ArticlePublisher preview available

Hospital admissions attributable to reduced air pollution due to clean-air policies in China

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract and Figures

The Air Pollution Prevention and Control Action Plan (APPCAP) is considered to be the most stringent air pollution control policy in China implemented since 2013. This policy is a milestone in China to mitigate serious air pollution. However, health benefits attributable to reduced fine-particulate air pollution after the implementation of the APPCAP have not been quantitatively estimated on a PM2.5 constituent-specific and morbidity cause-specific basis. Here we conducted a nationwide case-crossover study based on hospital admission records in 292 Chinese cities during 2013-2017. Compared with 2013, the annual average concentrations of PM2.5 and black carbon (BC) in 2017 decreased by 28.61% and 20.35%, respectively. As a result, the average relative reductions in annual attributable fractions of nine major cause-specific hospital admissions associated with PM2.5 and BC were 30.00% and 21.14%, respectively, among which annual attributable fraction for depression showed the largest reduction. Nationally, cities with higher reductions in PM2.5 and BC were found to have higher absolute reductions in annual hospital admission attributable fractions associated with PM2.5 and BC, and geographic inequality in health benefits still existed. Our study highlights the substantial wide-ranging health benefits of reduced PM2.5 and BC levels following the nationwide implementation of the APPCAP in China.
Spatial distribution of city-specific absolute reductions in annual average concentrations of ambient PM2.5 and BC and average annual hospital admission attributable fractions of nine major cause-specific hospital admissions associated with ambient PM2.5 and BC in 292 Chinese cities of prefecture level or above in 2017 compared with 2013 a,c, Spatial distribution of city-specific absolute reductions in annual average concentrations of ambient PM2.5 (a) and BC (c). b,d, Spatial distribution of city-specific absolute reductions in annual hospital admission attributable fractions associated with ambient PM2.5 (b) and BC (d). City-specific annual attributable fractions were averaged for nine major cause-specific hospital admissions with significant associations with PM2.5 and BC. Absolute reduction in annual attributable fraction was calculated by subtracting the annual attributable fraction in 2017 from the annual attributable fraction in 2013 for each city. For cities with data fewer than 5 years (the number of cities with data fewer than 5 years ranged from 54 for depression to 87 for heart failure), absolute reductions in annual attributable fraction were calculated by subtracting the annual attributable fraction in the last year with data from the annual attributable fraction in the first year with data, and absolute reductions in PM2.5 and BC were calculated by subtracting the annual average concentrations in the last year with data from the annual average concentrations in the first year with data. The annual attributable fractions for cause-specific hospital admissions were calculated based on the exposure-response relationships with a theoretical minimal risk exposure level of 0 μg/m³ as the reference concentration. Negative numbers in absolute reductions represent increases in air pollution concentrations and attributable fractions over the study period. Deeper color presents a larger decline. Cities in gray were not included in the analyses because no hospital admission data were available during the study period.
… 
This content is subject to copyright. Terms and conditions apply.
Nature Medicine | Volume 31 | May 2025 | 1688–1697 1688
nature medicine
Article
https://doi.org/10.1038/s41591-025-03515-y
Hospital admissions attributable to reduced
air pollution due to clean-air policies in China
Huimeng Liu1,2,3,4,17, Jian Lei1,2,3,4,17, Yuewei Liu 5 , Tong Zhu 6,
Kahung Chan 7, Xi Chen 8, Jing Wei9, Furong Deng10, Ge Li1,2,3,4,
Yunxing Jiang1,2,3,4, Lijun Bai1,2,3,4, Kai Wang1,2,3,4, Juan Chen1,2,3,4, Yang Lan1,2,3,4,
Xi Xia 1,2,3,4, Jinxi Wang11, Chen Wei11, Yinxiang Li12, Renjie Chen 13,
Jicheng Gong6, Xiaoli Duan14, Kai Zhang15, Haidong Kan 13, Xiaoming Shi 16,
Xinbiao Guo 10 & Shaowei Wu 1,2,3,4
The Air Pollution Prevention and Control Action Plan (APPCAP) is considered
to be the most stringent air pollution control policy in China implemented
since 2013. This policy is a milestone in China to mitigate serious air
pollution. However, health benets attributable to reduced ne-particulate
air pollution after the implementation of the APPCAP have not been
quantitatively estimated on a PM2.5 constituent-specic and morbidity
cause-specic basis. Here we conducted a nationwide case-crossover study
based on hospital admission records in 292 Chinese cities during 2013-
2017. Compared with 2013, the annual average concentrations of PM2.5 and
black carbon (BC) in 2017 decreased by 28.61% and 20.35%, respectively.
