Air pollution imposes significant health and ecological damages. However, previous studies targeted on air quality improvement, focused on one of the two impacts independently of the other and fail to consider both health and ecological losses. This study establishes a dynamic multicity and multisector modeling framework by integrating emission inventories, future mitigation pathways, response surface models, and monetization methods of health and ecological benefits. Taking the Yangtze River Delta (YRD) in China as a case, we quantify the integrated benefits of air pollution control and propose coordinated emission reduction strategies of multiple species aiming at maximizing integrated benefits. Results show that from 2013 to 2020, emission reductions lowered annual economic losses by 709.5 billion CNY, with ecological benefits accounting for nearly half of health benefits. NH3 and NOx reductions were found to be particularly effective in achieving integrated benefits nowadays, with an optimal reduction ratio of approximately 0.75 across the YRD, and stronger NH3 mitigation needed in northeastern regions. Carbon neutrality pathways combined with targeted NH3 and VOCs controls yield greater equity, especially benefiting less-developed areas. On-road vehicles and agriculture are identified as key sectors for achieving overall health and ecological benefits. These findings provide a replicable model for multipollutant, multiobjective air quality management in rapidly industrializing regions worldwide.

Achieving carbon neutrality and improving air quality are pivotal sustainability strategies for the Global South countries. However, their global climate impacts over a realistic timescale remain unclear. Here we evaluate the climate impacts of China's carbon neutrality and Beautiful China policies using a fully coupled Earth system model and updated future anthropogenic emission scenarios. We find that, for an unexpectedly long time through ~2070, China's air pollutant reductions can cause a large global surface warming (0.12 ± 0.09 K for 2050-2070) that almost offsets the cooling from concurrent CO2 emission reduction (0.16 ± 0.05 K for 2050-2070), compared to a business-as-usual scenario. This warming is mainly attributed to reduced SO2 and organic matter emissions. Moreover, combined air pollutants and CO2 declines create a striking hemispheric temperature change contrast, because of the stronger aerosol-induced heating in the Northern Hemisphere. Considering that most future air pollutant reductions represent synergistic effects of carbon neutrality policies, the associated inevitable warming effect over decades highlights the importance of exploring more aggressive policies including early carbon neutrality, methane reductions, and negative carbon emissions.

Vehicle emission is a major source of urban ultrafine particles (UFPs), yet measurement and emission control for UFP lags significantly behind that of other pollutants. The China VI emission standard, one of the strictest globally, introduced the nation’s first particle number (PN) limits. This study focused on real-world PN emissions in the capital city Beijing, which adopted China VI ahead of the national schedule in 2019. Based on long-term particle number size distribution measurements and online UFP composition analysis, a pronounced decline in emission rates of vehicle-attributed PN from 2019 to 2023 was found, resulting in decreases of 70

In valley cities, gaseous precursors emitted from near-source can rapidly deposit and give rise to localized acid rain. The presence of local slope changes and convective meteorology facilitates the convergence of pollutants, thereby reducing the likelihood of atmospheric SO2 and NOx being transported to other regions through atmospheric movement, while increasing their susceptibility to exacerbating the acid deposition process. In our study, a decade-long dataset of precipitation samples was collected and analyzed. Subsequently, emission scenarios were simulated using high-resolution nested domains in the meteorological field-driven source-directed CMAQ model generated by the WRF model. Our findings demonstrate that effective management of regional SO2 emissions plays a pivotal role in regulating precipitation pH. Two control scenarios (reduction and relocation) conducted an evaluation and comparison of these approaches. The source reduction scenario effectively ensures that annual average SO2 levels remain below the threshold of 24 mu g/m(3) by maintaining total industrial emissions below 2,561.62 tonnes. However, it is important to note that there are significant seasonal variations in industrial emission limits due to climate and precipitation. In the migration scenario (ignoring terrain), the environmental SO2 in the study area was significantly reduced by an average of 16 mu g/m(3). Compared with source abatement, the relocation of energy-intensive industries to regions characterized by lower relative humidity mitigates pollution impacts on mountainous cities and ensures long-term economic benefits. Under complex terrain and small range of special meteorological conditions, the influencing factors of air pollution process and how to implement effective control strategies deserve continuous attention.

