Severe convective weather (SCW) is one of the primary meteorological phenomena causing significant disasters and casualties in China. Since 2009, the National Meteorological Center (NMC) of the China Meteorological Administration has made remarkable progress in SCW monitoring, forecasting, and warning technologies and operations. This paper summarizes the operational developments and scientific achievements of the NMC with respect to SCW from four aspects: operations, mechanism studies, monitoring and forecasting technologies, and operational platforms. The NMC has established a comprehensive operational system for SCW, achieving continuous improvement in forecast accuracy and refinement. Key advances are as follows: The climatological characteristics and environmental conditions of SCW in China have been revealed, along with the impacts of the Asian monsoon and cold vortices on convective storms. Identification technologies have been developed for tornadoes, thunderstorm winds, and downbursts using multi-source observations, physical structure characteristics, and deep learning (DL) algorithms. By integrating multi-source observational data with numerical weather prediction and applying DL methods, DL models for nowcasting (0–2 h), short-term (0–12 h) and short-range (0–72 h) forecasting have been constructed, with the Fenglei nowcasting model achieving a reliable 3-h forecast. The SWAN (Severe Weather Analysis and Nowcasting) platform, version 3.0, has been implemented, enabling real-time coordinated nowcasting across all-level meteorological departments for the first time in China. Future efforts will focus on enhancing high-precision observation networks, advancing ultra-high-resolution numerical models, developing large-scale and specialized models by integrating physical mechanisms and DL methods, and addressing key technical challenges including high false alarm rates, limited lead time, and intensity prediction difficulties.

Heatwaves and surface ozone pollution frequently co-occur during the warm season, posing compound environmental and health risks. However, the long-term evolution of different heatwave types and their influences on ozone pollution remain insufficiently characterized across China. Using CN05.1 daily maximum and minimum temperature data, the ChinaHighAirPollutants surface ozone product, ERA5 reanalysis variables, and selected socioeconomic and environmental indicators, this study examined daytime heatwaves (DHWs), nighttime heatwaves (NHWs), compound day-night heatwaves (CHWs), ozone pollution, and heatwave-ozone compound event days across China during 2000–2024. Conditional probability and risk-ratio analyses were conducted for six regional domains, while multiscale geographically weighted regression (MGWR) was used to characterize spatially varying ozone associations. Results showed significant nationwide increases in all heatwave types, ozone levels, and compound events, with NHWs and CHWs rising faster than DHWs. Ozone pollution exhibited a pronounced east-west gradient, with hotspots in the North China Plain and Yangtze River Delta, and compound events expanded substantially after 2015 beyond traditional hotspots. Heatwaves significantly elevated ozone probability, with DHWs exerting the strongest influence and CHWs prolonging ozone exposure through persistent favorable conditions. Beijing-Tianjin-Hebei region showed the highest conditional ozone probabilities, whereas the Sichuan Basin displayed the largest relative increase compared with non-heatwave conditions. MGWR revealed pronounced spatial heterogeneity: Maximum temperature and solar radiation generally showed positive associations with ozone, while relative humidity showed predominantly negative associations; temperature sensitivity of ozone increases markedly in Beijing-Tianjin-Hebei, Central China, and Eastern China between 2010 and 2020. Overall, climate warming intensifies both heatwave-ozone compound events and climatic sensitivity of ozone pollution, underscoring the need for integrated climate adaptation and air-quality management.