As a result, the average relative reductions in annual attributable fractions
of nine major cause-specic hospital admissions associated with PM2.5 and
BC were 30.00% and 21.14%, respectively, among which annual attributable
fraction for depression showed the largest reduction. Nationally, cities
with higher reductions in PM2.5 and BC were found to have higher absolute
reductions in annual hospital admission attributable fractions associated
with PM2.5 and BC, and geographic inequality in health benets still existed.
Our study highlights the substantial wide-ranging health benets of reduced
PM2.5 and BC levels following the nationwide implementation of the APPCAP
in China.
To date, ambient particulate matter remains a major contributor
to global disease burden. Strong evidence has linked exposure to par-
ticulate matter with an aerodynamic diameter of 2.5 μm or less (PM
2.5
)
pollution to an array of adverse health outcomes, including mortality
or morbidity of respiratory disease
1
, cardiovascular disease (CVD)
2
and
mental health conditions3. In particular, short-term exposure to PM2.5
has been found to trigger the onset of disease episodes such as cardio-
vascular events and psychiatric symptom episodes, which may request
subsequent hospital admissions for intensive treatment
4,5
. Compared
with mortality, morbidity risk measured by hospital admission may
serve as a more sensitive health indicator to capture the acute health
effects of environmental exposures57.
With the rapid economic growth and urban development over
the three decades from the 1980s to the 2000s, China has experienced
severe fine-particulate air pollution8. To mitigate fine-particulate air pol-
lution levels and related health impacts, the State Council of China intro-
duced the Air Pollution Prevention and Control Action Plan (APPCAP)
in 2013. This plan introduced ten specific measures spanning industrial
emissions control, clean energy promotion, vehicle emission standards
improvements, air-quality monitoring systems optimization and tax
Received: 8 July 2024
Accepted: 15 January 2025
Published online: 14 March 2025
Check for updates
A full list of afiliations appears at the end of the paper. e-mail: liuyuewei@mail.sysu.edu.cn; shaowei_wu@xjtu.edu.cn
Content courtesy of Springer Nature, terms of use apply. Rights reserved
... From 2013 to 2021, the PM2.5 concentration decreased from 48.0 µg/m 3 to 27. µg/m 3 , with more significant reductions in key regions such as Beijing-Tianjin-Hebei, th Yangtze River Delta, and the Pearl River Delta [28]. The division of the five major ke control regions in China is primarily based on the severity of pollution and administrativ divisions, facilitating regional joint prevention and control [29]. However, from the per ...
... From 2013 to 2021, the PM 2.5 concentration decreased from 48.0 µg/m 3 to 27.3 µg/m 3 , with more significant reductions in key regions such as Beijing-Tianjin-Hebei, the Yangtze River Delta, and the Pearl River Delta [28]. The division of the five major key control regions in China is primarily based on the severity of pollution and administrative divisions, facilitating regional joint prevention and control [29]. However, from the perspective of health risk prevention and control, this division still has certain limitations. ...
... The delineation of health risk prevention and control areas provides targeted strategies for air pollution management and risk avoidance for both the government and the public. For the government, different types of control areas require specific measures: in coordinated prevention and control areas, the focus should be on the synergistic control of O 3 and PM 2.5 , based on their regional and seasonal correlations [24,25]; in PM 2.5 prevention and control areas, emphasis should be placed on reducing both primary and secondary PM 2.5 emissions, while promoting green transformation in industry and transportation [28]; in O 3 prevention and control areas, controlling VOCs and NOx precursors and updating species-specific emission inventories are key [29]. For the public, raising environmental health awareness is critical [30][31][32]. ...
