NOx in reduction could lead to better achievement of O3 alleviation. Under mixed control regime, the cut percentage gets the top priority for the effectiveness of O3 control. Five VOCs sources were identified: temperature dependent source (28.1%), vehicular exhausts (19.9%), petrochemical industries (7.2%), solvent & gasoline usage (32.3%) and manufacturing industries (12.6%). The increase of temperature and radiation would enhance the evaporation related VOC emissions, resulting in the increase of VOC concentration and the change of ROx circulation. Our results highlight determination of the optimal control strategies for O3 pollution in a typical YRD industrial city.


Assuntos
Poluentes Atmosféricos , Ozônio , Temperatura , Compostos Orgânicos Voláteis , Ozônio/química , Compostos Orgânicos Voláteis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Poluição do Ar/prevenção & controle , Emissões de Veículos/análise
12.
J Environ Sci (China) ; 150: 277-287, 2025 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-39306403

RESUMO

As an important component of secondary aerosols, sulfate plays a crucial role in regulating atmospheric radiative balance and influencing the secondary formation of ozone (O3). In real atmosphere, atmospheric oxidants NO2 and O3 can promote the oxidation of SO2 to form sulfate (SO42-) through multiphase chemistry that occur at different time scales. Due to the combined impact of meteorology, pollution sources, atmospheric chemistry, etc., time-scale dependence of SO2-SO42- conversion makes the impact of NO2/O3 on it more complex. In this study, based on long-term time series (2013-2020) of air pollution variables from seven stations in Hong Kong, the Multifractal Detrended Cross-Correlation Analysis (MFDCCA) method has been employed to quantify the cross-correlations between SO2 and SO42- in real atmosphere at different time scales, for examining the time-scale dependence of SO2-SO42- conversion efficiency. Furthermore, the Pearson correlation analysis has been used to study the influence of NO2/O3 on SO2-SO42- conversion, and the regional and seasonal differences have been analyzed by considering factors such as meteorology, pollution sources, and regional transport. Changes in the main components of secondary aerosols are closely linked with the co-control of regional PM2.5 and O3. Therefore, the exploration of the impact of co-existing NO2/O3 gases on the secondary formation of sulfates in real atmosphere is significant.


Assuntos
Poluentes Atmosféricos , Atmosfera , Monitoramento Ambiental , Dióxido de Nitrogênio , Ozônio , Sulfatos , Ozônio/química , Sulfatos/química , Sulfatos/análise , Atmosfera/química , Poluentes Atmosféricos/análise , Dióxido de Nitrogênio/análise , Hong Kong , Aerossóis/análise , Poluição do Ar/estatística & dados numéricos , Dióxido de Enxofre/análise , Dióxido de Enxofre/química
13.
J Environ Sci (China) ; 150: 466-476, 2025 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-39306421

RESUMO

This study has employed the master chemical mechanism (MCM) to investigate the influence of the ozone oxidation pathways in the atmospheric formation of H2SO4 from short-chain olefins in industrialized areas. In-situ H2SO4 formation data were obtained using a high-resolution chemical ionization time-of-flight mass spectrometer, and the simulated H2SO4 concentrations calculated using updated parameters for the MCM model exhibited good agreement with observations. In the simulation analysis of different reaction pathways involved in H2SO4 formation, hydroxyl radicals were found to dominate H2SO4 production during the daytime, while olefin ozone oxidation contributed up to 65% of total H2SO4 production during the night-time. A sensitivity analysis of the H2SO4 production parameters has revealed a high sensitivity to changes in sulfur dioxide, and a relatively high sensitivity to olefins with fast ozonolysis reaction rates and bimolecular reaction rates of resulting stabilized Criegee Intermediates. A high relative humidity promotes daytime H2SO4 formation, but has an inhibiting effect during the night-time due to the different dominant reaction pathways.


Assuntos
Poluentes Atmosféricos , Alcenos , Oxirredução , Ozônio , Ácidos Sulfúricos , Ozônio/química , Alcenos/química , Ácidos Sulfúricos/química , Poluentes Atmosféricos/química , Atmosfera/química , Modelos Químicos , Dióxido de Enxofre/química , Monitoramento Ambiental
14.
J Environ Sci (China) ; 150: 556-570, 2025 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-39306429

RESUMO

Elucidating the mutual effects between the different volatile organic compounds (VOCs) is crucial for comprehending the formation mechanism of atmospheric secondary organic aerosols (SOA). Here, the mixed VOCs experiments of isoprene and Δ3-carene/ß-caryophyllene were carried out in the presence of O3 using an indoor smog chamber. The suppression effect of isoprene was recognized by the scanning mobility particle sizer spectrometer, online vacuum ultraviolet free electron laser (VUV-FEL) photoionization aerosol mass spectrometry, and quantum chemical calculations. The results indicate that the suppression effect of isoprene on the ozonolysis of Δ3-carene and ß-caryophyllene shows fluctuating and monotonous trends, respectively. The carbon content of the precursor could be the main factor for regulating the strength of the suppression effect. Plausible structures and formation mechanisms of several new products generated from the single VOC precursor and VOC-cross-reaction are proposed, which enrich the category of VOC oxidation products. Meanwhile, a new dimerization mechanism of the RO2 + R'O2 reaction is suggested, which offers an intriguing perspective on the gas phase formation process of particle phase accretion products. The present findings provide valuable insights into clarifying the pivotal roles played by isoprene in the interplay between different VOCs and understanding of SOA formation mechanisms of VOC mixtures, especially nearby the emission origins.