Dynamic temperature fluctuations are a key driver of morbidity and mortality. To characterize the health impacts of drastic temperature fluctuations, a novel metric was developed to calculate real-time temperature deviation (TD) from previous exposures (hypothetical adaptation baseline). We used quasi-Poisson models to investigate the association between TD and cause-specific mortality in four Chinese megacities with distinct climatic conditions. Cause-specific mortality data were collected from Harbin, Beijing, Chengdu, and Shanghai between 2010 and 2016, comprising 249,110 respiratory and 740,925 cardiovascular death cases. Seasonal temperature trends were incorporated as effect modifiers. Rapid warming increased mortality risks across all cities, yet pronounced north–south divergence existed in population vulnerability. Negative TD yielded significant protective effects during warming seasons. The subtropical Shanghai exhibited the highest risks associated with P90-level TD, with RRs reaching 1.063 (95% CI: 1.038–1.089) for respiratory mortality and 1.076 (95% CI: 1.060–1.092) for cardiovascular mortality. Northern residents were susceptible to rapid warming as well as extreme temperature declines in cooling periods, with higher mortality risks from respiratory diseases than cardiovascular diseases. In comparison, southern residents suffered excess mortality risks from both abrupt warming and frequent moderate cooling events. At P10 of TD0-7, the highest RRs of cardiovascular and respiratory mortality were found in Chengdu (RR=1.015, 95%CI: 1.005–1.025) and Shanghai (RR=1.019, 95%CI: 1.005–1.033), respectively. Our findings reveal substantial geographical and seasonal heterogeneity in the health impacts of dynamic temperature fluctuations, highlighting the need for flexible, location- and season-specific health risk mitigation and climate adaptation strategies.

Vertical wind shear frequently occurs in complex terrain (basin and sloped terrain). However, compared with thermodynamic (temperature inversion) variables, the modulation of dynamic (wind shear) variables on air pollution is poorly understood due to scarce in-situ observations at complex terrain. In order to reveal the issues, we conducted the first collaborative field experiment of Boundary-Layer Meteorology and Pollution at western Sichuan Basin (BLMP-SCB) at a rural site from December 2018 to January 2019. A clockwise turning of the wind with the height was more frequent, especially for the rotation smaller than 20 degrees, which corresponded to the heavy air pollution near the ground surface. The surface heavy air pollution was jointly influenced by both low-level wind-directional shear and speed shear above that layer, especially the configuration of southeasterly winds below 1.0 km above sea level (regional transport) and increased southwesterly winds with height above the height (subsidence motion). The elevated wind-directional shear enhanced mechanical turbulence to transport downwards secondary pollutants to upper atmospheric boundary layer from the higher layer of air. The increased wind speed with height more easily triggered subsidence motion to trap more pollutants inside the basin. The work was helpful for fully understanding the role of meteorological variables in the formation and development of heavy air pollution at complex terrain, which will be favorable for making targeted pollution prevention and control measures at complex terrain.

Anxiety and depression are the most common mental health issues among adolescents, and the impact of air pollution on mental health is gaining increasing attention. This study aims to investigate the association between air pollutant exposure and the risks of anxiety and depression among adolescent students in Sichuan Province, China. This study used cross-sectional data from 71,364 school students aged 10 to 19 in Sichuan Province, China, collected during two winter periods: December 2022 to March 2023 and December 2023 to March 2024. PHQ-9 and GAD-7 assessed anxiety/depression (scores ≥ 5); pollution (PM10, PM2.5, O3, CO, SO2, NO2) and weather data via IP informed weighted combined pollution score for exposure. Logistic regression and mixed-effects linear models were employed to evaluate the associations, adjusting for demographic, lifestyle, family-related, and meteorological factors. Both PM10 and O3 showed robust positive associations with mental health risks. In the fully adjusted model (Model 4), each interquartile range (IQR) increase in PM10 and O3 was associated with increased risks of anxiety (OR: 1.29, 95

While daytime heatwaves are well-known to exacerbate surface ozone (O3) pollution, the role of compound heatwaves with persistent day-night hot in O3 pollution remains unclear. Taking China's Sichuan Basin (SCB) as an example, we find compound heatwaves persistently intensify surface O3 concentration day and night, with significant positive anomalies of 29.3 mu g/m3 and 12.1 mu g/m3 during daytime and nighttime, respectively. In details, daytime hot triggers high daytime O3 concentration by enhancing O3-forming photochemistry, thereby providing a nocturnal residual layer (RL) with O3-rich air and substantial heat storage. Nighttime, the persistent day-night hot combined with easterly flow jointly drive a plateau-basin secondary circulation across RL and stable boundary layer over the SCB, facilitating RL's O3-rich air mixing to the surface and increasing nighttime O3 concentration. These findings advance understanding of how extreme heat and large-scale topographic forcing jointly modulate atmospheric environmental changes in plateau-basin regions.