Article
Full-text available
Air pollution of PM2.5 and O3 is a global health concern. Traditional approaches for identifying air pollution control areas mainly relied on pollutant concentrations, neglecting population distribution and exposure. This study proposes a method to divide these areas from a health risk perspective, comparing their objectivity and rationality with the government-defined key regions. The results show that for PM2.5, the health risk population and average risk rates in the prevention and control areas were 0.993 million (0.1286%), 1.030 million (0.1283%), and 1.023 million (0.1202%) in 2010, 2015, and 2020, significantly higher than in the key areas: 0.778 million (0.1252%), 0.834 million (0.1278%), and 0.825 million (0.1212%). Similarly, for O3, the figures in the prevention and control areas were 0.096 million (0.01228%), 0.095 million (0.01243%), and 0.110 million (0.01316%), also higher than in the key areas: 0.0757 million (0.01218%), 0.078 million (0.01189%), and 0.090 million (0.01315%). Additionally, the Gini coefficients for PM2.5, O3, and overall health risks in the prevention and control areas were lower (0.182, 0.203, 0.284) compared to those in the key areas (0.207, 0.216, 0.292). This study provides a method for defining air pollution control regions based on health risks, offering significant insights for pollution zoning and prevention strategies
Article
Full-text available
Air pollution imposes a substantial economic burden globally, with estimated annual losses exceeding 8.1trillionduetohealthcarecosts,lostproductivity,infrastructuredegradation,andagriculturaldamage.Thisreviewassessestheeconomiceffectivenessofadvancedairpollutioncontroltechnologieswithinthebroadercontextofsustainableenergytransitions.Throughcomparativelifecyclecostbenefitanalyses,weevaluatethefinancialviability,energyefficiency,andpolicyrelevanceofinnovationssuchascarboncaptureandstorage(CCS),AIdrivenemissionsmonitoring,andnanotechnologyenhancedfiltration.Amongthetechnologiesassessed,CCSpresentsthemostsignificantcapitalexpenditure(upto8.1 trillion due to healthcare costs, lost productivity, infrastructure degradation, and agricultural damage. This review assesses the economic effectiveness of advanced air pollution control technologies within the broader context of sustainable energy transitions. Through comparative life-cycle cost-benefit analyses, we evaluate the financial viability, energy efficiency, and policy relevance of innovations such as carbon capture and storage (CCS), AI-driven emissions monitoring, and nanotechnology-enhanced filtration. Among the technologies assessed, CCS presents the most significant capital expenditure (up to 500 million per facility) but offers long-term returns through carbon credits and enhanced oil recovery, yielding up to 3040ineconomicbenefitsforevery30–40 in economic benefits for every 1 invested. AI-based monitoring systems demonstrate strong economic efficiency by reducing energy consumption in industrial operations by up to 15% and improving regulatory compliance at a larger scale. Nanotechnology-enabled filters provide high pollutant capture efficiency and reduce operational resistance, yet face scalability and end-of-life challenges. Additionally, emerging technologies such as bioengineered filters offer promise for low-resource settings but require further economic validation. The integration of these technologies with renewable energy systems, such as hydrogen-powered pollution control units and solar-driven filtration, further amplifies their environmental and economic benefits. By aligning air pollution mitigation with climate and energy goals, this review highlights a pathway for policymakers and industries to achieve both economic resilience and environmental sustainability. The findings underscore that, while upfront costs may be high, strategic investments in advanced pollution control deliver substantial long-term returns across sectors.
Article
Full-text available
Previous studies have shown that exposure to black carbon (BC, a tracer of traffic-related air pollution) and psychosocial stress are both associated with adverse cardiac effects, but whether psychosocial stress could modify the cardiac effects of BC is unclear. To investigate the potential modifying effect of psychosocial stress on the associations between acute exposure to BC and typical cardiac health variables, real-time personal 24 h measurements were conducted in a repeated-measure study among adults with elevated blood pressure (high-risk group) and a panel study among normal adults (low-risk group) in China. Measured cardiac health variables included ST-segment depression events, heart rate, and heart rate variability (HRV) variables. Perceived Stress Scale, State Anxiety Inventory and Self-rating Depression Scale were used to assess the recent psychosocial stress status of the participants, and a composite stress index was established based on these scales. Generalized linear mixed-effects model was used to analyze the associations between BC exposure and cardiac health variables and potential effect modification by psychosocial stress. A total of 97 24 h measurements among 97 participants in the repeated-measure study and 202 24 h measurements among 87 participants in the panel study were included in the final analysis. Acute BC exposure was significantly associated with increased ST-segment depression events and heart rate and decreases in HRV in both studies. The marginal effects of acute BC exposure on most cardiac health variables generally tended to be amplified under higher vs low levels of psychosocial stress in both studies, with the composite stress index apparently modifying the associations of BC exposure with most ST-segment depression events and HRV variables. These findings suggest that psychosocial stress may increase the participants’ cardiac susceptibility to BC exposure, which could be helpful for the identification of susceptible individuals in the context of traffic-related air pollution.
