Indoor Air Quality Alert: Northern China Flooding

What is the location of the flooding?

Since July 23, 2025, relentless rainfall has caused severe flooding and landslides across northern China, particularly in Beijing and Hebei province (1). Beijing’s Miyun district, near the Miyun Reservoir, has been heavily impacted, with floodwaters submerging homes and infrastructure.

In Hebei, Baoding city, especially Fuping county, and Chengde city have faced record-breaking rainfall, exacerbating flood risks (2). Beijing’s topography, with mountains trapping moist air, amplifies rainfall intensity.

Which cities or areas are affected by the flooding?

The flooding has directly impacted the following areas:

Over 30 roads and power lines in more than 130 villages, particularly in Miyun, have been damaged, with floodwaters devastating homes and a nursing home in Taishitun, where 31 elderly residents died.

What is the current containment status of the flooding?

As of August 4, 2025, floodwaters are receding in some areas, but Beijing remains on red alert with forecasts of up to 200mm of rain in hilly districts like Mentougou and Huairou. Hebei’s uncontained rivers and ongoing rain pose risks of further flooding.

Over 4,000 rescuers, supported by helicopters and boats, are clearing debris and delivering aid, with efforts focused on restoring infrastructure (3).

Are there any evacuation orders or alerts in place?

Over 90,000 people have been evacuated across Beijing, including 17,000 from Miyun and 10,400 from Huairou, with thousands more relocated from Hebei’s Fuping, Xinglong, and Luanping counties.

Beijing’s red alert, issued August 3, 2025, warns of flash floods and landslides, urging residents to stay indoors. Hebei issued a red alert for mountain torrents in Fuping and Shijiazhuang counties, with shelters like Liudaohe Middle School in Xinglong housing over 800 evacuees (4).

Authorities have allocated 350 million yuan ($48 million) for relief across nine regions.

How can I protect myself from mold after flooding?

It’s important to take steps to prevent mold after a flood.

Before entering a flooded area, make sure it is safe and free from electrical hazards or structural damage.
Use protective gear: wear gloves, goggles, and a KN95/FFP2 mask to minimize exposure to mold spores.
If there is still standing water, remove it as quickly as possible. Use pumps, wet-dry vacuums, or buckets to extract the water.
Open windows and doors to facilitate air circulation and use fans, dehumidifiers, and HVAC systems to help dry the space. This step is crucial within the first 24-48 hours after flooding to prevent mold growth.
Remove and discard any items that have been severely damaged by floodwater and cannot be thoroughly cleaned and dried. This includes carpets, upholstered furniture, mattresses, and any other porous materials.
Thoroughly clean all hard surfaces with a detergent or cleaner suitable for mold remediation. Use a solution of 1.5 cups of bleach mixed with one gallon of water to disinfect nonporous surfaces. Never mix bleach with ammonia or other cleaning products, as the fumes are toxic.
Maintain an indoor relative humidity (RH) of 35-50%. High humidity promotes mold growth, so consider using dehumidifiers in damp areas.
Run a high-performance air purifier for mold, both during and after the mold removal work.
If the flooding and mold damage are extensive, consider contacting professionals specializing in mold remediation to ensure proper cleanup and restoration.

Remember, mold can pose health risks, so it's important to take these steps promptly and thoroughly. If you experience persistent mold-related health issues or have concerns about extensive mold growth, consult with a medical professional or a mold remediation specialist.