Chinese cities face escalating tensions between pollution mitigation and economic equity. Using an environmentally extended multi-regional input–output (EE-MRIO) model, we quantified the carbon and air pollutant footprints of 309 cities from 2012 to 2017 and applied structural decomposition analysis (SDA) to identify key emission drivers. The results indicate that inequality in air pollutant emissions, with a Gini coefficient of 0.31–0.53, is significantly higher than that of CO2 (0.33–0.41). Developed cities generate 3.1 times more economic output per unit of CO2 emissions than less developed cities, with the disparity widening over time. While intermediate input optimization contributed to a 1.94 Gt reduction in CO2 emissions, its benefits were largely concentrated in developed regions and were accompanied by increased emissions of PM2.5, BC, OC, and CO. Although reductions in emission intensity played a crucial role in mitigating pollutants, they paradoxically contributed to CO2 growth in energy-intensive cities. Additionally, population growth and per capita final demand were the primary drivers of emission increases, and population growth had a greater impact on developed regions. These findings underscore the need for regionally differentiated policies, including carbon quota reallocation, industrial transformation in energy-dependent cities, and the promotion of green industries in less developed areas, to achieve a balance between environmental sustainability and economic development.

Tropospheric ozone (O3) is a ubiquitous pollutant that is detrimental to human health and ecosystems. The Sichuan Basin (SCB), one of the most populous city clusters in China, has experienced more-intense O3 pollution episodes and longer O3 season with more-frequent stagnant conditions over the past decade. In 2022, the prolonged O3 season featured extremely high levels of O3 and region-wide O3 events were observed, posing significant threats to public health. However, it remains unclear to what extent meteorological fields could contribute to O3 anomaly and to the adverse health impacts from extreme O3 season. Here, we investigate the drivers of extreme summer O3 pollution in 2022 over the SCB using a high-resolution Community Multiscale Air Quality (CMAQ) model in conjunction with surface air quality measurements. Further, the health effects of exposure to high levels of O3 are quantified using the Environmental Benefits Mapping and Analysis Program (BenMAP). Both meteorological reanalysis data and the Weather Research and Forecasting (WRF) modeling revealed extreme heat featured by persistent heatwaves in the study period, which significantly perturbed daytime photochemical reactions and primed the landscape for elevating O3. Sensitivity experiments with fixed anthropogenic emissions indicate that unfavorable meteorology and subsequent enhancements in biogenic emissions substantially contributed to O3 anomaly. Importantly, this unprecedented O3 season resulted in 48285 all-cause deaths due to long-term exposure, which is 8064 higher than the same period in 2019 and significantly overtake previous recognition. CMAQ simulations point to that O3 elevation could be partially offset by concurrent 50 % emission reductions on nitrogen oxides (NOx) and volatile organic compounds (VOCs), leading to avoided deaths of 2660. This work highlights the underestimated O3-related mortality burden and pinpoints the necessity of stringent emission regulations toward O3 mitigation in basin topography.

