Population-weighted and area-weighted ambient PM2.5 and O3 concentrations in China from 2015 to 2024
- 1Department of Emergency, The Affiliated Panyu Central Hospital of Guangzhou Medical University
- 2The Affiliated Guangdong Second Provincial General Hospital of Jinan University
- 3The Second People’s Hospital of Panyu District
Abstract
Background: National air-pollution summaries can mask the concentrations experienced by populations across the locations where they live. We quantified annual population-weighted (PW) and area-weighted (AW) ambient PM 2.5 and ground-level O ₃ metrics in China from 2015 to 2024.
Methods: In this repeated-year ecological geospatial analysis, annual ChinaHighAirPollutants (CHAP) PM 2.5 Version 4 and yearly maximum daily 8-h average (MDA8) O ₃ Version 3 rasters were linked to WorldPop Global2 R2025A population-count rasters. Population-weighted concentrations were compared with spherical-cell-area-weighted means calculated across all valid CHAP cells. National linear trends included 95% confidence intervals (CIs); 0.2° spatial slopes were descriptive, with 0.1° and 0.25° sensitivity analyses.
Results: Population-weighted PM 2.5 declined from 53.06 to 31.25 μg/m ³ , while its area-weighted mean declined from 42.69 to 24.83 μg/m ³ . Population-weighted yearly MDA8 O ₃ increased from 77.06 to 96.75 μg/m ³ , while the area-weighted mean increased from 73.38 to 96.29 μg/m ³ . Population-weighted national slopes were −2.51 μg/m ³ /year (95% CI, −3.16 to −1.87) for PM 2.5 and 1.99 μg/m ³ /year (95% CI, 1.19 to 2.79) for O ₃ . Across valid 0.2° blocks, median descriptive slopes were −1.82 and 1.99 μg/m ³ /year, respectively, and spatial summaries were stable at alternative aggregation resolutions.
Conclusion: PM 2.5 and O ₃ showed opposing national and spatial patterns. Population weighting materially changed national summaries, particularly for PM 2.5 , supporting its use alongside area-weighted estimates in environmental public-health surveillance.
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BibTeX
@article{mai2026populationweighted,
title = {{Population-weighted and area-weighted ambient PM2.5 and O3 concentrations in China from 2015 to 2024}},
author = {Xiaowei Mai and Zhenyu Liang and Lin Li and Debo Xu and Yonghua Chen and Junyi Xia},
journal = {Frontiers in Public Health},
year = {2026},
month = nov,
doi = {10.3389/fpubh.2026.2000035},
url = {https://www.frontiersin.org/articles/10.3389/fpubh.2026.2000035/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Population-weighted and area-weighted ambient PM2.5 and O3 concentrations in China from 2015 to 2024
AU - Xiaowei Mai
AU - Zhenyu Liang
AU - Lin Li
AU - Debo Xu
AU - Yonghua Chen
AU - Junyi Xia
PY - 2026
DA - 2026/11/04
JO - Frontiers in Public Health
DO - 10.3389/fpubh.2026.2000035
UR - https://www.frontiersin.org/articles/10.3389/fpubh.2026.2000035/full
AB - Background: National air-pollution summaries can mask the concentrations experienced by populations across the locations where they live. We quantified annual population-weighted (PW) and area-weighted (AW) ambient PM 2.5 and ground-level O ₃ metrics in China from 2015 to 2024. Methods: In this repeated-year ecological geospatial analysis, annual ChinaHighAirPollutants (CHAP) PM 2.5 Version 4 and yearly maximum daily 8-h average (MDA8) O ₃ Version 3 rasters were linked to WorldPop Global2 R2025A population-count rasters. Population-weighted concentrations were compared with spherical-cell-area-weighted means calculated across all valid CHAP cells. National linear trends included 95% confidence intervals (CIs); 0.2° spatial slopes were descriptive, with 0.1° and 0.25° sensitivity analyses. Results: Population-weighted PM 2.5 declined from 53.06 to 31.25 μg/m ³ , while its area-weighted mean declined from 42.69 to 24.83 μg/m ³ . Population-weighted yearly MDA8 O ₃ increased from 77.06 to 96.75 μg/m ³ , while the area-weighted mean increased from 73.38 to 96.29 μg/m ³ . Population-weighted national slopes were −2.51 μg/m ³ /year (95% CI, −3.16 to −1.87) for PM 2.5 and 1.99 μg/m ³ /year (95% CI, 1.19 to 2.79) for O ₃ . Across valid 0.2° blocks, median descriptive slopes were −1.82 and 1.99 μg/m ³ /year, respectively, and spatial summaries were stable at alternative aggregation resolutions. Conclusion: PM 2.5 and O ₃ showed opposing national and spatial patterns. Population weighting materially changed national summaries, particularly for PM 2.5 , supporting its use alongside area-weighted estimates in environmental public-health surveillance.
SN - 2296-2565
ER -