Chen Ying
School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK.
NPJ Clean Air. 2025;1(1):1. doi: 10.1038/s44407-024-00001-6. Epub 2025 Mar 12.
New Delhi, India, is suffering from one of the worst air quality in the world, estimated to be responsible for 10,000 premature deaths per year. Although the high pollution level of fine particulate matter (PM) in New Delhi has attracted global attention, the true level of PM pollution could still be underestimated due to the inherent sampling bias associated with particle hygroscopic growth. This study compiles a comprehensive in-situ observation dataset from a series of recent studies in New Delhi, to quantify hygroscopicity-induced bias for the first time, and found that the more severe pollution the larger underestimation, and report the underestimate can be up to 20% (or 50 µg/m) of PM concentration on average in humid winter morning rush hours. This study fills in the gap of the understanding of PM pollution in the most polluted megacity in the world, and provides a calibration approach for future studies to develop better understanding of air quality in New Delhi.
印度新德里正遭受着世界上最严重的空气质量问题之一，据估计每年有1万例过早死亡与此有关。尽管新德里细颗粒物（PM）的高污染水平已引起全球关注，但由于与颗粒物吸湿增长相关的固有采样偏差，PM污染的真实水平可能仍被低估。本研究汇总了近期在新德里开展的一系列研究中的全面现场观测数据集，首次对吸湿引起的偏差进行量化，发现污染越严重，低估程度越大，并报告在潮湿的冬季早晨高峰时段，低估平均可达PM浓度的20%（或50µg/m）。本研究填补了对世界上污染最严重的大城市PM污染认识的空白，并为未来更好地了解新德里空气质量的研究提供了一种校准方法。