Inorganic nitrogen aerosols, specifically nitrate (NO3-) and ammonium (NH4+), represent dominant components of wintertime PM2.5 pollution in the topographically confined Sichuan Basin, where frequent atmospheric stagnation and persistently high humidity favor aerosol formation and accumulation. However, owing to the complexity of their emission sources and the nonlinear response of aerosol formation to precursor reductions, targeted investigations are essential for developing region-specific nitrogen control strategies. This study conducted the first simultaneous measurement of δ15N in PM2.5 NO3- and NH4+, combined with δ15N-δ18O analysis of NO3-, to elucidate their co-evolution processes and sources contributions in a megacity within Sichuan Basin during February 2023, a period marked by persistently high relative humidity at 74 ± 11 %. The mass concentration of NO3- and NH4+ together averaged 23.8 ± 10.2 μg/m³ (ranging from 7.7 to 43.9 μg/m³), constituting 21.5-75.0 % of PM2.5. Approximately 58 % of the NO3- originated from the hydrolysis of nitrogen pentoxide (N2O5), a process that reached up to 73.3 %. Isotope-based source apportionment, resolved using the Bayesian isotope mixing model (MixSIAR), revealed that biomass burning (24.4 ± 17.7 %), traffic (22.9 ± 17.6 %), coal combustion (22.7 ± 13.9 %), and natural gas combustion (16.1 ± 11.6 %) were the predominant contributors to urban NOx. For NH3 emissions, nonagricultural activities (52.7 ± 13.4 %) dominated through biomass burning (20.5 ± 16.2 %), traffic/industry (17.3 ± 13.1 %), and sewage treatment (14.9 ± 10.9 %), exhibiting enhanced contributions (reaching up to approximately 70 %) on a polluted day. These results highlight the necessity of prioritized controls on reactive nitrogen gas emissions from nonagricultural sources, specifically traffic, coal-fired industries, and biomass burning, to effectively mitigate winter haze formation in the NH3-rich and humid Sichuan Basin.

The Sichuan Basin (SCB), located in Southwest China, often has serious ozone (O3) pollution due to its special topography, complex meteorological conditions and emissions. The frequent occurrence of extreme high temperature has recently aggravated the biogenic O3 precursors emission and the O3 pollution in the SCB. To quantify the O3 pollution caused by high temperature, the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) was used to study the formation mechanism and transport process of the O3 pollution event in the SCB in July 2022, after updating emission information with TROPOMI satellite data and MEGAN model initial data. The results show that during the pollution period, the SCB was affected by the alternating effects of the circulation changes caused by the eastward movement of the northern continental high pressure and the westward movement of the western Pacific subtropical high pressure. The continuous control of the high pressure formed extremely high temperature, which led to the accelerated generation of O3 in the SCB. The southeastern continental high pressure and the northwestern subtropical high pressure converged in the SCB, forming a "zigzag"-shaped circulation, which prevented O3 from being transported out of the SCB. The results of integrated process rate analysis (IPR) show that the negative contribution of horizontal advection accelerates the O3 output from the cities in the middle of the SCB to the surrounding cities, resulting in the rapid spread of pollution over the SCB, the O3 accumulation in the high altitude of the basin, and the positive contribution of chemical generation in the south of the SCB.

In the context of climate change, there is a trend of earlier onset and longer duration of ambient ozone (O3) pollution in the Sichuan Basin (SCB). On 21-March 26, 2024, an O3 exceedance event occurred in the Chengdu Plain and southern SCB during early springtime, when moderate pollution rarely emerged before. The environmental and meteorological observation data, reanalysis dataset, and the WRF-Chem model coupling Integrated Process Rate (IPR) method were employed to examine the synoptic patterns and the transport mechanisms conducive to O3 pollution episode. The statistical results showed that MDA8 O3 concentration exceeding 160 μg/m3 amounted to 40 and 63 stations on the 22nd and 23rd in the SCB, respectively. The maximum MDA8 O3 of 222 μg/m3observed on the 23rd in Zigong located in southern SCB. The synoptic pattern revealed that it was the successive arrival of the southern trough and plateau trough that made the southwestern basin to be controlled by a warm low-pressure system, which consequently led to pollutant accumulation. The strong vertical advection was the reason for the ground-level O3 surge during the first pollution stage of March 21st to 23rd. Under the influence of northwesterly winds, the O3-enriched air parcel was subsequently conveyed downstream to southern SCB, with the elevated local temperature exacerbating the O3 formation. The contribution of horizontal advection was ∼9.03 times higher than the chemical contribution in the southern SCB. During the pollution's later stage, increased wind speed and presence of precipitation were crucial for the enhanced vertical mixing, which ultimately leaded to the O3 decrease. Our result advances early spring O3 pollution mechanism and their interactions with distinctive topographic and meteorological conditions over the SCB.

