Indoor Air Quality Alert: Central United States Flooding

What is the location of the flooding?

On April 4, 2025, a "catastrophic and potentially historic flash flood event" was affecting a 1,000-mile stretch of the United States, spanning from Texas to Ohio (1).

Flooding continued through April 8, mostly impacting Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Mississippi, Missouri, Michigan, Ohio, Oklahoma, Tennessee, and Texas (2). Flood warnings were in effect for these 15 states,  

The flooding is being driven by a stagnant atmospheric river and is overwhelming small streams, drainage systems, and potentially major rivers such as the Ohio and Mississippi River tributaries.

Which cities or areas are affected by the flooding?

Significantly affected cities and towns include:

• Dyersburg, Tennessee
• Evansville, Indiana
• Frankfort, Kentucky
• Harrodsburg, Kentucky
• Jackson, Tennessee
• Jonesboro, Arkansas
• Lexington, Kentucky
• Little Rock, Arkansas
• Memphis, Tennessee
• Paducah, Kentucky
• Poplar Bluff, Missouri
• Selmer, Tennessee

Many areas were experiencing rainfall totals ranging from 6 to over 16 inches on April 4, and flooding continued through the weekend and into the following week.

What is the current containment status of the flooding?

Though the raining has stopped, the flooding is ongoing and not yet mitigated (3)(4). Emergency responders are actively assessing damage, but no complete containment has been reported. Infrastructure damage and high water levels are hampering response efforts in several locations.

Are there any evacuation orders or alerts in place?

Numerous flood watches and flash flood warnings are in effect across a broad area from Texas to Florida and to northern Ohio, including much of Kentucky.

Some communities have declared states of emergency, such as in Kentucky and Missouri, and emergency alert systems, including tornado sirens in Little Rock, have been activated. Residents are being advised to remain alert, have emergency supplies ready, and prepare for possible evacuation in areas at highest risk.

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.