Los Angeles Skies Are Deceptively Clear

Early last week, the view out my windows had become alluringly clear. The peaks of the San Gabriel Mountains that had been obscured by a cloud of smoke from the Eaton Fire that devastated the city of Altadena reappeared. The campfire smell had blown away — from this part of Los Angeles, at least. The landscape seemed to say, it’s safe to come outside.

Looks can be deceiving. One of the first days I ventured outside again, just to walk the dog down and back up our steep hill, I felt my throat burn by the time we arrived back at the house. That sensation, plus having a baby barely more than a year old, led my family to stay locked in for a few more days.

It’s tricky to know when it’s okay to return to the outdoors during an ongoing wildfire crisis. The area map on Watch Duty looks good: The 800-acre Hurst Fire up near Santa Clarita has been entirely controlled, and no new major blazes took hold in the L.A. area despite windy conditions on Monday. As I write this, the devastating Eaton Fire has now been 89% contained, and the Palisades has reached 63%. As early as the weekend after the fires started, when I was helping a family member clear broken tree branches in the San Gabriel Valley, the fire and its smoke were no longer visible over the horizon. By now, some residents have been allowed to return to areas now deemed safe.

Still, it may be a while before the traumatizing wildfires burn out entirely. Until they do, and even after, an undeniable level of uncertainty comes with every breath we take.

In my neighborhood, the Air Quality Index has been remarkably low over the past week. When consulting my phone’s Weather app and resources such as IQAir, measurements have been moderate or even good — in fact, better than the numbers posted on many perfectly normal L.A. days with no wildfires burning, when haze and smog still cloud the sky. As many people have discovered during these horrible fires, however, AQI is far from a perfect indicator of whether the air outside is okay. It might suffice on an ordinary morning for telling you whether it’s a good or bad day to go for a run, but it is not, on its own, able to account for the toxic soup that burned around L.A.

One of the major concerns about these fires that engulfed whole neighborhoods in Pacific Palisades and Altadena is that our homes, more than ever before, are full of plastic and other chemicals that become extra dangerous when burned. While AQI measures everyday problems like small particulate matter and smog, it doesn’t include pollutants like copper, plastic compounds, asbestos, and other things that might have gotten into Los Angeles’ air.

To find out exactly what chemicals came out of the Eaton Fire, Caltech professor Mike Brown (aka @plutokiller, after his role in the demotion of the former ninth planet) took ash from his house to campus to measure its chemical composition. (Note: My day job is at Caltech.) The result: titanium from new house paint, lead from old house paint, and lots of other heavy metals. “Treat that ash like it’s toxic folks,” he wrote on BlueSky, “(because it is).”

In and around devastated communities such as Altadena, it’s obvious one must proceed with extreme caution regarding the ash and the air itself. In other parts of the city, it’s hard to be sure. Neighbors of ours have resumed their communal daily dog walk, but with some hesitation about whether it’s okay to go outside maskless for even 30 minutes. When a sore throat or a headache comes on, we wonder whether the air is to blame. Before the fires, my family used to take a nightly dog walk of at least an hour, which now includes carrying the baby. Since she is too young to wear a mask, I don’t know when we'll feel that free again.

A small comfort is that, indoors at least, we were ready. Three air purifiers run round-the-clock in various parts of my house because of our proximity to a freeway and the general mediocrity of the Los Angeles air.

But, honestly, it sucks to sit inside in a place so beautiful. Winter in L.A. is gorgeous, full of cool but sunny days perfect for afternoon walks and hikes in places that would be too sun-drenched and blazing hot to visit in the summer. This winter, even with some rain finally in the forecast, our hikes are burned and our air is uncertain.