In the context of global warming, the frequency and intensity of extreme weather events are intensifying. Although cold waves have significant impacts on human health, related research remains insufficient. This study integrates high-resolution population dynamics and temperature data to assess cold exposure risks during cold waves in Beijing, addressing a critical research gap in urban public health. We have developed an advanced cold exposure risk assessment framework aimed at uncovering the potential health threats posed by winter cold waves to urban residents. Our findings reveal that population movement between urban and suburban areas significantly affects cold exposure risks, with nighttime dynamics exacerbating exposure levels. Specifically, nighttime population dynamics substantially exacerbate cold exposure levels, while daytime population dynamics, due to the urban heat island effect, to some extent reduce cold exposure risks. Additionally, compared to traditional average temperature metrics, dynamically population-weighted temperatures more accurately reflect actual cold exposure risks. The findings of this study provide valuable insights for urban public health management, emphasizing the importance of considering population mobility in public health strategies for responding to extreme weather events.

Fine particulate matter (PM2.5) pollution is a critical air quality concern which poses threats to public health. Despite strict air pollution control measures implemented in China since 2013, PM2.5 exceedances and region-wide PM2.5 episodes are still frequently observed in the Sichuan Basin (SCB) located in southwestern China. Here, we examine ambient PM2.5 pollution within the SCB from 2013 to 2020, focusing on emission sources, trends, and health outcomes. By integrating ambient measurements, emission inventories, and the health impact model, our findings reveal a notable decrease in PM2.5 levels across the basin, with the Chengdu Plain showing a significant reduction of 56 μg/m3 in 2020 compared to 2013. Despite these improvements, it is still challenging for densely populated cities to attain the national air quality standards. We highlight a 46.8 % reduction in PM2.5 emissions from 2013 to 2020, driven largely by decreased emissions from residential and industrial sources, which accounted for an average of 38.6 % and 50.3 % of total reduced emissions, respectively. In contrast, the decreases of NOx emissions (26.0 %) were less pronounced compared to PM2.5 due to modest reductions from industrial and transportation sectors. Health impact assessments at 1 km × 1 km using the GEMM model attributes 157,637 deaths to long-term PM2.5 exposure in the SCB for 2017, with stroke and ischemic heart disease identified as leading causes. Further analysis indicates that significant variations in population density could greatly amplify the health impacts of long-term PM2.5 exposure, highlighting the need to prioritize PM2.5 reduction strategies specifically targeting megacities to maximize health benefits. These findings underscore the critical need for ongoing emission reduction efforts and the implementation of targeted pollution control measures to further improve air quality and reduce mortality burden in the SCB.

Long-range transport of biomass burning aerosols from Eastern Siberia to Northeast China in July 2014 was studied by using ground-based ambient measurements and satellite products. Intensive active fires were revealed in Eastern Siberia during the late of July by the Moderate Resolution Imaging Spectraradiometer (MODIS) active fire products. Under the favorable synoptic pattern, the smoke layer was transported to Northeast China, which led to significant enhancement of surface PM2.5 concentration. The peak PM2.5 concentration exceeded 100 μg m−3 that was 3–6 times larger than the background level. High aerosol optical depth at 550 nm with daily value exceeding 1.0 was observed at a background site in Northeast China. Smoke aerosols were characterized by fine-mode dominated particles with very weak absorption. Air quality in Northeast China was revealed to be potentially impacted by the long-range transport of smoke aerosols from Eastern Siberia during the biomass burning season, which probably impacted human health, weather and climate. Therefore, futher study on this issue is urgenly required for quantitatively evaluating potential contribution of long-range transport to regional air pollution in Northeast China.

