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.

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.

Ecological resilience is a natural barrier for urban systems to cope with a series of problems brought by climate change and urbanization, which can also enhance regional ecological security. To improve the ecological resilience of Chongming Island, we explore the interrelationship between the government's construction orientations and its ecological resilience. Further evaluation reference for near-continental urbanized islands are provided. In this paper, the ecological resilience evaluation system, based on the landscape pattern-process-PSR (Pressure-State-Response) model, is constructed to evaluate the ecological resilience of Chongming Island by integrating landscape background quality, pressure factors, and anthropogenic response. The results show that Chongming's resilience score is divided into two stages. The first stage is the resilience weakening period from 1990 to 1999, except for a little increase from 0.3699 to 0.3979 between1990 and 1991, the left resilience score between 1991 to 1999 kept declining to the lowest0.2382 in 1999.The second stage is the resilience-building phase between 2000 and 2020, during which Chongming's resilience increased rapidly, with stagnation between 2011 and 2015, and high growth resumed after 2015. The findings suggest that the changes in ecological resilience in Chongming are closely related to government’s planning orientations.