CO2 methanation is an important route for carbon emission mitigation and renewable energy storage. However, insufficient CO2 activation and inefficient hydrogenation of surface intermediates at low temperatures remain major challenges. In this work, Ni/CeO2 catalysts with distinct metal-support interaction degrees were constructed by regulating the interfacial contact of Ni-Ce, aiming to enhance the low-temperature methanation performance. The results suggest that Ni/CeO2 with strengthened Ni-CeO2 interfacial interaction exhibits more oxygen-vacancy-related defect sites, improved reducibility, and favorable Ni dispersion. These interrelated features collectively facilitate CO2 adsorption/activation and intermediate conversion, thereby contributing to the enhanced low-temperature methanation performance. Specifically, the CO2 conversion reached ∼80% at 250 °C. In situ Raman spectroscopy suggested the dynamic evolution of oxygen-vacancy-related defect sites during the reaction, while in situ DRIFTS suggested that CO2 methanation may proceed through both the formate-mediated pathway and the CO* pathway. These findings suggest that tailoring the Ni-Ce interfacial interaction, together with the associated changes in oxygen vacancy related defects, reducibility, and Ni dispersion, may provide an effective approach to improving the low-temperature CO2 methanation performance of Ni-based catalysts.

Fine particulate matter (PM2.5) remains a leading environmental health risk, yet air pollution control policies typically assume equal toxicity across emission sources. Unravelling the unequal toxicities in global PM2.5 emissions can support more effective air pollution control. Here, we integrate cell-based toxicological profiles with global emission inventories to develop the first global dataset of toxicity-adjusted PM2.5 emissions. We show that global toxicity-adjusted emissions are dominated by residential solid-fuel combustion, and that hotspots of PM2.5 mass and toxicity diverge substantially, with the highest toxicities occurring largely in regions reliant on traditional biomass. Low-income countries exhibit disproportionately high toxicity-adjusted emissions relative to their energy use, revealing a strong global environmental inequity. Incorporating unequal toxicities reshapes emission-control priorities, shifting many countries from mass-dominated industrial or power sectors towards residential combustion. We propose a toxicity-informed framework for air pollution control, which is adaptable to diverse socioeconomic contexts and can enhance global health and sustainability.

The global shift from air quality attainment to mitigating the health impacts of air pollution, exemplified by the 2025 World Health Assembly’s goal to halve pollution-related deaths by 2040, demands a new generation of policy tools. However, existing frameworks remain rooted in static assessments of population vulnerability, despite rapid demographic shifts and socioeconomic transformations. Here, we introduce a Dynamic Response Surface Model (DRSM) that integrates time-varying age structures, nonlinear atmospheric chemistry, and interregional pollution transport into a unified decision architecture to formulate a health-oriented air pollution control strategy. Applying the DRSM to China, it reveals that current policies fail to curb rising health burdens in most provinces, despite ongoing reductions in anthropogenic emissions. Population vulnerability will increasingly offset the health returns of emission reductions and exacerbate inter-provincial inequities until approximately 2060. To halt the deterioration of air pollution-related mortality, annual national emission reduction of at least 2.7% for PM2.5 precursors and 5.8% for ozone precursors is required. A health-optimized mitigation pathway for 2035, shifting control priorities from traditional megacity clusters toward central China, demonstrates a highly favorable benefit-cost ratio. This strategic reallocation not only improves cost-effectiveness but also corrects long-standing spatial imbalances in environmental policy. The DRSM establishes a new paradigm for air quality governance that transcends ambient pollutant metrics, redefining policy success by its capacity to deliver cost-effective and equitable improvements in global health and longevity.

