Source: Zhu, S., Liu, Z., & He, C. (2026). China’s high-speed rail widens urban–rural disparities in air pollution and public health. Nature Cities, 1-12.
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Promoting urban-rural integration and narrowing the urban-rural gap are important strategic goals for the Party and the country to achieve common prosperity and advance Chinese-style modernization. Against the backdrop of comprehensively building a unified large market and promoting coordinated regional development, major transportation infrastructure such as high-speed rail is expected to break down spatial barriers and promote urban-rural connectivity. However, a key question remains to be clarified: can the policy dividends brought by these infrastructure projects be evenly distributed between urban and rural areas? Professor He Canfei and Researcher Zhu Shengjun from Peking University's School of Urban and Environmental Sciences, together with Assistant Professor Liu Ziliang from Fudan University, explored this strategic concern, with the latest findings published in Nature Cities. The study found that although the opening of high-speed rail benefits both urban and rural areas (manifested in reduced environmental pollution and cardiovascular deaths), urban areas benefit significantly more, objectively widening the urban-rural development gap and providing important empirical evidence for reflecting on how policy dividends can benefit urban and rural areas more fairly.
This study constructed multi-source big data covering micro-level corporate emissions, high-resolution (1 km) satellite remote sensing, and fine-grained (5 km) public health data, and found that air pollution in both urban and rural areas is trending downward, but the rate of decline is faster in urban areas. Further analysis shows that in densely populated eastern and central China, rural PM2.5 emission levels differ from urban levels. Due to the lack of advanced production technology, strict environmental supervision, and necessary remediation resources, some rural areas (such as central regions) have higher exhaust emission intensity (i.e., emissions per unit of output) than urban areas. This means that while rural areas face environmental risks, their ability to resist risks and self-repair lags behind that of urban areas.Figure 1 Trends in urban and rural air pollution in China (2013-2016).
These spatial differences may be further influenced by certain specific policy tools (such as high-speed rail construction aimed at promoting regional connectivity). To address this, the research team used a triple difference model (DDD) to comparatively analyze changes in environmental and health variables in urban and rural areas before and after the high-speed rail opened, revealing the spatial asymmetry of the impact of high-speed rail. The study found that after the high-speed rail opened, both urban and rural areas showed an overall downward trend in air pollution and cardiovascular disease deaths, demonstrating the widespread ecological well-being brought by major infrastructure investments. However, in terms of magnitude of improvement, urban areas decline faster than rural areas, and this stepwise difference in benefit has led to a relative widening of the environmental and health gap between urban and rural areas. If we ignore this spatial difference in the magnitude of benefits, it will be difficult to fully assess the true social welfare effects of large-scale infrastructure construction.Table 1 Regression results of high-speed rail opening on urban and rural air pollution and public health impacts
This widening benefit gap is related to the spatial reallocation of production factors. As an efficient connectivity tool, high-speed rail not only optimizes regional resource allocation but also further strengthens the city's advantages as centers of innovation and capital. After the high-speed rail opens, urban enterprises will find it easier to obtain external investment and support for the flow of high-end talent, thereby accelerating the transition to green and high-tech industries and enjoying more environmental support policies. In contrast, rural areas benefit less, causing rural areas to slow down their pace in the emission reduction process driven by technological upgrades.
Figure 2: Analysis of the mechanism of resource flow to cities after the opening of high-speed railThe study further examined the evolution of this influence across spatial and temporal dimensions. The results show that the urban-rural benefit gap caused by the opening of high-speed rail will not automatically close over time. In the more than seven years since the high-speed rail opened, this asymmetric benefit between urban and rural environment and health has been continuous and even expanding. In terms of spatial distance, this inequality effect is most pronounced within 3 to 6 kilometers around high-speed rail stations and gradually diminishes as the distance to traffic nodes increases. These results indicate that although the spatiotemporal convergence brought by transportation facilitation can improve efficiency, its effects are spatiotemporal heterogeneity, and future regional development and green transition policies need to consider such spatiotemporal heterogeneity.Figures 3 and 4: Curves of urban-rural gaps over time and distanceChina has achieved remarkable accomplishments in high-speed rail construction and regional connectivity. However, this study offers a brand-new perspective: some policy tools that seem unrelated to environmental governance—such as cross-regional, large-scale high-speed rail network construction—will actually reshape the environmental and health landscape between urban and rural areas. Although such policy tools can benefit both urban and rural areas, due to the spatial tendency of factor flows, rural areas may gain even less. The study suggests exploring the establishment of urban-rural environmental compensation mechanisms in the future, encouraging beneficiary cities to transfer green technologies to surrounding rural areas, and strengthening joint urban-rural monitoring and coordinated governance. This is not only about improving air quality, but also about how to ensure that, under the framework of building a "unified market," every citizen, whether in cities or rural areas, can more fairly share the fruits of green development.
This study provides a new perspective for understanding the interaction between transportation infrastructure and environmental justice, emphasizing the need to fully consider coordinated urban-rural development in rural areas when formulating regional policies. The research findings were published in Nature Cities under the title "China's high-speed rail widens urban–rural disparities in air pollution and public health" (click to read the original article at the end of the article). Researcher Zhu Shengjun from the School of Urban and Environmental Sciences, Peking University, and Assistant Professor Liu Ziliang from the Advanced Institute of Social Sciences at Fudan University (PhD graduate from the School of Urban and Environmental Sciences, Peking University) are co-first authors; Assistant Professor Liu Ziliang from the Institute for Advanced Studies in Social Sciences, Fudan University, and Professor He Canfei from the School of Urban and Environmental Sciences, Peking University, are co-corresponding authors.
