Breathing hazard: recent sandstorm poses distinct respiratory mortality burden in China

To the Editor: Sand and dust storms (SDSs) are lower-atmosphere events that occur when strong winds pass over dry loose sand or soil.1 The frequency and duration of SDSs had substantially declined across China in the past 2 decades due to ecological restoration programs.2 However, a concerning resurgence of SDS activity has been observed in recent years. An unprecedented severe SDS event in April 2025 swept across China, extending from northern regions to southern cities such as Guangzhou and even reaching Hainan Island, covering more than 4.3 million square kilometers.3 This southward expansion of SDSs impacts raises urgent public health concerns due to the dense populations in the affected areas. We aimed to estimate the excess deaths from respiratory diseases attributable to SDS that occurred from January 1 to April 26, 2025, at the city level across China and in different geographical regions. Mortality data from respiratory diseases were obtained from the National Mortality Surveillance System of China.4 Daily ambient air pollution data were collected from the National Urban Air Quality Real-time Publishing Platform (https://quotsoft.net/air/). We identified SDS events at the city level using PM10 concentrations and PM2.5/PM10 ratio. Specifically, an SDS event was defined for each city as any day satisfying the following criteria: (1) the daily average PM10 concentration was >50 μg/m3;5 (2) a daily PM2.5/PM10 ratio was