In recent years, the Earth has likely experienced an accelerated warming trend, raising growing interest in the possible contributing factors. From 2013 to 2023, global anthropogenic air pollutant emissions declined significantly and brought enormous public health benefits, but the contribution of reduced aerosol masking of greenhouse warming to recent trends remains uncertain. Using two state-of-the-art global climate models, we show that global air pollutant emission reductions during 2013-2023 caused a global effective radiative forcing of 0.16 W/m2 (90% CI: 0.13 to 0.20), with international shipping, China, and other land regions contributing 0.05 W/m2 (0.00 to 0.09), 0.07 W/m2 (0.03 to 0.11), and 0.05 W/m2 (0.00 to 0.09), respectively. International shipping contributes disproportionately to radiative forcing relative to its emission reductions, highlighting its high forcing efficiency. The combined forcings are estimated to have contributed a warming of 0.044 °C (0.012 to 0.076) over 2013-2023, accounting for 52% (14 to 90%) of the observed warming acceleration (0.084 °C/decade) relative to the 1970-2012 trend. Especially strong reductions in aerosol-cloud interactions are found over the North Pacific, driven primarily by the downwind impacts of East Asian emission reductions. Aerosol unmasking contributes to the recent acceleration of warming and highlights the importance of accurately quantifying air pollutant emission changes for future climate projections.

Improving household energy efficiency is the primary policy option for mitigating the rapid growth of energy consumption in the residential sector; however, the existence of the energy rebound effect poses a significant challenge to energy-saving policies aimed at improving energy efficiency. This study calculated the energy rebound effect for urban households in China using an improved stochastic frontier model with provincial panel data from 2005 to 2022. We then analysed the spatiotemporal dynamics of energy rebound and energy efficiency using kernel density analysis. Results show that the arithmetic mean energy efficiency of urban households in China increased from 0.608 in 2005 to 0.785 in 2022, while their energy consumption has shown a stable upward trend. Per capita disposable income and fuel prices have significant positive and negative effects, respectively, on the energy rebound effect of urban households. At the same time, the arithmetic mean of the energy rebound effect increased from 0.290 in 2005 to 0.932 in 2022, and provinces with higher energy efficiency always have a higher energy rebound effect. Based on the results, several measures are proposed to mitigate the energy rebound effect of urban households. First, efforts should be made to improve energy efficiency by boosting per capita disposable income or updating living infrastructure. Second, fuel price policies should be refined by linking fuel prices to the consumer price index for regular adjustments. Third, households should be actively guided towards low-carbon consumption behaviours by enhancing urban households’ recognition of low-carbon living and by creating an external environment that facilitates their adoption.

Converting CO2 to CH4 under mild conditions is a promising strategy for solving environmental and energy problems, but also a challenge. In this work, the low-temperature CO2 hydrogenation process over Ni/CeO2 catalysts was significantly accelerated by optimizing the H2 dissociation ability of Ni through the size effect, thus A-Ni/CeO2 with an average size of 4.9 nm achieved 83.4% CO2 conversion with similar to 100% CH4 selectivity even at 225 degrees C. Systematic H2/D2 isotopic exchange experiments, in situ spectroscopic characterizations, and density functional theory (DFT) calculations reveal that the enhanced H2 activation ability not only promoted the creation of oxygen vacancies and hydroxyl group favorable for CO2 adsorption/activation in the pre-reduction process, but also the simultaneous hydrogenation of reactive intermediates belonging to carbonyl and formate pathway into CH4 in the reaction process. This fundamental understanding of the H2 dissociation effect on CO2 activation and hydrogenation provides critical insights for designing catalysts with considerable low-temperature activity, which significantly reduces energy consumption and operating costs for industrial CO2 conversion. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)Ni(sic)H2(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)Ni/CeO2(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic),(sic)(sic)(sic)(sic)(sic)4.9 nm(sic)A-Ni/CeO2(sic)(sic)(sic)(sic)225 degrees C(sic)(sic)(sic)(sic),(sic)(sic)(sic)83.4%(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)similar to 100%(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)H2/D2(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(DFT)(sic)(sic)(sic)(sic),(sic)(sic)(sic)H2(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)H2(sic)(sic)(sic)CO2(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)CO2(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).

