Surprising Air Pollutants from Eaton Fire in Pasadena & Altadena – Local Resident Shares Astounding Data

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Here are my findings on how much air pollution I have been exposed to since the Eaton Fire started on January 7, 2025. I live about 1.7 miles from the edge of where homes were destroyed. I typically travel  as far west as Burbank and as far east a Glendora but only for a few hours each time. The shocking results show both good and bad measurements.

Background Data & Methodology

On January 8, I started carrying with me on my purse a Plume Labs’ Flow 2. I first used the Plume Labs’ Flow in 2022 when I wrote a review of the device for Auto Futures. I did not use it since November 2022.

The Plume Labs’ Flow connects to an app and records the location, time, date and rates the pollution stats in AQI(Air Quality Indexes) for

  • Particulate matter:  PM1, pm 2.5, pm10
  • Nitrogen Dioxide NO2
  • VOC Volatile Organic Compounds.

There were a total of 81671 record recorded from January 8 to February 28. For comparison data from November 2022 was downloaded. Plume Labs supplied the data in five different csv files which I imported into five sheets and separated the data recorded in 2022 as a comparison. All the data itself was too overwhelming, so I average each AQI in time sections and them made charts to show the averages for each file in days elapsed.

 

Particulate Matter Matters

I was happy to discover that for the most part the particulate matter of the minute PM1 reduced over time. In the 20-28 day period there was an increase in pm10 and pm 2.5 but after the fire was extinguished on February 22 all the particulate matter reading went down.

I also think that since much of my time is spent indoors in my home where I currently have a least one air purifier filter in each room and two filters in the office and in the living dinning area. HEPA filters do a good job of cleaning out particulate matter.

No Back Knocks for NOX, Knock on Wood

I was also very concerned about Nitrogen Dioxide, because that is released from diesel trucks and there were many trucks bringing goods to Altadena.

I hate nitrogen dioxide, you can’t see but if you breathe it’s very bad for your lungs. Previously when I used the sensor in 2022 the readings for NOX were at around 1.7 and by February 28 there average down to zero. A pleasant surprise.

I want to also note that everyone of the air purifiers in my home have carbon filters expect for one. The Vornado in the bedroom has two layers of carbon filters. Carbon filters will reomove Nitrogen Dioxide form the air.

The Very Volatile Volatile Organic Compounds

Here’s were I was surprised and somewhat shocked. Five weeks after the fire, VOCs were higher than during the fire. VOCs are released over time or can be released due to heat.

VOCs are not filtered by a typical N95 mask they require a special carbon filter to be removed from the air.

Air purifiers with carbon filters can remove some VOC from the air. So what happened? The last week of February I did make a trip to Altadena to support the market there. When looked at the map there were high levels of VOC at the market which could be from cleaning chemicals or from VOC leaching out after the fire over time.

Lessons Learned

I was wondering what happened to the Plume device. The company sent a notice that they were no longer selling Flow sensors. Plume Labs was bought by Accuweather in 2023.

When I looked today at different AQI, I found that Accuweather and Plume Labs were showing Poor Air Quality while AQMD was showing a better index. Plume now measures O3 ozone which my device does not.

While writing this article inside the levels low with a score of 17 while Plume Labs for my area Pasadena shows Poor Quality with a score of 51.

AQMD showed a score of good 0-50 with the disclaimer:”

“Windblown ash particles may be too large to be detected by air quality instrumentation and not reflected in the Air Quality Index (AQI) map. However, they are typically visible to the naked eye either in the air or on outdoor surfaces. Although the AQI may show green, hazardous ash may be present in the air. If you smell smoke or see ash, please take precautions”

I took a walk around the block and the AQI ranged as High with High risk to low and moderate. Walking across the old road with the most traffic showed a high pm 10 rating. By the time I returned home it was back to moderate while inside the house is now moderate in the kitchen where there are no air purifier.

I hope there are many more Plume Flow devices out there correctly monitoring the AQI–perhaps Plume Labs has deployed there devices in many more areas than AQMD which is why the readings are higher from Plume Labs.

We will not know how badly this air quality has affected residents until years in the future with lung cancer and asthma stats. But I can tell you one of my neighbors has had lung cancer treated twice and two kids on the block have asthma and that all happened before the Eaton Fire.