Strong upwards transport of Nitrous acid (HONO) in daytime over urban area of Beijing was observed based on combined observations of HONO, NOx (NO and NO2), nitrate, and PM 2.5 at two heights (90 m and 528 m) on the highest building of Beijing (528 m above ground). The mean HONO at the 528 m (0.26 ppb) was lower than that at the 90 m (0.54 ppb), and a clear difference in diurnal variation of HONO between the two heights was observed. HONO at the 90 m showed two peaks in the morning rush hour and mid-night, but decreased sharply in daytime (e.g., from 0.62 ppb at 08:00 to 0.34 at 14:00); while the decreasing trend of HONO in daytime significantly weakened at the 528 m (e.g., from 0.26 ppb at 08:00 to 0.27 at 14:00).With PBL development in the morning, HONO in low layer was upwards transported to the 528 m, which compensated partly HONO loss via photolysis and resulted in a relatively stable concentration at the 528 m in daytime. A positive relationship of the bulk Richardson number (Ri) in 0-500 m with the difference of HONO between the two heights during daytime (08:00-18:00) confirmed the above analyses. HONO budget analysis indicated that a strong unknown HONO source existed at the 528 m in daytime, which was negative correlated to the Ri. These results further confirmed that vertical transport of HONO from low layer was a potential HONO source at the 528 m. Moreover, the contribution of photolysis of particulate nitrate significantly increased at the 528 m. Its contribution in total HONO sources increased from 11.9 % at the 90 m to 16.0 % at the 528 m.

Vertical distributions of chemical components of particulate matter (PM) are essential for better understanding the climate, environmental and health effects. The steep slope from western SiChuan Basin (SCB) to eastern Tibetan Plateau (TP) provides a good platform for obtaining the gradient variations of PM chemical components. Daytime and nighttime PM1 (particulate matter smaller than 1 mu m) samples were collected with the medium- volume sampler at six sites with elevation ranging from 500 m to 3500 m (Chengdu, Sanbacun, Wenchuan, Lixian, Maerkang and Hongyuan). The secondary inorganic ions and carbonaceous aerosols were the largest contributor to PM1 concentrations. The chemical components from the anthropogenic sources existed strong stratification with high concentrations inside the basin, while primary natural ions showed little discrepancy among the sites. The concentrations of primary inorganic ions from anthropogenic sources were much higher at nighttime than daytime, which was contrary to the diurnal cycle of secondary inorganic ions. Spatial heterogeneity of PM chemical components was large between basin and plateau sites, especially for NO3- and NH4+, large depending on season and daylight. The excess NH4+ concentrations existed in spring, summer and fall, while SO42- and NO3- cannot be completely neutralized by NH4+ in winter. The proportion of secondary formation in all sources significantly increased from about 10 % to 30 %-40 % with the increased elevation, while the contribution of motor vehicles declined from western SCB to eastern TP. This study will fill the scarce observations of PM chemical components at the sloped terrain and deepen the understanding of formation mechanism of heavy pollution inside the basin.