Green methanol could help decarbonize transport and industry, but its production roadmap remains uncertain because biomass conversion, renewable hydrogen supply, the emissions and cost of electricity are tightly coupled. Here we show, using pilot-scale gasification data and industrial process parameters, how four biomass- and renewable-power-based methanol routes differ in technical performance, life-cycle greenhouse gas emissions and production cost, and identify deployment-relevant boundary conditions. Gasification integrated with renewable hydrogen balances carbon utilization and energy efficiency, reaching 92% and 54%, respectively. Direct combustion followed by carbon dioxide hydrogenation raises carbon utilization to 96% but requires substantially more electrolysis-derived hydrogen. Under hybrid wind and solar power, all routes remain below the European low-carbon fuel threshold, although the maximum electricity emission factors compatible with this threshold vary from 0.057 to 0.373 kilograms of carbon dioxide equivalent per kilowatt-hour. Gasification without added hydrogen is currently the least-cost route. Hydrogen-integrated gasification approaches its cost when renewable electricity falls below US$21 per megawatt-hour, and approaches coal-based methanol costs at carbon prices of US$40-90 per tonne of carbon dioxide. These results define practical boundaries for route deployment. The study compares four routes for producing green methanol from biomass and renewable power, revealing trade-offs in carbon use, energy efficiency, emissions and cost, and identifying the deployment boundaries for each route.

Amines are important atmospheric basic gases that contribute to secondary particle formation via acid-base reactions, affecting air quality and human health. In urban atmospheres, their clustering with sulfuric acid is the key pathway driving new particle formation and growth into cloud condensation nuclei, with consequences for climate. Elevated amine levels have been observed in traffic environments, yet direct tailpipe evidence remains scarce. Here, we provide unambiguous identification and quantification of amines and their derivatives in the exhaust of heavy-duty diesel vehicles (HDDVs). Our results show that these compounds originate predominantly from transformations of ammonia (NH3) released during overdosing of diesel exhaust fluid (DEF, an aqueous urea solution) in selective catalytic reduction (SCR) systems. Instantaneous patterns further demonstrate that amine formation requires the coexistence of NH3 and oxygenated volatile organic compounds. The tested China VI fleet exhibited lower NOx emissions than China V vehicles, but more pronounced NH3 overdosing, likely leading to higher amine-related emission factors (EFs). Furthermore, both amine and NH3 EFs increased with vehicle mileage, indicating emission deterioration associated with aging SCR-related aftertreatment components. Our findings highlight that the environmental implications of SCR-based NOx control extend beyond NOx reduction, as excessive NH3 dosing enhances amine emissions and also stimulates secondary particle formation, with broader impacts on air quality and climate.

Hydrogen fuel cell electric trucks (FCETs) have been seen as an important decarbonization pathway for heavy-duty trucks, but their real-world operational performance and costs remain uncertain, posing challenges to the widespread adoption. This study presents the largest analysis to date of real-world operational data from 106 heavy-duty FCETs across six application scenarios in China. We examine usage patterns, energy consumption, life-cycle greenhouse gas (GHG) emissions, and total cost of ownership (TCO). FCETs are deployed across diverse application scenarios, with most operating on short- to medium-distance routes (average daily mileage <300 km), and some utilizing both hydrogen refueling and grid charging. In Beijing, where hydrogen is primarily sourced from industrial byproducts, FCETs generally exhibit lower life-cycle GHG emissions than diesel and battery-electric trucks, except in low-utilization scenarios. Currently, the unsubsidized TCO of FCETs is 42-152% higher than that of diesel trucks (DTs). However, with purchase, operational, and hydrogen subsidies, the TCO can be 13-36% lower than that of DTs. While FCETs offer strong carbon reduction potential, achieving TCO parity requires alignment with appropriate application scenarios and adequate refueling infrastructure, particularly for long-haul operations by 2030.

Converting CO 2 to CH 4 under mild conditions is a promising strategy for solving environmental and energy problems, but also a challenge. In this work, the low‐temperature CO 2 hydrogenation process over Ni/CeO 2 catalysts was significantly accelerated by optimizing the H 2 dissociation ability of Ni through the size effect, thus A‐Ni/CeO 2 with an average size of 4.9 nm achieved 83.4% CO 2 conversion with ∼100% CH 4 selectivity even at 225°C. Systematic H 2 /D 2 isotopic exchange experiments, in situ spectroscopic characterizations, and density functional theory (DFT) calculations reveal that the enhanced H 2 activation ability not only promoted the creation of oxygen vacancies and hydroxyl group favorable for CO 2 adsorption/activation in the pre‐reduction process, but also the simultaneous hydrogenation of reactive intermediates belonging to carbonyl and formate pathway into CH 4 in the reaction process. This fundamental understanding of the H 2 dissociation effect on CO 2 activation and hydrogenation provides critical insights for designing catalysts with considerable low‐temperature activity, which significantly reduces energy consumption and operating costs for industrial CO 2 conversion.

