Data Sheet 1_Decoding population PM2.5 exposure in China: interplay of emissions, meteorology, and inequality (2013–2020).docx

Over the past decade, China has significantly improved air quality by integrating environmental policies with economic growth. Yet, environmental inequality remains a major challenge to social equity and sustainable development. This study examines the socioeconomic impacts of PM2.5 exposure using population data from 1,317 county towns across 32 provinces (2013–2020), employing meteorological normalization and population-weighted exposure indices. The findings reveal that lower-income regions (L4) achieved the highest PM2.5 reduction (54%), whereas wealthier regions (L1–L3), despite higher pollution levels, saw lower reductions (45–50%), highlighting an unequal emission reduction burden. PM_dw exhibits more stable spatiotemporal patterns than PM2.5, offering clearer insights into emission trends. Despite overall improvements, residents in less-developed areas still face higher exposure, while urban centers, benefiting from more resources, experience increased health risks. Vulnerable populations—including coal miners, the educated, women, and the older adult—disproportionately suffer from high exposure levels. Meteorological conditions have generally mitigated PM2.5 exposure, with the most significant dispersion effect in 2018. Notably, meteorology’s role in mitigating inequality in occupational exposure significantly decreased from 43.7% in 2013 to 4.5% in 2019, while its exacerbating effect on urban–rural inequality, contributing 43.7% in 2010, drastically reduced by 2020, even shifting to a slight alleviating role. To achieve equitable environmental governance and robust pollution control, policies must not only address regional economic disparities and prioritize protection for disadvantaged communities but also account for the complex and evolving modulating role of meteorological conditions on exposure inequality.

过去十年间，中国通过统筹环境政策与经济增长，空气质量实现了显著改善。但环境不公仍是制约社会公平与可持续发展的重大瓶颈。本研究基于中国32个省份共计1317个县城2013至2020年的人口数据，采用气象归一化（meteorological normalization）与人口加权暴露指数（population-weighted exposure indices）方法，探究了细颗粒物（PM2.5）暴露的社会经济效应。研究结果表明，低收入区域（L4）的PM2.5降幅最高，达54%；而富裕区域（L1至L3）尽管初始污染水平更高，其PM2.5降幅仅为45%至50%，这凸显了减排负担分配的不均衡性。相较于PM2.5，PM_dw展现出更为稳定的时空分布特征，能够更清晰地反映排放趋势变化。尽管整体空气质量有所改善，欠发达地区居民仍面临更高的污染物暴露水平，而依托更多公共资源的城市中心区域则面临着不断上升的健康风险。弱势群体——包括煤矿工人、受教育群体、女性以及老年人群体——不成比例地承受着高暴露水平带来的健康危害。气象条件总体上缓解了PM2.5暴露情况，其中2018年的大气扩散效应最为显著。值得注意的是，气象条件在缓解职业暴露不公方面的作用从2013年的43.7%大幅降至2019年的4.5%；而其对城乡不公的加剧效应在2010年的贡献占比达43.7%，到2020年已大幅减弱，甚至转变为轻微的缓解作用。为实现公平的环境治理与高效的污染防控目标，政策制定不仅需应对区域经济差距、优先保护弱势社区，还需充分考虑气象条件对暴露不公的复杂且动态的调节作用。