Chengdu Plain Urban Agglomeration (CPUA) is one of the most serious areas of ozone pollution in China. A comprehensive field experiment focused on the ozone episode characteristics, and temporal and spatial variations of ozone production rate was conducted at CPUA in the summer of 2019. Six sampling sites were set and two ozone pollution episodes were recognized. The daily maximum 8-h average (MDA8) O3 concentration reached 137.9 ppbv in the urban sites during the ozone episode. The high concentration of O3 was closely related to intense solar radiation, high temperatures, and precursor emissions. Based on the calculation of OBM, the OH-HO2-RO2 radical chemistry and ozone production rate (P(O3)) was analyzed. The OH daily maximum is in the range of 3-13×106 molecules cm−3, and HO2 and RO2 are in the range of 2–14×108 molecules cm−3 during ozone episodes, varying by the location of sites. During ozone episode, the average maximum of P(O3) in suburb sites (about 30 ppb h-1.) were compared with urban sites, while the maximum of P(O3) was 18 ppb h-1 in rural sites. The relative incremental reactivity (RIR) and empirical kinetic modeling approach (EKMA) results demonstrate that centered on the urban area of Chengdu, where it was a VOC-limited regime, the northern and southern suburban area was transition region. In the remote rural area of the southern CPUA, it was highly NOx-limited. Local ozone production driven by the photochemical process is important for CPUA. The geographically differentiated recognition of the ozone regime found by this study can help to tailor control strategies for local conditions and avoid the negative effects of a one-size-fits-all approach.

Urban heat waves pose a significant risk to the health and safety of city dwellers, with urbanization potentially amplifying the health impact of extreme heat. Accurate assessments of population heat exposure hinge on the interplay between temperature, population spatial dynamics, and the epidemiological effects of temperature on health. Yet, many past studies have over-simplified the matter by assuming static populations, leading to substantial inaccuracies in heat exposure assessments. To address these issues, this study integrates dynamic population data, fluctuating temperature, and the exposure-response relationship between temperature and health to construct an advanced heat exposure assessment framework predicated on a population dynamic model. We analyzed urban heat island characteristics, population dynamics, and heat exposure during heat wave conditions in Beijing, a major city in China. Our findings highlight significant intra-day population movement between urban and suburban areas during heat wave conditions, with spatial population flow patterns showing clear scale-dependent characteristics. These population flow dynamics intensify heat exposure levels, and the disparity between dynamic population-weighted temperature and average temperature is most pronounced at night. Our research provides a more comprehensive understanding of real urban population heat exposure levels and can furnish city administrators with more scientifically rigorous evidence.

为揭示四川盆地城乡人群的PM2.5暴露风险特征,通过比较PM2.5暴露强度(EI)、基于原始浓度的PM2.5暴露风险(R)和基于人口加权浓度的PM2.5暴露风险(R*)3种评估指标,对四川盆地17个城市共80个国控环境监测站点2016-2020年的PM2.5浓度数据进行分析,并利用综合暴露-响应(IER)模型对四川盆地2016-2020年年均归因于PM2.5污染的疾病致死人数进行评估.结果表明:①在四川盆地R*是一种综合考量人口分布及人群环境暴露参数的PM2.5暴露风险评估指标,春、秋季R*高值区集中分布在盆地中西部及南部,夏季R*高值区集中分布在盆地中西部,冬季R*高值区扩展到整个盆地中部及东部,且各季节R*低值区主要位于盆地周边地区,四川盆地2016-2020年年均R*最大值、最小值分别出现在成都(2.296× 10-5)、雅安(3.072× 10-6),与人口分布的一致性表明未来PM2.5暴露风险防控重点区域应着眼于人口集中的地区;②从城乡人群差异看,城市人群R*值于45～＜60岁(12～＜15岁)达到最高(低)值,18岁以上成年人群的R*值比18岁以下未成年人群高;农村人群R*值于9～＜12岁(15～＜18岁)达到最高(低)值,成年人群中峰值出现在18～＜45岁人群;③四川盆地2016-2020年年均可归因于PM2.5污染的健康损失(即过早死亡人数)为12.65万人,其中由中风(STK)、缺血性心脏病(IHD)、慢性阻塞性肺病(COPD)和肺癌(LC)4种疾病导致的过早死亡人数占比分别为52.42％、26.54％、13.37％和7.67％,表明四川盆地大气污染导致的健康负担仍然很重,需要实施更加严格的空气污染控制政策.