When wildfires ignite, the damage doesn’t stop at the flames. 

Wildfires release smoke, ash and invisible particles that travel miles, turning clear skies into a health hazard. During these events, the Air Quality Index (AQI) often becomes a trusted source for gauging the safety of the air – but just how accurate is the AQI when ash and toxic chemicals are in the mix? 

Understanding the AQI, its limitations, and what you need to know to stay safe becomes suddenly crucial when the air around you becomes a threat. Here, we explore the facts, warnings and precautions that matter most during wildfire season.

Understanding the Air Quality Index (AQI)

The Air Quality Index, or AQI, is a numerical scale used to communicate the quality of the air and its potential health impacts. Ranging from 0 to 500, it’s divided into categories that describe the level of health concern, from “Good” (0–50) to “Hazardous” (301–500).

The AQI focuses on five major pollutants:

  • Ground-level ozone
  • Particulate matter (PM2.5 and PM10)
  • Carbon monoxide
  • Sulfur dioxide
  • Nitrogen dioxide

Each pollutant gets a sub-score, and the highest of these determines the overall AQI; all sounds well and good, except there’s a catch: the AQI isn’t perfect.

The Hidden Threat of Ash Particles

While the AQI provides essential insights, it has notable blind spots. For example, the South Coast Air Quality Management District and the county public health department recently issued a windblown dust and ash advisory. Why? Because ash particles are too large for AQI monitoring systems to detect. This means that while your weather app might show an AQI of 150 (Unhealthy), the air could still contain harmful ash particles from wildfire debris that are unaccounted for.

Smoke’s Toxic Cocktail: Expert Insights

Wildfire smoke isn’t just unpleasant – it’s downright dangerous. Anthony Wexler, Director of the Air Quality Research Center at UC Davis, explains that smoke from fires contains a mix of harmful substances, such as lead, asbestos, and arsenic. But that’s not all – in urban areas, the situation worsens as burned homes, cars, and household items release additional toxic chemicals into the air.

Anne Kelsey Lamb, Director of Regional Asthma Management and Prevention, highlights another alarming fact: during the 2018 Camp Fire, smoke containing lead was detected 150 miles away from the fire zone. The far-reaching impact of wildfire smoke and its capacity to infiltrate areas far beyond the flames is a characteristic that must be taken seriously to maximize safety.

How to Protect Yourself During Wildfire Events

When wildfires strike, safeguarding your health should be your top priority. Here’s what you can do:

1. Monitor Air Quality and Advisories

Stay informed through trusted sources such as:

Checking these updates regularly can help you decide when it’s safest to step outside – or stay indoors.

2. Wear Protective Masks

Even if ash isn’t visible, tiny, harmful particles may still linger in the air. Wearing a properly fitted N95 mask can shield you from inhaling these pollutants; remember, not all masks are created equal – your cloth mask from the pandemic won’t cut it here.

3. Limit Outdoor Activities

This is the time to channel your inner couch potato. Avoid outdoor exercise or strenuous activities, as they increase the amount of air (and pollutants) you inhale.

4. Keep Indoor Air Clean

Close windows and doors, and use air purifiers with HEPA filters. If you don’t have an air purifier, even a damp towel under the door can help block some smoke from entering.

The Limitations of the AQI and What It Means for You

While the AQI remains a valuable tool, it’s crucial to recognize its gaps. For example:

  • Ash particles: The AQI doesn’t account for them, yet they pose significant health risks
  • Toxic chemicals: The specific dangers of smoke from urban fires, like those in LA, are not fully understood or included in AQI measurements

This doesn’t mean you should ignore AQI data – it’s still an excellent general indicator. However, it’s wise to use it alongside local health advisories and your own observations; if you see ash on your car or smell smoke, take precautions – even if the AQI isn’t screaming ‘Hazardous.’

Long-Term Health Risks

Exposure to wildfire smoke isn’t just a short-term nuisance. Prolonged or repeated exposure can lead to chronic respiratory conditions, cardiovascular issues, and even premature death; vulnerable groups like children, the elderly, and individuals with pre-existing health conditions are especially at risk.

Best Practices for Staying Safe

The best defense is preparation. Here’s a quick recap of steps to keep you and your family safe:

  • Stay updated: Regularly check trusted sources for air quality alerts
  • Create a safe indoor space: Invest in an air purifier and seal your home from outdoor air
  • Use protective gear: N95 masks can make a significant difference
  • Plan ahead: Have a go-bag ready with essentials in case you need to evacuate

And don’t forget to check in on neighbors who may need assistance, such as the elderly or those with mobility challenges.

A Call to Action: Let’s Clear the Air

Wildfires and their impact on air quality are challenges we’ll continue to face, especially with climate change intensifying their frequency and severity. Staying informed and prepared is key to weathering the smoke – literally.

So, next time you’re scrolling through your weather app and see an AQI reading, remember: there’s likely more to the story. Trust your senses, heed advisories, and take every precaution; when it comes to the air you breathe, there’s no such thing as being too cautious.