Assuntos
Aerossóis , Poluentes Atmosféricos , Butadienos , Hemiterpenos , Ozônio , Sesquiterpenos Policíclicos , Compostos Orgânicos Voláteis , Butadienos/química , Hemiterpenos/química , Ozônio/química , Sesquiterpenos Policíclicos/química , Poluentes Atmosféricos/química , Compostos Orgânicos Voláteis/química , Modelos Químicos , Dimerização
15.
J Environ Sci (China) ; 150: 692-703, 2025 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-39306440

RESUMO

Nitrogen oxides (NOx) are crucial in tropospheric photochemical ozone (O3) production and oxidation capacity. Currently, the widely used NOx measurement technique is chemiluminescence (CL) (CL-NOx), which tends to overestimate NO2 due to atmospheric oxidation products of NOx (i.e., NOz). We developed and characterized a NOx measurement system using the cavity attenuated phase shift (CAPS) technique (CAPS-NOx), which is free from interferences with nitrogen-containing species. The NOx measured by the CAPS-NOx and CL-NOx analyzers were compared. Results show that both analyzers showed consistent measurement results for NO, but the NO2 measured by the CAPS-NOx analyzer (NO2_CAPS) was mostly lower than that measured by the CL-NOx analyzer (NO2_CL), which led to the deviations in O3 formation sensitivity regime and Ox (= O3 + NO2) sources (i.e., regional background and photochemically produced Ox) determined by the ozone production efficiencies (OPE) calculated from NO2_CL and NO2_CAPS. Overall, OPE_CL exceeded OPE_CAPS by 18.9%, which shifted 3 out of 13 observation days from the VOCs-limited to the transition regime when judging using OPE_CL, as compared to calculations using OPE_CAPS. During the observation period, days dominated by regional background Ox accounted for 46% and 62% when determined using NO2_CL and NO2_CAPS, respectively. These findings suggest that the use of the CL-NOx analyzer tends to underestimate both the VOCs-limited regime and the regional background Ox dominated days. The newly built CAPS-NOx analyzer here can promote the accurate measurement of NO2, which is meaningful for diagnosing O3 formation regimes and Ox sources.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Óxidos de Nitrogênio , Ozônio , Óxidos de Nitrogênio/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Monitoramento Ambiental/instrumentação , Ozônio/análise , Atmosfera/química
16.
Glob Chang Biol ; 30(9): e17500, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39262235

RESUMO

The coincidence of rising ozone concentrations ([O3]), increasing global temperatures, and drought episodes is expected to become more intense and frequent in the future. A better understanding of the responses of crop yield to elevated [O3] under different levels of drought and high temperature stress is, therefore, critical for projecting future food production potential. Using a 15-year open-air field experiment in central Illinois, we assessed the impacts of elevated [O3] coupled with variation in growing season temperature and water availability on soybean seed yield. Thirteen soybean cultivars were exposed to a wide range of season-long elevated [O3] in the field using free-air O3 concentration enrichment. Elevated [O3] treatments reduced soybean seed yield from as little as 5.3% in 2005 to 35.2% in 2010. Although cultivars differed in yield response to elevated [O3] (R), ranging from 17.5% to -76.4%, there was a significant negative correlation between R and O3 dosage. Soybean cultivars showed greater seed yield losses to elevated [O3] when grown at drier or hotter conditions compared to wetter or cooler years, because the hotter and drier conditions were associated with greater O3 treatment. However, year-to-year variation in weather conditions did not influence the sensitivity of soybean seed yield to a given increase in [O3]. Collectively, this study quantitatively demonstrates that, although drought conditions or warmer temperatures led to greater O3 treatment concentrations and O3-induced seed yield reduction, drought and temperature stress did not alter soybean's sensitivity to O3. Our results have important implications for modeling the effects of rising O3 pollution on crops and suggest that altering irrigation practices to mitigate O3 stress may not be effective in reducing crop sensitivity to O3.


