Background: It is true that Chronic obstructive pulmonary disease (COPD) will increase social burden, especially in developing countries. Urban-rural differences in the lagged effects of PM2.5 and PM10 on COPD mortality remain unclear, in Chongqing, China. Methods: In this study, a distributed lag non-linear model (DLNMs) was established to describe the urban-rural differences in the lagged effects of PM2.5, PM10 and COPD mortality in Chongqing, using 312,917 deaths between 2015 and 2020. Results: According to the DLNMs results, COPD mortality in Chongqing increases with increasing PM2.5 and PM10 concentrations, and the relative risk (RR) of the overall 7-day cumulative effect is higher in rural areas than in urban areas. High values of RR in urban areas occurred at the beginning of exposure (Lag 0 ~ Lag 1). High values of RR in rural areas occur mainly during Lag 1 to Lag 2 and Lag 6 to Lag 7. Conclusion: Exposure to PM2.5 and PM10 is associated with an increased risk of COPD mortality in Chongqing, China. COPD mortality in urban areas has a high risk of increase in the initial phase of PM2.5 and PM10 exposure. There is a stronger lagging effect at high concentrations of PM2.5 and PM10 exposure in rural areas, which may further exacerbate inequalities in levels of health and urbanization.

The Green View Index (GVI) is utilized to evaluate urban street value and ecosystem services and to gauge public perceptions of street greening. This study investigates the spatial heterogeneity of the GVI and its influencing factors in Yuzhong District, Chongqing, a mountainous city in China. Deep learning algorithms were employed to calculate the green visibility of street view images, and Geographic Weighted Regression (GWR) and the Optimal Parameter-Based Geodetector (OPGD) were utilized to analyze the relationships between GVI and factors such as road physical attributes, the Normalized Difference Vegetation Index (NDVI), and topographic features. The results indicate that: (1) In Yuzhong District, 58.9% of streets have a GVI within a low to moderate range, suggesting room for improvement. Higher GVI levels are generally associated with elevated Digital Elevation Models (DEM), while slope, aspect, and terrain undulation have relatively minor overall impacts on GVI. (2) The GVI is highest in the western regions and lowest in the eastern regions, with streets along the riversides exhibiting lower GVI levels. (3) GWR analysis reveals that road type and NDVI significantly influence the GVI. Higher DEM values promote increased GVI, whereas high road density suppresses it. (4) The interaction between influencing factors drives the differentiated distribution of GVI within the study area. The interaction effects between Road type, NDVI, and DEM are particularly notable among these.

Background: There are regional differences in the effect of green space on mortality of Chronic obstructive pulmonary disease (COPD). We conduct an ecological study, using the administrative divisions of Chongqing townships in China as the basic unit, to investigate the association between COPD mortality and green space based on data of 313,013 COPD deaths in Chongqing from 2012 to 2020. Green space is defined by Fractional vegetation cover (FVC), which is further calculated based on the normalised vegetation index (NDVI) from satellite remote sensing imagery maps. Methods: After processing the data, the non-linear relationship between green space and COPD mortality is revealed by generalised additive models; the spatial differences between green space and COPD mortality is described by geographically weighted regression models; and finally, the interpretive power and interaction of each factor on the spatial distribution of COPD mortality is examined by a geographic probe. Results: The results show that the FVC local regression coefficients ranged from − 0.0397 to 0.0478, 63.0% of the regions in Chongqing have a positive correlation between green space and COPD mortality while 37.0% of the regions mainly in the northeast and west have a negative correlation. The interpretive power of the FVC factor on the spatial distribution of COPD mortality is 0.08. Conclusions: Green space may be a potential risk factor for increased COPD mortality in some regions of Chongqing. This study is the first to reveal the relationship between COPD mortality and green space in Chongqing at the township scale, providing a basis for public health policy formulation in Chongqing.