Climate change mitigation requires profound decarbonization of the transportation sector. As a transitional technology bridging internal combustion engine vehicles (ICEVs) and battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs) play a crucial role. This study evaluates the life-cycle CO2 emissions of PHEVs in China from 2015 to 2022, with particular focus on key factors of increased battery range, decarbonization of the power mix, and variations in electric utility factors. During the study period, PHEV battery capacity demonstrated significant growth: from 10.3-14.2 kWh to 13-20 kWh for short-range models, while long-range models with 30-40 kWh batteries emerged. Our analysis reveals that while larger battery capacities increase production-related emissions, they enhance the regulatory UF, thereby reducing well-to-wheel (WTW) CO2 emissions. For typical Chinese PHEV models (50-220 km AER in 2022), cradle-to-grave (C2G) CO2 emissions showed limited sensitivity to AER variations (<5 gCO(2)/km). However, the gap between regulatory and realworld UF, primarily driven by charging behavior, can significantly impact decarbonization outcomes (15-25 gCO(2)/km). Notably, PHEVs demonstrated a 40-50 gCO(2)/km reduction in C2G missions compared to ICEVs, while maintaining a 30-40 gCO(2)/km gap relative to BEVs currently. With further improvement in efficiency, UF increases, material and grid decarbonization, PHEVs are estimated to achieve similar to 110 gCO(2)/km C2G missions by 2030. These findings emphasize the need for optimizing charging infrastructure and policy adjustments to align with user behavior, thereby maximizing the decarbonization potential of PHEVs.

Greenhouse gas emissions (GGE) have crucial effects on the global climate. Although prior research on GGE in the aluminum electrolysis industry (AEI) focused on carbon dioxide (CO2) and perfluorocarbon (PFC) emissions, we have discovered significant nitrous oxide (N2O) emissions from this sector, which has been overlooked until now. In this work, we found that N2O had a CO2 equivalent (CO2eq) emission factor twice that of CO2 or PFCs. We also identified a significant linear relationship between the N2O emission factor and the product of the electrolysis cell number, the anode effect coefficient, and the duration. Based on the above results, we estimated that global N2O emissions from the AEI reached 65.1 +/- 6.4 Mt of CO2eq/year in 2018. The newly discovered N2O emissions constituted 27.4-52.2% of total GGE in the AEI and 15.7-65.1% of existing industrial N2O emissions. These findings highlighted that the AEI was a long-neglected source of N2O emissions. The N element content control in carbon anodes may be an effective measure to reduce N2O emissions during the processing of the anode effect. Additionally, the molten salt electrolysis process for production of metals such as sodium, magnesium, and lithium may also be a potential source of N2O emissions and is necessary to further investigate N2O reduction technologies.

The efficient degradation of antibiotics in wastewater is critical for addressing global water pollution challenges. Herein, we report an Fe-Co dual-atom catalyst anchored on a nitrogen-doped carbon matrix (FeCo/NC), which demonstrates superior performance in peroxymonosulfate (PMS) activation and tetracycline (TC) degradation. This system achieves a remarkable TC removal efficiency of 91.2%, significantly outperforming single-atom catalysts. Mechanistic investigations reveal that FeCo/NC induces a unique spin-state reconstruction, optimizing its electronic structure and shifting the oxidative mechanism from a radical-driven pathway to a singlet oxygen (1O2)-dominated nonradical process. Theoretical insights from density functional theory (DFT) calculations confirm the preferred 1O2 generation pathway at FeCo active sites, with reduced energy barriers that enhance catalytic activity. Toxicological evaluations validate that TC degradation intermediates exhibit minimal ecological risks, reinforcing the environmental safety of this approach. The long-term stability of the FeCo/NC/PMS system was evaluated via a continuous-flow photocatalytic reactor. The above results reflect the superior catalytic activity and stability of the FeCo/NC/PMS system. This work establishes a paradigm for designing advanced dual-atom catalysts and provides critical insights for developing eco-friendly solutions to antibiotic-contaminated wastewater treatment.

