Published Monday July 10, 2017

Air Pollution


In Utah, each county has an air pollution monitor that takes hourly readings and reports back the amount of particulates there are in the air, as well as ozone concentrations.

While these sensors are fine and good, sometimes they are broken and don’t report back data for days at a time.

Even if every one of these sensors worked perfectly all the time, there is only a hand full of them and that doesn’t paint a very high resolution picture of how clean the air really is.


Here is an 14x18 block picture of Abraham Lincoln. It has 36 times the resolution of Utah's current air quality sensor array. 

It’s kind of like looking at a photo of the entire state of Utah that is only 7 pixels. You get an accurate picture in the vicinity around each air sensor but 100 feet away, the air could be something else entirely different.

What we need is a vast array of air quality sensors, at least 40 times as many.

Enter Purple Air:

Iain Hueton started a company called PurpleAir that makes low cost air quality sensors. These have been deployed around the world with the largest concentration of them along the Wasatch front. While they are not as precise as a more expensive air quality sensor, they are able to report data every few seconds instead of every hour. Each sensor actually has redundant sensors inside and the final reading is based on an algorithm of the two sensors.

Each Purple air sensor automatically reports its data and is projected onto an on-line map. Using the whole collection of air quality sensors, you can at-a- glance get a better picture of the air quality in your city and know what neighborhoods have healthy air and which ones don’t.

Wanting to know what the air in my literal backyard is doing, I bought and installed my own PurpleAir monitor.
Initially I set up the sensor inside the house just to make sure it was working. On that day, the outdoor air quality was very poor along the Wasatch front, (above 150 for PM2.5). However, inside my home the air quality sensor was reading only 1 for PM2.5. Wow really? Just 1 for PM2.5? That is really clean air inside the house. Thanks to the MERV 13 air filter in our ground loop heat-pump, we are breathing very clean, healthy air.

At first I didn’t believe this reading. But then I moved the sensor outside and after giving it a few minutes to acclimatize, its reading was comparable to a Purple air sensor a few miles away and the official government, air quality station 10 miles away. 

It’s amazing that by just tracking air quality over time, I can infer with almost certain accuracy when all the parents are zipping by, shuttling their kids to school in the morning, or when the local church goers are whizzing past, rushing in their vehicles to get to church. Both of these activities temporally elevate the pollution levels in the air by my house for about 10 minutes.

While the medical harm of breathing the air outside during these times is equivalent to taking a couple drags on a single cigarette, it’s good to know when it is best to avoid going outside.

One night a few months ago we built a fire in the backyard and roasted hot-dogs and marshmallows. Out of curiosity I pulled up the air quality monitor on the PurpleAir website.  The air quality in our backyard spiked from single digits to over 154 for PM2.5. Wow, who knew that a friendly backyard fire was so polluting.

Maybe if more people get these monitors we can raise awareness of the poor air quality in our valley and finally convince the legislatures of our state to do something about it. 

Ways to reduce air pollution:

  • Make public transportation free on bad air days, or during bad inversion seasons when air pollution gets trapped in the valley for weeks at a time. 
  • Forbid gasoline refineries and other polluting industries residing in the valley to operate whenever the local air quality exceeds 50 for PM2.5. 
  • Just quit the nasty habit all together, ween yourself off of the gasoline teat and only drive electric cars.
If everyone did this, it would eliminate over 50% of our local air pollution.
Taking it a step further, 
  • Add more insulation and air seal your home. 
  • Replace your natural gas water heater with an ultra-low NOx variety or ditch gas and get an electric heat-pump one. 
  • Don't burn wood, especially during bad-air days. If you have to burn wood, get a catalytic wood burning stove that burns the wood particulates completely. 
  • Replace your old inefficient natural gas furnace with a 97% efficient one. Or better yet, ditch natural gas all-together and go with a hyper-efficient, electric ground-loop heat pump
  • Get solar panels and power your house and electric vehicles from them. 
If everyone did this, millions of human lives would be saved and we would all be much healthier.