Atmospheric emerging pollutants of cyclic volatile methyl siloxanes across the Yangtze River Delta region revealed by mobile measurements.

Cyclic volatile methyl siloxanes (cVMS) are a large class of high-production-volume chemicals that have garnered increasing scrutiny due to their potential adverse effects on air quality and human health. Among cVMS, octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) dominate global production, with China playing a pivotal role in their manufacture and consumption. Despite their widespread use, the atmospheric occurrence and sources of these compounds in China, even in the Yangtze River Delta (YRD)-the nation's most densely populated and economically developed region-remain largely unknown.

Exploring Aerosol Vertical Distributions and Their Influencing Factors: Insight from MAX-DOAS and Machine Learning.

Understanding aerosol vertical distribution is crucial for aerosol pollution mitigation but is hindered by limited observational data. This study employed multiaxis differential optical absorption spectroscopy (MAX-DOAS) technology with a coupled radiative transfer model-machine learning (RTM-ML) framework to retrieve high-resolution aerosol optical properties in Shanghai. Retrievals indicated vertically decreasing aerosols, peaking in the upper atmosphere in the summer and in the lower atmosphere in the winter.

Reactive Organic Gases from Vehicle Evaporative Emissions: Rates, Compositions, and Temperature Effects.

This study quantifies evaporative volatile organic compound emissions from China 3 to China 6 standard vehicles using a variable temperature sealed housing evaporative determination system. Total hydrocarbon (THC) emission factors during diurnal breathing losses (DBL) exhibited distinct temporal trends: the averages were 0.58, 0.

Photochemical impacts of atmospheric carbonyl compounds on ozone formation and radical chemistry in urban Shanghai.

Carbonyl compounds have been recognized as important precursors for photochemical ozone (O) and secondary organic aerosols; however, their quantitative contributions to urban photochemistry remain poorly constrained due to limited field measurements and chemical speciation. This study measured 47 atmospheric carbonyl compounds at an urban site in Shanghai during the summer of 2021 using a newly developed ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) method. The total carbonyl concentrations varied from 1.

HCHO and NO profile characteristics under different synoptic patterns in Shanghai, China.

Large-scale synoptic patterns significantly affect meteorological conditions and air pollution, yet their impacts on the vertical distribution of formaldehyde (HCHO) and nitrogen dioxide (NO) have been little studied. From 1 June 2020 to 31 December 2021, Multi-AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS) was used to observe NO and HCHO vertical profiles in three typical environments of Shanghai, China, representing urban, suburban and coastal rural environments, respectively. HCHO level is the highest at suburban site, NO is the highest at urban site.

Characteristics of atmospheric reduced-sulfur compounds at a suburban site of Shanghai.

Atmospheric dimethyl sulfide (DMS, CHSCH) and methanethiol (MeSH, CHSH) have been widely studied and recognized to significantly constrain the atmospheric sulfur budget. Nevertheless, while the role of DMS and MeSH remains largely uncertain in inland regions, learning about dimethyl disulfide (DMDS, CHSSCH) is also limited. In this study, we measured atmospheric DMS, MeSH and DMDS in winter, from 19 December 2022 to 30 January 2023, and spring, from 24 April to 2 June 2023 with a Vocus proton-transfer-reaction time-of-flight mass spectrometer (Vocus PTR-TOF) at the Dianshan Lake (DSL) Air Quality Monitoring Supersite in a suburban area of Shanghai, China.

N-doped carbon quantum dots-BiOBr composites: A case of van der Waals heterojunctions for efficient photocatalytic removal of NO under visible light irradiation.

The construction of van der Waals (VDW) heterojunctions has been deemed as an effective manner to boost photocatalytic performance since the presence of weak VDW force instead of strong chemical bonds ensures structural flexibility with diminished stress and defects caused by lattice mismatch. For such, a series of VDW heterojunctions were fabricated by decorating 2D BiOBr with 0D N-CQDs and comprehensively characterized. Accordingly, the successful establishment of 0D-2D N-CQDs-BiOBr (CD-BOB) VDW heterojunction composites was confirmed.

A robust black carbon prediction model derived from observational datasets in the Yangtze River Delta region, China.

Black carbon (BC) is a short-lived pollutant with significant environment and human health impacts. Monitoring BC is important, but its spatial coverage is limited. Therefore, predicting BC concentration is crucial in densely populated regions like the Yangtze River Delta (YRD).

Environmental and health impacts of reduced PM and trace metals from ship emissions under low-sulfur fuel oil policy in Shanghai, China.

Ship emissions can significantly exacerbate air pollution in coastal cities, threatening public health; however, a low-sulfur fuel oil policy, which restricts sulfur content in marine fuels, can effectively mitigate such pollution-driven challenges. This study employed a high-resolution ship emission inventory to assess the impacts of the fuel oil switch on air quality and public health in Shanghai from 2017 to 2021. Results showed a 37.

Insight into VOCs source profiles by machine learning: Role of commonalities in synergistic pollution controls.

Under the trend of low-carbon and cost-reduction, achieving efficient control requires identifying the commonalities in volatile organic compounds (VOCs) source profiles and implementing collaborative emissions reduction strategies. This study focuses on the analysis of common pollution characteristics in chemical industrial clusters, examining the emission behaviors of VOCs from nearly 200 emission outlets across 14 industries. A total of 593 VOCs were identified, including 488 new species.

Volatile organic compounds in a typical petrochemical production area in Shanghai, China: Source profiles, human health and environmental impacts.

