# Reasons for exceptionaly high indoor readings?
**URL:** https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783
**Category:** Sensors
**Created:** [March 1, 2023, 1:53pm UTC](https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783 "2023-03-01T13:53:37Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@mpurple](https://community.purpleair.com/u/mpurple)
#### Post date: [March 1, 2023, 1:53pm UTC](https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783/1 "2023-03-01T13:53:38Z")
I’m curious if anyone knows any reasons why my indoor air quality would be so bad compared to outdoor? I do not have a fireplace, wood stove, or gas stove, but this morning the current reading is 171 on my indoor sensor and 61 on my outdoor one. We have noticed spikes during cooking, but the last
thing that was cooked was oatmeal an hour and a half ago (on an electric stove.)
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### Author:  [@Ethan](https://community.purpleair.com/u/Ethan)
#### Post date: [March 1, 2023, 6:01pm UTC](https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783/2 "2023-03-01T18:01:58Z")
Hi @mpurple, do you use an [ultrasonic humidifier](https://www2.purpleair.com/blogs/blog-home/ultrasonic-humidifiers-a-source-of-pm2-5?_pos=1&_sid=108c65353&_ss=r)? We have seen humidifiers like this increase the AQI significantly in homes before.
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### Author:  [@mpurple](https://community.purpleair.com/u/mpurple)
#### Post date: [March 1, 2023, 9:31pm UTC](https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783/3 "2023-03-01T21:31:05Z")
Thanks for your reply – no humidifer.
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### Author:  [@timh](https://community.purpleair.com/u/timh)
#### Post date: [March 2, 2023, 9:22pm UTC](https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783/4 "2023-03-02T21:22:40Z")
> **[Sources of Indoor Particulate Matter (PM) | US EPA](https://www.epa.gov/indoor-air-quality-iaq/sources-indoor-particulate-matter-pm)**
>
> Learn about the many sources of Particulate Matter indoors and actions you can take to reduce or control them.
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### Author:  [@mpurple](https://community.purpleair.com/u/mpurple)
#### Post date: [March 3, 2023, 1:59am UTC](https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783/5 "2023-03-03T01:59:57Z")
That’s a really interesting list thanks for sharing. Given that there are clear spikes among wide valleys, I’ll be interested to continue to track. I’m guessing it’s either explained by cooking or pets, based on the list.
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### Author:  [@Tom\_Munnecke](https://community.purpleair.com/u/Tom_Munnecke)
#### Post date: [September 13, 2023, 9:00pm UTC](https://community.purpleair.com/t/reasons-for-exceptionaly-high-indoor-readings/3783/6 "2023-09-13T21:00:16Z")
I had similar spikes to that when I used my gas stove in my house. I didn’t think the stove would put out PM2.5 pollution, but it was pretty dramatic. The went away (mostly) when we replaced the gas stove with an electric induction range.