Unusual Air Pollutants Traced Back to Eaton Fire in Pasadena & Altadena - Resident Discloses Remarkable Data Locally
In the heart of Pasadena, California, one individual took matters into their own hands when they became concerned about the air quality in their neighbourhood, particularly the levels of nitrogen dioxide (NO2), attributed to the presence of diesel trucks.
To address this concern, they started using a Plume Labs' Flow 2 device on January 8, 2025. This portable personal air quality monitor measures particulate matter (PM1, PM2.5, PM10), volatile organic compounds (VOCs), and gases such as nitrogen dioxide (NO2) using built-in sensors. The device provides real-time air pollution data via a paired smartphone app.
During their walks outside, the AQI ranged from High with High risk to low and moderate. Interestingly, the highest pm10 rating was observed while crossing the road with the most traffic. The particulate matter PM1 decreased over time for the most part, but there was an increase in pm10 and pm 2.5 in the 20-28 day period. Previously, NO2 readings were around 1.7, but by February 28, the average reading had dropped to zero.
High levels of VOC were detected at the Altadena market, which could be from cleaning chemicals or VOC leaching out after the Eaton Fire. Surprisingly, VOCs were higher five weeks after the fire than during the fire itself.
After the Eaton Fire was extinguished on February 22, all the particulate matter readings went down. However, the AQMD showed a good AQI score of 0-50, but warned that windblown ash particles may not be detected and hazardous ash may still be present in the air.
The individual's air purifiers at home have carbon filters, except for one, and carbon filters are effective at removing nitrogen dioxide from the air. Air purifiers with carbon filters can also remove some VOC from the air.
It's worth noting that Plume Labs, the company that produced the individual's air quality device, was bought by Accuweather in 2023. As of mid-2025, there are no relevant search results providing information about the current status of Plume Labs' Flow 2 device or its comparison to AQMD's Air Quality Index in terms of readings and measurements.
For comparison, data from November 2022 was downloaded and separated from the 2025 data. The individual believes that the reduction in particulate matter could be due to the air purifiers in their home, as they have at least one HEPA filter in each room and two filters in the office and living dining area.
In conclusion, the use of personal air quality monitors like the Plume Labs' Flow 2 can provide valuable insights into local air quality, complementing area-wide air quality reports. However, it's essential to understand the limitations of such devices, such as potential differences in sensor precision, calibration, and indoor/outdoor variability compared to fixed monitoring stations like those used by AQMD.
- To address the health-and-wellness concerns related to air quality, the individual began using the Plume Labs' Flow 2 device for environmental-science purposes on January 8, 2025, monitoring particulate matter, volatile organic compounds, and gases like nitrogen dioxide.
- The decrease in NO2 readings over time, paired with the use of air purifiers at home with carbon filters capable of removing nitrogen dioxide, suggests that the individual's proactive approach to monitoring air quality using a personal air quality monitor like the Plume Labs' Flow 2 may have contributed to the health-and-wellness improvements observed in their neighborhood, while also providing essential data on local climate-change effects such as air pollution.
