Indoor Air Quality Alert: Pacific Tsunami Coastal Flooding

What is the location of the flooding?

On July 29, 2025, an 8.8 magnitude earthquake that struck off the coast of Russia’s Kamchatka Peninsula triggered tsunami warnings across the Pacific Ocean, affecting island residents and people living on the coasts of four continents (1). The tsunami warning was issued for coastal regions all along the Pacific Ocean, including parts of Russia, Japan, Australia, New Zealand, China, South and Central America, Hawaii, and the U.S. West Coast (2).

As the tsunami remains in effect for some regions, potential coastal flooding is a concern in many communities in the region. However, as time passes the threat is diminishing across the Pacific Rim.

Which cities or areas are affected by the tsunami?

The extent of flooding from the tsunami is still being assessed, though in some areas like Hawaii and Japan widespread flooding didn’t materialize (3). Areas affected by recent flood and tsunami warnings include (4):

• Alaska, California, Hawaii, Oregon, and Washington
• Australia
• British Columbia, Canada
• Chile
• Ecuador
• Federated States of Micronesia
• French Micronesia
• Fiji
• Guam
• Kamchatka Peninsula, Russia
• Japan, including Iwate Prefecture and Hokkaido
• Mexico
• New Zealand
• Peru
• The Philippines
• Samoa
• Solomon Islands
• Tonga

Severo-Kurilsk, a town in the Kuril Islands, Russia, was severely impacted by flooding.

What is the current containment status of the flooding?

As of July 30, tsunami waves have been continuously observed and monitored, with varying degrees of impact. Efforts are focused on ensuring public safety through warnings and advisories.

Tsunami waves have been recorded in multiple locations, with some areas experiencing waves several feet high. Authorities are continuing to monitor the situation and provide updates as necessary (5).

Are there any evacuation orders or alerts in place?

Evacuation orders and alerts were issued in several regions as a precautionary measure due to the tsunami threat.

In Russia, local authorities declared a state of emergency in affected areas. In Japan, over 2 million people across multiple municipalities were urged to evacuate. Hawaii issued evacuation warnings, and residents were advised to move to higher ground. Along the U.S. West Coast, officials urged people to stay away from beaches and coastal areas due to dangerous currents and potential flooding.

However, evacuation warnings were lifted in Hawaii, along the U.S. West Coast, in Fiji, Tonga, the Philippines, Guam, and other jurisdictions.

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.