BACKGROUND: Despite evidence linking fine particulate matter (PM2.5) to cardiometabolic multimorbidity (CMM), the impact of its components remains unclear. Socioeconomic status (SES) and regional disparities may confound their association. We aim to evaluate the associations between PM2.5 components and CMM and explore how socioeconomic status and regional disparities affect these relationships.
METHODS: We recruited 108,941 participants aged 35-76 years from ten cities in eastern China. Individual exposure was assessed using Tracking Air Pollution in China (TAP) data, including PM2.5 and five components: ammonium (NH4+), black carbon (BC), nitrates (NO3-), organic matter (OM), and sulfates (SO42-). Generalized linear models and quantile g-computation models were employed to quantify the effects of PM2.5 components on CMM and to identify key components. Stratified analyses were performed to investigate the modifying effect of SES and regional disparities.
RESULTS: For each increase in interquartile range (IQR), BC (odds ratio [OR] 1.37, 95 % CI 1.29-1.47), OM (1.38, 1.29-1.48), NH4+ (1.31, 1.21-1.40), NO3- (1.34, 1.25-1.44), and SO42- (1.28, 1.20-1.38) were positively associated with CMM. Joint exposure to five components was significantly positively associated with CMM (OR: 1.27, 95 % CI: 1.21-1.33), with SO42- having the highest estimated weight, followed by NO3- and BC. These associations were stronger for participants from low socio-economic status and poor regions.
CONCLUSIONS: In summary, we found a stronger hazard effect of PM2.5 and its components on CMM, compared to those suffering from CMDs, particularly among participants with low socioeconomic status and in poor regions. SO42- may be a primary contributor to the association between PM2.5 components and CMM. These findings underscore the importance of prioritizing CMM and targeting SO42-related pollution sources in health policies, particularly amid China\'s aging population, reducing environmental health inequalities is critical.

Most studies analyzing the effects of air pollution on disadvantaged populations use ground air quality measurements. However, ground stations are generally limited, with nearly 40% of countries having no official PM2.5 stations, not allowing air quality analysis for a significantly large share of the world\'s population. Furthermore, limited studies analyze community data from a geodemographic perspective, in other words, to delineate the sociodemographic profiles and geographically locate the socioeconomic groups more exposed to ambient air pollution. Therefore, a significant question arises: How can we trace vulnerable communities to air pollution in areas lacking air-quality ground data? Here, we propose a novel methodology to respond to this question. We use NO2, SO2, CO, and HCHO tropospheric column air-quality data from Sentinel-5P, a satellite that quantifies concentrations of atmospheric species from space operationally. We integrate them with census and environmental data and apply the local fuzzy geographically weighted clustering spatial machine learning method for segmentation analysis. Our findings for Bali, Indonesia, provide quantitative evidence for the benefits of this methodology in tracing and delineating the profiles of the communities most exposed to air pollution. For example, results show that communities with highly disadvantaged populations, such as unemployed (over 27.8%), low educated (over 27.9%), and children (over 22.1%) (mainly located around Bali\'s south and north coast touristic areas), exhibit very high values (over the 75th quartile) across the pollutants studied. The proposed method is reproducible easily, quickly, and at low cost, as it is based on freely available satellite data and not on costly ground station measurements. This will hopefully assist decision-makers in tracing the most vulnerable subpopulations, even in areas with inadequate air-quality monitoring networks, thus allowing local governments around the globe (even those that are financially weak) to achieve environmental justice and their sustainable development goals.

Air pollution poses a critical public health threat around many megacities but in an uneven manner. Conventional models are limited to depict the highly spatial- and time-varying patterns of ambient pollutant exposures at the community scale for megacities. Here, we developed a machine-learning approach that leverages the dynamic traffic profiles to continuously estimate community-level year-long air pollutant concentrations in Los Angeles, U.S. We found the introduction of real-world dynamic traffic data significantly improved the spatial fidelity of nitrogen dioxide (NO2), maximum daily 8-h average ozone (MDA8 O3), and fine particulate matter (PM2.5) simulations by 47%, 4%, and 15%, respectively. We successfully captured PM2.5 levels exceeding limits due to heavy traffic activities and providing an \"out-of-limit map\" tool to identify exposure disparities within highly polluted communities. In contrast, the model without real-world dynamic traffic data lacks the ability to capture the traffic-induced exposure disparities and significantly underestimate residents\' exposure to PM2.5. The underestimations are more severe for disadvantaged communities such as black and low-income groups, showing the significance of incorporating real-time traffic data in exposure disparity assessment.

