Last defense in climate change: Assessing healthcare inequities in response to compound environmental risk in a megacity in Northern China

The compound risk of extreme heat and air pollution in the context of climate change has become an important challenge for megacities in Northern China. Severe spatial differences exist in healthcare facilities, which are the last defense to protect the health of residents. Understanding the match between compound risks and healthcare services is important for ensuring the basic well-being of residents. We selected 255 census units in Tianjin to comprehensively assess the healthcare services and risks of hazards, exposures, and social vulnerabilities in order to explore the match between risks and services. We quantified and graded environmental quality on a 5-point scale and investigated inequalities in risk-service relationships across different regions using correlation analysis, analysis of variance (ANOVA), and LISA. The results showed that: (1) the level of compound risk and the variability of risk increased with environmental degradation, main urban areas exhibited the highest level of risk, while suburban and district centralized construction areas demonstrated significant variability in risk; (2) the relationship was significantly imbalanced between healthcare services and risk in suburban and peripheral districts and counties, while the main urban areas and rural areas showed high and low levels of matching respectively; and (3) blue-green spaces could effectively alleviate the pressure on healthcare services in the main urban area and rural area. The results obtained in this study provide references for healthcare allocation strategies in areas with different degrees of environmental degradation, and we call for further planning of healthcare facilities in megacities to enhance their ability to adapt to climate change risks.