Biomass burning (BB) emits carbonaceous aerosols that significantly influence air quality in Southwest China during spring. To further understand the characteristics of spring BB and its original contribution to organic carbon (OC), daily fine particulate matter (PM2.5) samples were collected from March to May 2022 in Pu'er, Southwest China. The concentrations of OC, elemental carbon (EC), levoglucosan (Lev), and potassium from BB (K+BB) during the study period ranged from 5.3 to 31.2 µg/m3, 0.86-13.1 µg/m3, 0.06-0.82 µg/m3, and 0.05-2.88 µg/m3, respectively. To eliminate the effects of Lev degradation, this study uses the Aging of Air Mass (AAM) index to correct the atmospheric concentration of Lev and combines Bayesian mixture modeling with a molecular tracer method to assess the original contribution of BB to OC. The results indicated that the AAM index was 0.18 ± 0.05, indicating that the degradation of Lev reached 82 %. When considering the degradation of levoglucosan in the atmosphere, the primary source of BB aerosols was crop-straw combustion (71.1 %), followed by the combustion of certain hardwoods and softwoods (24.9%) and grasses (4.0 %). The original contribution of BB to OC was 62.4 %, which was much greater than the contribution when levoglucosan degradation (23.7 %) was ignored. The air mass inverse trajectories and Moderate Resolution Imaging Spectroradiometer (MODIS) fire hotspots indicated that the BB plume from Southeast Asia during spring could influence PM2.5 long-range transport in remote locations, and the contribution could reach 82 % in Southwest China.

Aliphatic carbonyls widely exist in source emissions and the atmosphere, serving as secondary organic aerosol (SOA) precursors. Molecular structure including carbon number and functional groups influences SOA formation. However, limited research was conducted on the vastly different SOA yields among aliphatic carbonyls, and the impact of the molecular structure remains unclear and controversial. In this study, 11 aliphatic carbonyls were photooxidized to study the SOA formation and gas-phase products in an oxidation flow reactor (OFR). The maximum SOA yields of C15 and C13 straight-chain carbonyls are 0.41-0.52 and 0.18-0.23, lower but within a comparable range with long-chain alkanes, whereas those for C8-C10 carbonyls are less than 0.04. Aliphatic carbonyls with more carbon have significantly higher SOA yields, accompanied by additional multigenerational products. The SOA yield of n-aldehyde is moderately higher than that of n-alkan-2-one with the same carbon number, due to the enhanced formation of long-chain acids with lower volatility than dicarbonyls. The saturated cyclic structure increases the SOA yield by forming more multifunctional products with additional aldehyde groups upon ring-opening, whereas the branched structure easily fragmented and decreased the SOA yield. This study highlights that the aliphatic carbonyls with more carbon numbers and a cyclic structure with less branching may have higher SOA yields.

Mercury emissions from human activities persist in the environment, posing risks to humans and ecosystem, and are regulated by the Minamata Convention. Understanding historical mercury emissions is critical for explaining their presence in the environment, and a long-term gridded emission inventory is essential for simulation and evaluation. While previous studies have improved the spatial resolution of emission inventories for recent years, few have combined long timescales with high spatial resolutions. Here, we compile a new comprehensive point source database by fusing multiple data sources and integrate it with the previous China Atmospheric Mercury Emission model to develop a long-term gridded emission inventory for China, covering 1978–2021, named P-CAME. By integrating point sources, P-CAME improves the accuracy of gridded emissions, reducing the normalized mean error by 108 % compared to an inventory without point sources for the most recent year of 2021. P-CAME highlights potential pollution hotspots, revealing that 20 % of cumulative emissions originate from just 0.3 % of the grids, primarily in the provinces of Gansu, Yunnan, and Hunan. These areas are dominated by non-ferrous metal smelting or mixed emissions from coal-fired industries and cement production. P-CAME also demonstrates consistency with observed Hg0 (gaseous elemental mercury) concentration trends over the past decade and shows potential to enhance the simulation of atmospheric mercury concentrations in urban areas, though its capacity is still limited by overall model performance. With improvements in terms of spatial distribution accuracy and reliable long-term trends, this updated inventory will provide valuable data support for global emissions modeling, facilitate assessments of mercury cycling and legacy impacts, and aid in the evaluation of the Minamata Convention. The dataset can be found at https://doi.org/10.6084/m9.figshare.26076907 (Cui et al., 2024).