Article
Full-text available
Clean air actions (CAAs) in China have been linked to considerable benefits in public health. However, whether the beneficial effects of CAAs are equally distributed geographically is unknown. Using high-resolution maps of the distributions of major air pollutants (fine particulate matter [PM2.5] and ozone [O3]) and population, we aimed to track spatiotemporal changes in health impacts from, and geographic inequality embedded in the reduced exposures to PM2.5 and O3, from 2013 to 2020. We used a method established by the Global of Burden Diseases Study. By analyzing the changes in loss of life expectancy (LLE) attributable to PM2.5 and O3, we calculated the gain of life expectancy (GLE) to quantify the health benefits of the air-quality improvement. Finally, we assessed the geographic inequality embedded in the GLE using the Gini Index (GI). Based on risk assessments of PM2.5 and O3, during the first stage of CAAs (2013 to 2017), the mean GLE was 1.87 months. Half of the sum of the GLE was disproportionally distributed in about one quarter of the population exposed (GI 0.44). During the second stage of CAAs (2017 to 2020), the mean GLE increased to 3.94 months and geographic inequality decreased (GI 0.18). According to our assessments, CAAs were enhanced, from the first to second stages, in terms of not only preventing premature mortality but also ameliorating health inequalities. The enhancements were related to increased sensitivity to the health effects of air pollution and synergic control of PM2.5 and O3 levels. Our findings will contribute to optimize future CAAs.
Article
Full-text available
Based on the PM2.5 concentration in the autumn and winter of 2015-2019, the characteristics of urban air pollution in the eastern monsoon region of China were discussed. The spatial distribution and interregional influence of fine particle pollution under different synoptic weather and topography in the eastern monsoon region of China were illustrated. According to synoptic systems, regional PM2.5 pollution episodes were classified into three categories, including Uniform Pressure field (UP, 60.00%), Pre-High Pressure (PreHP, 30.91%) and Inverted-Trough (IT, 9.09%). The K-Means algorithm combined with the HYSPLIT backward trajectory clustering analysis indicated four clusters under UP controlled, and under weak pressure field was responsible for the elevation of PM2.5 concentration, where the Beijing-Tianjin-Hebei and its surrounding areas were the most polluted region. For PreHP, four clusters eased after cold front. For IT, three clusters were ascertained, and the severe PM2.5 pollution area was in the central and southern of the North China Plain. This study provided a scientific basis for the joint prevention of PM2.5 pollution based on topographic and meteorological characteristics in Eastern China.