Volatile organic compounds (VOCs) emitted from industrial facilities include significant precursors to the formation of aerosols and ozone in urban areas, often affecting atmospheric environments and public health. By investigating the VOC emission profiles across nine petrochemical production units, the predominant component in VOC emission profiles was alkanes, followed by oxygenated VOCs, aromatics, halocarbons, and alkenes. Aldehydes were identified as major contributors to odorous pollution.

Occurrence, formation mechanism, and health risk of polycyclic aromatic hydrocarbons in barbecued food.

Polycyclic aromatic hydrocarbons (PAHs) show negative impacts on human health. Dietary intake is the predominant way for PAH exposure, of which barbecued food is a crucial contributor. This review aims to provide a comprehensive insight into the formation mechanism, influencing factors, mitigation strategies, and health risks of PAHs in barbecued food.

Ground ozone rise during the 2022 Shanghai lockdown caused by the unfavorable emission reduction ratio of nitrogen oxides and volatile organic compounds.

Ground-level ozone (O) pollution has shifted from a scientific issue to a key focus of governmental action in China. In recent years, the concentration of NO in Shanghai has shown a decreasing trend of 3.7% annually, but ozone concentrations have exhibited significant interannual variability, particularly with a noticeable increase in 2022.

Nitrate-Photolysis Shortens the Lifetimes of Brown Carbon Tracers from Biomass Burning.

Biomass burning is an important source of brown carbon (BrC) aerosols, which influence climate by affecting the Earth's radiative balance. However, the transformation pathways of BrC chromophores, especially in the presence of photochemically active species, such as nitrate, are not well understood. In this study, the nitrate-mediated aqueous-phase photooxidation of three typical BrC chromophores from biomass burning was investigated, including 4-nitrocatechol, 3-nitrosalicylic acid, and 3,4-dinitrophenol.

The 2023 report of the synergetic roadmap on carbon neutrality and clean air for China: Carbon reduction, pollution mitigation, greening, and growth.

The response to climate change and air pollution control demonstrates strong synergy across scientific mechanisms, targets, strategies, and governance systems. This report, based on a monitoring indicator system for coordinated governance of air pollution and climate change, employs an interdisciplinary approach combining natural and social sciences. It establishes 20 indicators across five key areas: air pollution and climate change, governance systems and practices, structural transformation and technologies, atmospheric components and emission reduction pathways, and health impacts and co-benefits.

Unraveling Reactive Nitrogen Emissions in Heavy-Duty Diesel Vehicles across Evolving Standards and Cheating Tactics.

Reactive nitrogen (Nr) emissions significantly affect air quality and the nitrogen cycle in ecosystems. Heavy-duty diesel vehicles (HDDVs), as major sources of these emissions, exhibit complex emission characteristics because of the combined effects of different driving conditions and aftertreatment technologies. This study first investigated the emission factors (EFs) of Nr species, including NO, NO, HONO, NO, and NH, from HDDVs under different emission standards (China IV/V/VI) and cheating strategies, with a particular focus on the impact of selective catalytic reduction (SCR) systems.

Variations of chloride depletion and its impacts on ozone formation: Case study of a coastal area in Shanghai.

Chlorine plays a critical role in atmospheric chemistry. Marine chloride depletion, as a significant source of atmospheric chlorine, impacts coastal acid deposition, atmospheric oxidizing capacity, and global climate. Based on continuous monitoring data of PM water soluble ions, criteria pollutants, and meteorological data at Chongming Dongtan supersite from 2019 to 2022, variations in chloride depletion and related impact factors were analyzed.

[Predictive Model for O in Shanghai Based on the KZ Filtering Technique and LSTM].

In this study, a Kolmogorov-Zurbenko （KZ） filter was proposed to decompose the original ozone （O） sequence to improve the accuracy of ozone long-term series prediction and select relevant meteorological features. Furthermore, the enhanced maximal minimal redundancy （mRMR） feature selection technique was combined with the support vector regression （SVR） approach to select the most illuminating meteorological features. Subsequently, from May to August 2023, during high ozone concentration periods, a long short-term memory network （LSTM） was utilized to assess and predict high ozone concentration periods at the monitoring stations of Jingan （urban area）, Pudong-Chuansha （suburban area）, and Dianshan Lake （suburban area） in Shanghai.

Spatiotemporal Analysis of Complex Emission Dynamics in Port Areas Using High-Density Air Sensor Network.

Cargo terminals, as pivotal hubs of mechanical activities, maritime shipping, and land transportation, are significant sources of air pollutants, exhibiting considerable spatiotemporal heterogeneity due to the complex and irregular nature of emissions. This study employed a high-density air sensor network with 17 sites across four functional zones in two Shanghai cargo terminals to monitor NO and NO concentrations with high spatiotemporal resolution post sensor data validation against regulatory monitoring stations. Notably, NO and NO concentrations within the terminal surged during the night, peaking at 06:00 h, likely due to local regulations on heavy-duty diesel trucks.

[Characteristics and Influence of Atmospheric VOCs in Ozone Formation Potential in Suburb of Shanghai During Summer].

To help promote ozone pollution control and understand the influence of atmospheric volatile organic compounds （VOCs） on O during the summer ozone pollution season, the analyses of variation characteristics and ozone formation potentials of VOCs during O pollution episodes were carried out based on the online monitoring data of VOCs and O, as well as the meteorological parameters in the suburban site of Shanghai. The impact of key meteorological factors and regional transport on O and VOCs was investigated. The results showed that the mean value of atmospheric （VOCs） during summer in the suburban area of Shanghai was （20.