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Hello Folks,
These are indeed challenging days. I wanted to update you on my previous email regarding Air Quality readings. The article I sent you all is updated regularly.

understanding-purpleair-vs-airnow-gov-measurements-of-wood-smoke-pollution-562923a55226

Some changes that I thought I’d pass on to you are summarized below. I keep purpleair.com open on my computer dashboard and check it frequently to determine when/where to get

outside. I now toggle back and forth using the updated recommendations below ie LRAPA and AQandU to my nearest sensors.

Edit: 9/1/2020: PurpleAir will soon feature a 3rd correction factor specifically created by the EPA. In the meantime, EPA recommends that you use AQandU instead of LRAPA, especially if the AQI is higher than 150. From the EPA: “The US EPA correction will be available on PurpleAir.com as a selection shortly. Until then, the AQ&U correction more closely matches our correction throughout a wide range of concentrations while LRAPA shows significant underestimation above 65 ug/m3 [150 AQI].” (bracketed AQI added by me) If you’re curious about the EPA formula, see note #5 at the end of this article. Note that an earlier version of this article you’re reading suggested using LRAPA. This was before the EPA gave me this updated recommendation. For more on LRAPA vs. AQandU, see note 6 at the end of this article.

fire.airnow.gov

(Added 8/25/2020): Recently, the folks at AirNow.gov created a map specifically useful for wildfire smoke at https://fire.airnow.gov. This page is great because it includes both lower cost (e.g. PurpleAir) sensors and the official permanent sensors, and also applies correction factors automatically to keep them all on the EPA approved scale. Permanent sensors are the large circles, and the lower cost sensors are the smaller squares.

https://fire.airnow.gov/?lat=37.79798000000005&lng=-122.17770999999999&zoom=12

The downside of fire.airnow.gov is that you still have a time lag when conditions change rapidly. The screenshot above was taken at 2:52 PM, while PurpleAir was already reflecting rapidly improving conditions.

If you want the most up-to-date AQI measurements, I’d recommend using Purple Air with AQandU enabled. Once the EPA conversion factor is available on PurpleAir I’d use that instead. Given the potentially greater danger of wood smoke particles, it’s probably worth treating the AQI numbers with somewhat greater caution than on days that don’t involve wood smoke. If you decide to use the front page AirNow.gov, be aware that the delay may be delayed and not specific to your current location. fire.airnow.gov gives you a nice map, but will also be delayed if conditions are changing rapidly.

Stay Safe folks! Also, I wanted to let you know that I have updated my Serene Outdoor Treatment Deck to feature a beautiful canopy tent with HEPA filters cleaning the air and outdoor heaters that make you warm and cozy! Crazy to add heat after several scorching days! We are indeed being challenged to meet each new day and make it work for us!

Sincerely,

Denise

https://thebolditalic.com/understanding-purpleair-vs-airnow-gov-measurements-of-wood-smoke-pollution-562923a55226

outside. I now toggle back and forth using the updated recommendations below ie LRAPA and AQandU to my nearest sensors.

fire.airnow.gov

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