Article
Full-text available
Background: Evidence on the associations between long-term exposure to multiple air pollutants and cardiopulmonary mortality is limited, especially for developing regions with higher pollutant levels. We aimed to characterise the individual and joint (multi-pollutant) associations of long-term exposure to air pollutants with cardiopulmonary mortality, and to identify air pollutant that primarily contributes to the mortality risk. Methods: We followed 37,442 participants with a mean age of 43.5 years in four cities in northern China (Tianjin, Shenyang, Taiyuan, and Rizhao) from January 1998 to December 2019. Annual particulate matter (PM) with diameters ≤2.5 μm (PM2.5), ≤10 μm (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2) were estimated using daily average values from satellite-derived machine learning models and monitoring stations. Time-varying Cox proportional hazards model was used to evaluate the individual association between air pollutants and mortality from non-accidental causes, cardiovascular diseases (CVDs), non-malignant respiratory diseases (RDs) and lung cancer, accounting for demographic and socioeconomic factors. Effect modifications by age, sex, income and education level were also examined. Quantile-based g-Computation integrated with time-to-event data was additionally applied to evaluate the co-effects and the relative weight of contributions for air pollutants. Findings: During 785,807 person-years of follow-up, 5812 (15.5%) died from non-accidental causes, among which 2932 (7.8%) were from all CVDs, 479 (1.3%) from non-malignant RDs, and 552 (1.4%) from lung cancer. Long-term exposure to PM10 (mean [baseline]: 136.5 μg/m3), PM2.5 (mean [baseline]: 70.2 μg/m3), SO2 (mean [baseline]: 113.0 μg/m3) and NO2 (mean [baseline]: 39.2 μg/m3) were adversely and consistently associated with all mortality outcomes. A 10 μg/m3 increase in PM2.5 was associated with higher mortality from non-accidental causes (hazard ratio 1.20; 95% confidence interval 1.17-1.23), CVDs (1.23; 1.19-1.28), non-malignant RDs (1.37; 1.25-1.49) and lung cancer (1.14; 1.05-1.23). A monotonically increasing curve with linear or supra-linear shape with no evidence of a threshold was observed for the exposure-response relationship of mortality with individual or joint exposure to air pollutants. PM2.5 consistently contributed most to the elevated mortality risks related to air pollutant mixture, followed by SO2 or PM10. Interpretation: There was a strong and positive association of long-term individual and joint exposure to PM10, PM2.5, SO2, and NO2 with mortalities from non-accidental causes, CVDs, non-malignant RDs and lung cancer in high-exposure settings, with PM2.5 potentially being the main contributor. The shapes of associations were consistent with a linear or supra-linear exposure-response relationship, with no lower threshold observed within the range of concentrations in this study. Funding: National Key Research and Development Program of China, the China Scholarship Council, the National Natural Science Foundation of China, Natural Science Foundation of Guangdong Province.
Article
A broader approach to assessing the burden of disease from air pollution is required
Article
Background: Ultrafine particles, including black carbon (BC), can reach the systemic circulation and therefore may distribute to distant organs upon inhalation. The kidneys may be particularly vulnerable to the adverse effects of BC exposure due to their filtration function. Objectives: We hypothesized that BC particles reach the kidneys via the systemic circulation, where the particles may reside in structural components of kidney tissue and impair kidney function. Methods: In kidney biopsies from 25 transplant patients, we visualized BC particles using white light generation under femtosecond-pulsed illumination. The presence of urinary kidney injury molecule-1 (KIM-1) and cystatin c (CysC) were evaluated with ELISA. We assessed the association between internal and external exposure matrices and urinary biomarkers using Pearson correlation and linear regression models. Results: BC particles could be identified in all biopsy samples with a geometric mean (5th, 95th percentile) of 1.80 × 103 (3.65 × 102, 7.50 × 103) particles/mm3 kidney tissue, predominantly observed in the interstitium (100 %) and tubules (80 %), followed by the blood vessels and capillaries (40 %), and the glomerulus (24 %). Independent from covariates and potential confounders, we found that each 10 % higher tissue BC load resulted in 8.24 % (p = 0.03) higher urinary KIM-1. In addition, residential proximity to a major road was inversely associated with urinary CysC (+10 % distance: −4.68 %; p = 0.01) and KIM-1 (+10 % distance: −3.99 %; p
Article
Background: The associations between fine and coarse particulate matter (PM2.5 and PM2.5-10) air pollution and hospital admissions for full-spectrum respiratory diseases were rarely investigated, especially for age-specific associations. We aim to estimate the age-specific associations of short-term exposures to PM2.5 and PM2.5-10 with hospital admissions for full-spectrum respiratory diseases in China. Methods: We conducted an individual-level case-crossover study based on a nationwide hospital-based registry including 153 hospitals across 20 provincial regions in China in 2013-20. We applied conditional logistic regression models and distributed lag models to estimate the exposure- and lag-response associations. Results: A total of 1 399 955 hospital admission records for various respiratory diseases were identified. The associations of PM2.5 and PM2.5-10 with total respiratory hospitalizations lasted for 4 days, and an interquartile range increase in PM2.5 (34.5 μg/m3) and PM2.5-10 (26.0 μg/m3) was associated with 1.73% [95% confidence interval (95% CI): 1.34%, 2.12%)] and 1.70% (95% CI: 1.31%, 2.10%) increases, respectively, in total respiratory hospitalizations over lag 0-4 days. Acute respiratory infections (i.e. pneumonia, bronchitis and bronchiolitis) were consistently associated with PM2.5 or PM2.5-10 exposure across different age groups. We found the disease spectrum varied by age, including rarely reported findings (i.e. acute laryngitis and tracheitis, and influenza) among children and well-established associations (i.e. chronic obstructive pulmonary disease, asthma, acute bronchitis and emphysema) among older populations. Besides, the associations were stronger in females, children and older populations. Conclusions: This nationwide case-crossover study provides robust evidence that short-term exposure to both PM2.5 and PM2.5-10 was associated with increased hospital admissions for a wide range of respiratory diseases, and the spectra of respiratory diseases varied by age. Females, children and older populations were more susceptible.