The conservation management of natural ecosystems in China has significantly improved in recent decades, resulting in the effective protection of wildlife and the restoration of habitats. With the rapid growth in wildlife populations and corresponding range expansions, incidents of human-wildlife conflict have notably increased across China. However, only a few studies have paid adequate attention to wildlife damage management and compensation. In our review, we focus on the foremost mitigation measure to combat human-wildlife conflict, i.e., compensation for damage caused by wildlife. We conducted a questionnaire survey and an in-depth review of the literature across 19 Chinese provinces and autonomous regions, resulting in a total of 78 relevant sources. We first introduce the concept of wildlife damage compensation in China, followed by a review of Chinese legislation and policies regarding wildlife damage compensation. We compiled a comprehensive list of nuisance species, and we showcase four case studies in which we exemplarily describe the current situation of wildlife damage compensation. We reflect on difficulties and challenges such as delayed damage assessments or compensation quotas that do not correspond to current market prices. Since local legislation is often insufficient or completely absent, we make suggestions on how to improve existing policies and compensation mechanisms.

The escalating contradiction between global urban development and thermal environments has become increasingly apparent, underscoring the imperative to address social inequality in heat exposure and advocate for environmental justice (EJ) in the pursuit of sustainable urban development. To bridge the research gap in this domain, a comprehensive study was conducted to examine the correlation mechanism linking the thermal environment with the socioeconomic status (SES) of Chinese cities, employing Hangzhou as a representative case-a pivotal city among China\'s \"four fire stoves\". The investigation involved analyzing the spatial distribution pattern of diurnal Land Surface Temperature (LST) during the summer months spanning 2016 to 2018 (July to September). For SES characterization, a holistic indicator was established. Community-level LST variables were derived from LST surfaces obtained through the Terra and Aqua satellite MODIS sensors, with the community serving as the fundamental unit of analysis. The relationship between SES and LST was explored using random forest regression (RF), eXtreme Gradient Boosting (XGBoost), and support vector regression (SVR) to assess socioeconomic inequality in urban heat. The findings reveal that (1) RF exhibits the highest fitting accuracy and adeptly elucidates the nonlinear relationship and marginal effects between LST variables and SES. (2) Community SES in the Hangzhou metropolitan area exhibits spatial clustering. (3) Residents of low and middle SES communities experience heightened heat inequality. (4) A complex nonlinear relationship exists between daytime and nighttime LST and SES, with significant social disparities in urban heat within specific temperature thresholds. When deciding on measures to advance thermal environmental justice, it is crucial to prioritize both relatively disadvantaged groups and specific temperature intervals. This study departs from conventional approaches, exploring the nonlinear relationship between SES and urban heat at a fine scale, thereby assisting urban planners in developing effective strategies.

Ensuring equitable access to green spaces in urban built-up areas is not only vital for fostering environmental justice but also aligns with the United Nations Sustainable Development Goals (SDGs). However, there is a noticeable gap in the current body of research regarding the role of small urban green spaces, especially their multifunctionality from an ecosystem services perspective. Taking the urban built-up area of Harbin as an example, this study first applied the Analytic Hierarchy Process to classify the supply and demand of green space into three types. Then, the article further analyzes the potential functional positioning of the newly added green spaces, including ecological and social functions, using Minimum Cumulative Resistance and Point of Interest. Finally, multi-criteria decision models are used to explore the priority and functional positioning of green space and construct a multi-functional and highly-efficient small urban green space network. The results indicate a significant imbalance in green space supply and demand, with severe and medium mismatch areas accounting for 30.17 % and 48.50 %, respectively. By assessing the multifunctionality of small green spaces, we propose guidelines that include five types of areas: Concentrated Development (85.85 km2, 16.94 %), Backup Development (70.74 km2, 14.31 %), Maintenance (304.49 km2, 61.51 %), Protection (14.94 km2, 3.02 %), and Optimization (20.89 km2, 4.22 %). Finally, the article proposes a 277.60 km multifunctional small urban green space network. By examining small urban green spaces, this study crafts a pivotal framework for enhancing green space equity in urban built-up environments, providing valuable insights for policymakers and urban planners. The approach has significant implications for developing multifunctional green networks in varied urban contexts and offers a model for wider application, serving as a reference for achieving green space equity in developing countries globally.

Ecosystem services provided by green spaces are closely related to human health, strongly supporting sustainable urban and territorial development. Urbanization has not only resulted in the reduction of green spaces but has also created inequalities in exposure. Inequitable green exposure creates disparities in residents\' access to the ecosystem services provided by green spaces and can lead to significant health inequities. In this context, we first categorized green exposures into active and passive types based on their characteristics. Second, utilizing the benefit transfer method and Gini coefficient, we estimated the value and equity of ecosystem services offered by these green exposures around residences at the municipality level in Japan from 2000 to 2020, with a focus on human health implications. Finally, we explored the potential relationship between socioeconomics and ecosystem service inequity. Our findings reveal that: 1) ecosystem service value per capita and equity provided by green exposure are significantly different across municipalities; 2) although most municipalities show an upward trend in per capita ecosystem service value around residences, ecosystem service inequity increases significantly; and 3) ecosystem service inequity is related to the socioeconomic factors of municipalities and could be non-linear. The results of this study suggest that the government should adopt indicators related to the ecosystem services provided by green exposure during urban planning. While focusing on per-capita ecosystem services, they should also consider the equitable distribution of ecosystem services to promote sustainable urban health development.