Assuntos
Secas , Glycine max , Temperatura Alta , Ozônio , Estações do Ano , Sementes , Glycine max/crescimento & desenvolvimento , Glycine max/fisiologia , Glycine max/metabolismo , Ozônio/análise , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Illinois
18.
Sci Rep ; 14(1): 21624, 2024 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-39285233

RESUMO

In India, the spatial coverage of air pollution data is not homogeneous due to the regionally restricted number of monitoring stations. In a such situation, utilising satellite data might greatly influence choices aimed at enhancing the environment. It is essential to estimate significant air contaminants, comprehend their health impacts, and anticipate air quality to safeguard public health from dangerous pollutants. The current study intends to investigate the spatial and temporal heterogeneity of important air pollutants, such as sulphur dioxide, nitrogen dioxide, carbon monoxide, and ozone, utilising Sentinel-5P TROPOMI satellite images. A comprehensive spatiotemporal analysis of air quality was conducted for the entire country with a special focus on five metro cities from 2019 to 2022, encompassing the pre-COVID-19, during-COVID-19, and current scenarios. Seasonal research revealed that air pollutant concentrations are highest in the winter, followed by the summer and monsoon, with the exception of ozone. Ozone had the greatest concentrations throughout the summer season. The analysis has revealed that NO2 hotspots are predominantly located in megacities, while SO2 hotspots are associated with industrial clusters. Delhi exhibits high levels of NO2 pollution, while Kolkata is highly affected by SO2 pollution compared to other major cities. Notably, there was an 11% increase in SO2 concentrations in Kolkata and a 20% increase in NO2 concentrations in Delhi from 2019 to 2022. The COVID-19 lockdown saw significant drops in NO2 concentrations in 2020; specifically, - 20% in Mumbai, - 18% in Delhi, - 14% in Kolkata, - 12% in Chennai, and - 15% in Hyderabad. This study provides valuable insights into the seasonal, monthly, and yearly behaviour of pollutants and offers a novel approach for hotspot analysis, aiding in the identification of major air pollution sources. The results offer valuable insights for developing effective strategies to tackle air pollution, safeguard public health, and improve the overall environmental quality in India. The study underscores the importance of satellite data analysis and presents a comprehensive assessment of the impact of the shutdown on air quality, laying the groundwork for evidence-based decision-making and long-term pollution mitigation efforts.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Cidades , Monitoramento Ambiental , Dióxido de Nitrogênio , Estações do Ano , Dióxido de Enxofre , COVID-19/epidemiologia , Humanos , Poluição do Ar/análise , Poluentes Atmosféricos/análise , Índia/epidemiologia , Dióxido de Enxofre/análise , Monitoramento Ambiental/métodos , Dióxido de Nitrogênio/análise , SARS-CoV-2/isolamento & purificação , Ozônio/análise , Análise Espaço-Temporal , Monóxido de Carbono/análise
19.
Environ Int ; 191: 108963, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39241332

RESUMO

BACKGROUND: There is increasing evidence that air pollution and noise may have detrimental psychological impacts, but there are few studies evaluating adolescents, ground-level ozone exposure, multi-exposure models, or metrics beyond outdoor residential exposure. This study aimed to address these gaps. METHODS: Annual air pollution and traffic noise exposure at home and school were modelled for adolescents in the Greater London SCAMP cohort (N=7555). Indoor, outdoor and hybrid environments were modelled for air pollution. Cognitive and mental health measures were self-completed at two timepoints (baseline aged 11-12 and follow-up aged 13-15). Associations were modelled using multi-level multivariate linear or ordinal logistic regression. RESULTS: This is the first study to investigate ground-level ozone exposure in relation to adolescent executive functioning, finding that a 1 interquartile range increase in outdoor ozone corresponded to -0.06 (p < 0.001) z-score between baseline and follow-up, 38 % less improvement than average (median development + 0.16). Exposure to nitrogen dioxide (NO2), 24-hour traffic noise, and particulate matter < 10 µg/m3 (PM10) were also significantly associated with slower executive functioning development when adjusting for ozone. In two-pollutant models, particulate matter and ozone were associated with increased externalising problems. Daytime and evening noise were associated with higher anxiety symptoms, and 24-hour noise with worse speech-in-noise perception (auditory processing). Adjusting for air pollutants, 24-hour noise was also associated with higher anxiety symptoms and slower fluid intelligence development. CONCLUSIONS: Ozone's potentially detrimental effects on adolescent cognition have been overlooked in the literature. Our findings also suggest harmful impacts of other air pollutants and noise on mental health. Further research should attempt to replicate these findings and use mechanistic enquiry to enhance causal inference. Policy makers should carefully consider how to manage the public health impacts of ozone, as efforts to reduce other air pollutants such as NO2 can increase ozone levels, as will the progression of climate change.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Cognição , Exposição Ambiental , Saúde Mental , Ozônio , Material Particulado , Humanos , Adolescente , Londres , Poluição do Ar/estatística & dados numéricos , Poluição do Ar/efeitos adversos , Masculino , Estudos Longitudinais , Feminino , Cognição/efeitos dos fármacos , Ozônio/análise , Material Particulado/análise , Criança , Poluentes Atmosféricos/análise , Ruído dos Transportes/efeitos adversos , Estudos de Coortes , Dióxido de Nitrogênio/análise , Ruído/efeitos adversos
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