Article
Fine particulate matter (PM2.5) chemical composition has strong and diverse impacts on the planetary environment, climate, and health. These effects are still not well understood due to limited surface observations and uncertainties in chemical model simulations. We developed a four-dimensional spatiotemporal deep forest (4D-STDF) model to estimate daily PM2.5 chemical composition at a spatial resolution of 1 km in China since 2000 by integrating measurements of PM2.5 species from a high-density observation network, satellite PM2.5 retrievals, atmospheric reanalyses, and model simulations. Cross-validation results illustrate the reliability of sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and chloride (Cl-) estimates, with high coefficients of determination (CV-R2) with ground-based observations of 0.74, 0.75, 0.71, and 0.66, and average root-mean-square errors (RMSE) of 6.0, 6.6, 4.3, and 2.3 μg/m3, respectively. The three components of secondary inorganic aerosols (SIAs) account for 21% (SO42-), 20% (NO3-), and 14% (NH4+) of the total PM2.5 mass in eastern China; we observed significant reductions in the mass of inorganic components by 40-43% between 2013 and 2020, slowing down since 2018. Comparatively, the ratio of SIA to PM2.5 increased by 7% across eastern China except in Beijing and nearby areas, accelerating in recent years. SO42- has been the dominant SIA component in eastern China, although it was surpassed by NO3- in some areas, e.g., Beijing-Tianjin-Hebei region since 2016. SIA, accounting for nearly half (∼46%) of the PM2.5 mass, drove the explosive formation of winter haze episodes in the North China Plain. A sharp decline in SIA concentrations and an increase in SIA-to-PM2.5 ratios during the COVID-19 lockdown were also revealed, reflecting the enhanced atmospheric oxidation capacity and formation of secondary particles.
Article
Aims: The available literature on morbidity risk of cardiovascular diseases associated with ambient ozone pollution is still limited. This study examined the potential acute effects of exposure to ambient ozone pollution on hospital admissions of cardiovascular events in China. Methods and results: A two-stage multi-city time-series study approach was used to explore the associations of exposure to ambient ozone with daily hospital admissions (n = 6 444 441) for cardiovascular events in 70 Chinese cities of prefecture-level or above during 2015-17. A 10 μg/m3 increment in 2-day average daily 8 h maximum ozone concentrations was associated with admission risk increases of 0.46% [95% confidence interval (CI): 0.28%, 0.64%] in coronary heart disease, 0.45% (95% CI: 0.13%, 0.77%) in angina pectoris, 0.75% (95% CI: 0.38%, 1.13%) in acute myocardial infarction (AMI), 0.70% (95% CI: 0.41%, 1.00%) in acute coronary syndrome, 0.50% (95% CI: 0.24%, 0.77%) in heart failure, 0.40% (95% CI: 0.23%, 0.58%) in stroke and 0.41% (95% CI: 0.22%, 0.60%) in ischemic stroke, respectively. The excess admission risks for these cardiovascular events associated with high ozone pollution days (with 2-day average 8-h maximum concentrations ≥100 µg/m3 vs. < 70 µg/m3) ranged from 3.38% (95% CI: 1.73%, 5.06%) for stroke to 6.52% (95% CI: 2.92%, 10.24%) for AMI. Conclusion: Ambient ozone was associated with increased hospital admission risk for cardiovascular events. Greater admission risks for cardiovascular events were observed under high ozone pollution days. These results provide evidence for the harmful cardiovascular effects of ambient ozone and call for special attention on the control of high ozone pollution.