At about 2 a.m. on Thursday (July 25, 2024), a pungent odor of unknown origin began to appear in Chengguan District, Qilihe District and other areas of Lanzhou City, Gansu Province, China. Lanzhou City's emergency, public security, and ecological environment departments have launched an investigation and traced the source.

According to CCTV News, in the early hours of Thursday morning, many citizens in Lanzhou City, Gansu Province posted videos on the Internet saying that they were awakened by an inexplicable irritating smell. Some netizens said that "I have a headache and my heartbeat is accelerating", and some netizens wore N95 masks because of this.

According to statistics, netizens in Chengguan District, Qilihe District, Anning District and other places in Lanzhou City have reported the problem of irritating odors. A citizen in Lanzhou said that he lives near Hejiazhuang Railway Station in Chengguan District. The smell is particularly pungent and he was awakened twice. Another citizen said that at around 2 a.m., he was awakened by the odor at home and described the smell as a bit like hydrogen sulfide. He thought it was burning garbage or a fire somewhere.

After receiving the relevant alarm, Lanzhou City Emergency, Public Security, Ecological Environment and other departments have launched investigations and tracing. At present, the investigation and tracing work is still in progress.