Pneumoconiosis is the most dangerous occupational disease in China. According to unofficial records, nearly million migrant workers were affected by pneumoconiosis in 2011, with the number increasing annually. Among them, a large number of migrant workers suffering from pneumoconiosis were not medically diagnosed. Therefore, fundamental questions remain unanswered: what is the background of workers who receive a diagnosis of pneumoconiosis, and how does pneumoconiosis affect their future and well-being?
In this study, we identified and surveyed 1,134 workers with pneumoconiosis in seven selected regions in China with substantially high incidences of pneumoconiosis by using a combination of cluster sampling, convenience sampling, and snowball sampling. We used demographic, medical, and rehabilitation conditions and welfare questionnaires to collect the data.
The findings highlighted the socioeconomic status of patients with pneumoconiosis. The majority of workers with pneumoconiosis were adult men who had received no higher education, who lived in rural households, and who were employed in mining or manufacturing industries. Among these workers, 52.8% had been exposed to dust at work for more than 10 years, and 53.1% received a diagnosis of stage II or III pneumoconiosis. More than half of the workers (569 workers, 50.2%) did not receive comprehensive, routine treatment; 33.4% (379 workers) visited a doctor when they experienced physical discomfort, and 6.6% (75 workers) never received treatment. Only 156 workers (13.8%) received rehabilitation services, whereas 978 workers (86.2%) never did. The study results also revealed the severe financial difficulties faced by patients with pneumoconiosis. Only 208 workers (18.3%) had access to work-related injury insurance, with the cost of pneumoconiosis treatment being a substantial burden for 668 workers (60.6%).
In this study, we explored the existing health and welfare problems faced by workers with pneumoconiosis in China and identified the social injustice and health disparities that these workers experience. We also clarified the primary challenges in implementing safety, health, and welfare policies for these workers and those who are exposed to high-risk environments, such as those working in mining.

Urban green space equity focuses on whether different social groups can equally share the well-being from green space, which is an important issue in the realm of environmental justice. We systematically introduced the origin and development of green space equity, explored its multidimensional progress in conceptual connotation, measurement methodology, phenomenon, mechanism, and regulation, and proposed the enlightenment for deepening the related studies. The green space equity originated from environmental social movement and environmental justice studies, and experienced multilevel evolution in topic constriction and theoretical interpretation. Although the connotation of green space equity was interpreted from various perspectives, its core idea was distributional equality. There was a frequently-used framework for measurement methodology of green space equity, whose spatial scale issue was critical. Due to the differences of characteristics, developmental stages, and institutional backgrounds between Chinese and Western cities, the phenomena and driving mechanisms of green space equity were different. The regulation strategies of green space equity could be summarized into three types, including green distributional equitable strategy, social recognitional justice strategy, and procedural justice orientated strategy. Future studies should deepen the research from the hierarchical logics for practice management, the fine-scale measurement methodology, the interpretation of mechanism for green space inequity in Chinese context, and simulation of differentiated regulation strategies. Social development endows green space equity with more practical tasks and theoretical logics, which is urgent to clarify the research progress to support the future research.
城市绿色空间公平聚焦不同社会群体能否平等共享绿色福祉,是环境正义领域的重要议题。本文系统梳理了绿色空间公平的起源和发展,探讨其概念内涵、测度技术、现象、机制和调控等多维进展,并提出研究深化的启示。绿色空间公平研究源于环保社会运动和环境正义研究,经历了话题收敛与理论演绎的多层次演进。绿色空间公平内涵多元,但分配平等是核心;绿色空间公平测度形成了成熟的技术框架,其空间尺度问题是关键;由于中西方城市特质、发展阶段、制度背景等差异,绿色空间公平现象特征和影响机制有所差异;对绿色空间公平的调控可归纳为绿色分配公平、社会承认正义、程序正义导向3类对策。未来可以从绿色空间公平的多层次实践逻辑、精细化测度技术、中国化机制解释、差异化对策仿真等方面深化研究。社会发展赋予绿色空间公平更多的现实任务与理论逻辑,迫切要求厘清绿色空间公平研究进展,支撑研究深化。.

The stability and resilience of the Earth system and human well-being are inseparably linked1-3, yet their interdependencies are generally under-recognized; consequently, they are often treated independently4,5. Here, we use modelling and literature assessment to quantify safe and just Earth system boundaries (ESBs) for climate, the biosphere, water and nutrient cycles, and aerosols at global and subglobal scales. We propose ESBs for maintaining the resilience and stability of the Earth system (safe ESBs) and minimizing exposure to significant harm to humans from Earth system change (a necessary but not sufficient condition for justice)4. The stricter of the safe or just boundaries sets the integrated safe and just ESB. Our findings show that justice considerations constrain the integrated ESBs more than safety considerations for climate and atmospheric aerosol loading. Seven of eight globally quantified safe and just ESBs and at least two regional safe and just ESBs in over half of global land area are already exceeded. We propose that our assessment provides a quantitative foundation for safeguarding the global commons for all people now and into the future.