Low temperatures are an important risk factor for chronic obstructive pulmonary disease (COPD). However, trends and projections of the global burden of COPD at low temperatures are unclear. Based on data from the 2021 Global Burden of Disease Study (GBD), this study assessed trends in the global and regional burden of death and disability-adjusted life years (DALYs) due to COPD from 1990 to 2021, and identified patterns of change in different regions. A Bayesian Age-Period-cohort (BAPC) model was used to predict the burden of COPD over the next 20 years. Although the number of COPD deaths worldwide in 2021 increased from 242,170 in 1990 to 300,849, and the number of DALYs increased from 4,749,734 to 4,981,981, the age-standardized deaths rate decreased from 7.04 to 3.69 per 100,000, and the DALYs rate decreased from 126.69 to 59.22 per 100,000. Up to 2021, men consistently bore a higher burden than women, though their age-standardized deaths rate declined more sharply (54.2% vs. 39.2%). COPD burden increased notably after age 45, with those aged 65 and older contributing most to the total and showing the steepest rise. By SDI level, middle and middle-high SDI regions had the highest burden but saw the fastest declines, while low and low-middle SDI areas carried heavier burdens with slower reductions. High SDI regions maintained low and stable burden levels. BAPC projections suggest a continued but slower decline in COPD mortality linked to low temperature by 2041, with a projected drop of 1.39 per 100,000, less than the 3.35 per 100,000 reduction observed from 1990 to 2021. Global age-standardized mortality and DALYs for COPD at risk of low temperatures have declined over the past 30 years, with absolute burden numbers, BAPC predicting a slower rate of decline in the future, and persistent cross-country health inequalities. More precise interventions should be developed to target the resistance to low-temperature risk in older age groups and areas with low SDI.

Air pollution can lead to the elevated incidence of various respiratory diseases, seriously endangering the health of urban residents. To better comprehend the association between urban air pollution and respiratory disease incidence, this study focused on Xinxiang City, a typical industrial city in the North China Plain, as the research object. By analyzing monthly air pollution index concentrations from 2018 to 2021 and confirmed cases of respiratory diseases, and incorporating meteorological factors as reference points, we conducted a correlation analysis between disease data and pollutant concentrations. We then constructed a Poisson regression model to obtain maximum likelihood estimates, which were used to predict the quantitative relationship between the incidence of respiratory diseases and air pollution indicators. The results showed that an increase of 1 μg/m³ in the average mass concentration of PM_2.5, PM₁₀, NO_2, and SO₂ in ambient air was associated with an elevated incidence of respiratory diseases by 0.2–1.4%, 0.7–1.6%, 3.7–8.2%, and 0.5–2.3%, respectively; meanwhile, a monthly mean mass concentration of CO increased by 1 mg/m³ led to a rise in pulmonary tuberculosis incidence by 2.9%. Additionally, based on health risk data following exposure to air pollution in Xinxiang City, it was confirmed that the impact of respiratory diseases as measured by the air quality composite index was more applicable than the single pollution index. Furthermore, there was a significant association between air pollution and the incidence of respiratory diseases.

Background: The timeliness of treatment for out-of-hospital cardiac arrest (OHCA) is critical for patient survival. Automated External Defibrillators (AEDs) are a proven effective intervention, yet China’s rapidly developing Public Access Defibrillation (PAD) program may be accompanied by significant spatial inequities in AED distribution. Methods: This study developed a comprehensive multi-dimensional evaluation model to assess the spatial equity of AED allocation in four first-tier Chinese cities: Beijing, Shanghai, Guangzhou, and Shenzhen. The model integrated four dimensions: resource allocation (supply–demand ratio), spatial coverage (service coverage index), opportunity accessibility (accessibility index via an enhanced Gaussian two-step floating catchment area method), and spatial distribution (Gini coefficient). These dimensions were aggregated into a Comprehensive Equity Index (CEI) using the Entropy Weight Method (EWM). Leveraging high-resolution gridded population data and precise AED locations, our analysis captures fine-scale spatial variations often obscured in aggregate statistics. Furthermore, to uncover the spatially heterogeneous drivers of equity, we employed an integrated Principal Component Analysis and Geographically Weighted Regression (PCA-GWR) framework to analyze socioeconomic and urban environmental factors. Results: The results indicate that: (1) Overall comprehensive equity was low across all cities (mean CEI < 0.3). Shenzhen exhibited the highest equity (mean CEI: 0.252), followed by Beijing (0.207), with Shanghai and Guangzhou lagging. (2) A significant “core-periphery” disparity was observed in all cities, with core districts showing markedly higher equity than suburban districts, a gap particularly pronounced in Beijing and Shanghai. (3) The PCA-GWR analysis revealed pronounced spatial heterogeneity in the associations between external factors and AED equity. Degree of urbanization showed a generally positive association, which was consistently weaker in urban cores. Public service facility provision exhibited inconsistent (often negative) associations, while the wealth-population density trade-off demonstrated marked city-specific variation. Conclusions: This study provides a systematic, multidimensional assessment of AED allocation equity in major Chinese cities. By employing a spatially nuanced PCA-GWR framework, it reveals that equity is shaped by complex, location-specific interactions of urban development, service provision, and socioeconomic structure. The findings underscore the necessity for spatially differentiated policy interventions within China’s PAD program to achieve more equitable and efficient deployment of these lifesaving resources.