T he recent wildfires in Altadena and Pacific Palisades have been contained, but their impact on air quality persists.

In January, the South Coast Air Quality Management District reported unhealthy air quality levels in Los Angeles County due to smoke from the Palisades, Eaton and Hurst wildfires. Even after the fires have been extinguished, residual smoke and ash can continue to affect indoor air quality, posing health risks to residents.

Air pollution is recognized as the second highest risk factor for noncommunicable diseases, contributing to conditions such as heart disease, lung cancer and chronic respiratory issues.

Taking proactive steps to improve air quality is essential for long-term health and well-being.

How air filters can help after wildfires

Filters are essential tools for improving indoor air quality by capturing fine particles and other pollutants that linger after wildfires. High-efficiency particulate air, or HEPA, filters and minimum efficiency reporting value filters are commonly used to combat poor air quality.

HEPA filters capture at least 99.97% of particles as small as 0.3 microns, making these devices highly effective in removing wildfire smoke, allergens and other airborne pollutants. MERV filters are rated on a scale from 1 to 16, with MERV 13 and higher being recommended for wildfire smoke. While MERV filters trap fine particles, they may not capture the smallest pollutants as efficiently as HEPA filters, making HEPA the superior choice for wildfire-related air pollution when available.

A good air purifier should have an activated carbon/charcoal filter to absorb harmful gases and odors, a HEPA or MERV filter to capture fine particles, a clean air delivery rate geared to the size of your space, and California Air Resources Board certification, which can be checked at arb.ca.gov.

Community-led air purification efforts

In response to deteriorating air quality, community initiatives have emerged to provide relief. For instance, Clean Air Claremont, a group formed in response to the Eaton fire, has been constructing do-it-yourself air purifiers using MERV 13 filters and box fans. These devices are distributed to residents affected by smoke and ash. The group has optimized its building process, producing 40 purifiers in one hour during recent sessions.

How to obtain an air filter

Residents have several options to improve indoor air quality. HEPA purifiers are available for purchase at home improvement stores and online

retailers. The South Coast Air Quality Management District is providing free air filters to residents of Boyle Heights, East Los Angeles and Commerce. Residents must apply online — first come, first served — and submit a document verifying residence in a target areas. For the application and more info, visit aqmd.com.

South L.A. Cafe has also launched an initiative for wildfire victims to receive a free air purifier from the brand Levoit Lifestyle. Applicants must receive approval before picking up or arranging delivery of the purifiers. For more information, visit its Instagram.

For those seeking a DIY alternative, the Corsi-Rosenthal Box is a cost-effective option, requiring only a box fan, five MERV 13 air filters and duct tape. Instructions are available from the Environmental Protection Agency at epa.gov.

Key considerations for air filters

When using air purifiers, it’s important to place them in rooms where you spend the most time, such as bedrooms and other living spaces. In areas affected by wildfires, filters should be replaced more frequently than the standard 90-day interval to maintain effectiveness. For those building DIY air purifiers, using newer model box fans can help reduce fire risks.

By taking these steps, you can improve indoor air quality and health risks associated with wildfire smoke. While wildfires may be seasonal, air pollution remains a year-round concern, making air filtration an investment for long-term health. For more information, visit the Los Angeles County Department of Public Health’s news releases at publichealth.lacounty.gov.