Why is important to have Indoor and Outdoor AQ Monitors

I have been monitoring air quality indoors and outdoors for a long time now but sometimes when the air quality is acceptable and good we forget the value of having air quality monitors inside and outside the house.

The story

On October 4th, a neighbor of mine decided that it was time to start burning garbage in an open area near my apartment and his. He was clever though, as he started burning stuff from plastic to wood at late midnight at 1:00 and 5:00 when everybody sleeps. I was sleeping too, but my air quality monitors are always monitoring the environment around me.

He did that for three nights in a row, and I was unfortunate because the weather conditions didn’t help the situation at all. No wind and no rain. The problem was that the smoke he emitted wasn’t moving at all and stayed in the neighborhood for hours. As a result, I was stuck inside with all the windows closed and CO2 concentration increasing constantly and steadily.

I knew I couldn’t do physical exercise as I will produce more CO2 so I went out to run. In an experiment I did, I was able alone to fill the 60 square meter apartment with CO2 from 600ppm to 1500ppm in 12 hours, by sleeping and working on my computer.

I was constantly watching the air quality outdoors and waiting patiently for PM2.5 and PM10 to drop to safe levels in order to open the windows and allow fresh air into the house and dilute CO2 concentrations.

I am a Greek guy who lives in Spain so I was waiting to see the reaction of the rest of the neighbors in order to act, accordingly, until I realise that they are not going to do anything as their ignorance will win the obvious move to notify one of the emergency services like the firefights or the police.

So in the morning of October 7th, I called the firefighters, the conversations was like this:

  • Hi, someone is burning garbage at night, 3 nights in a row, could you please come here and put it off completely and investigate the matter?
  • Is there an active fire?
  • Not right now, but there are fumes and unsafe concentrations of particles in the air plus the toxic smell of the burning garbage.
  • We can’t come unless there is a fire.
  • So you expect me to go out with a bucket of water and have a fight with the neighbor?
  • Ok, I will speak to my supervisor and we will see what we can do.
  • Ok, I will be waiting for your response.

Finally, they came, and they called me, and I explained to them once more what was happening at night. I don’t think they did something, but I think the neighbor saw them, and that was enough for me because since then, coincidentally, he stopped burning garbage.


I have many followers that are fighting with neighbors about BBQs or open fires or wood stoves, and I completely understand them. Call the authorities and create noise about it, don’t take as an answer that they can’t do anything. We have the right to breathe clean air because there are laws in most countries.

Air quality monitors help us see the air and quantify pollution. They also help us mitigate pollution and manage the air we breathe like in my case, I was able to monitor the indoor CO2 and outdoor PM concentrations to make the appropriate decisions in order to ensure safe indoor air.


3 thoughts on “Why is important to have Indoor and Outdoor AQ Monitors

  1. I know this all to well. Here in Northern Thailand people tend to do a lot of outside burning (rubbish, crop residuals, leaves, cooking etc) and I can see these spikes nearly every day on our outside sensor.
    Regarding the CO2 concentrations, we solved this by installing fresh air positive pressure systems that bring in HEPA filtered fresh air from outside. During the smokey season here in March/April I run on my treadmill inside for one hour and our positive pressure system keeps the PM2.5 at zero and CO2 below 1000.

    Liked by 1 person

  2. […] There is a great relationship between both environments as we exchange air. We need to ventilate indoor air to dilute some chemicals and CO2 that may build up. A scientific study has demonstrated that without a filtration system in the air exchange system, buildings tend to have 50% of the pollutants present in the ambient air. For example, if outdoors the mass concentration of PM2.5 is 100μg/m3, indoors will be 50μg/m3, which is ten times above WHO air quality guidelines of 5μg/m3. If you want to learn more read a past article on mine here. […]


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s