Assess Your Air Quality With This Mashup of Sensors

I was checking the air quality at my California abode the other day, and the first website I went to said the Air Quality Index was a lovely 40 or so. That seemed strange, given how smoky it was outside — so I tried another site: 400+. That also seemed strange, since it didn’t quite look a Dune trailer outside, either.

Why the discrepancy? I was using PurpleAir, a website I’ve talked about before, as well as AirNow, and they both take different approaches to measuring the air quality in a particular area. As SFGate reports:

“PurpleAir has hundreds of monitors in the area providing real-time readings updated every 10 minutes. AirNow’s sensors are more accurate, state-regulated and calibrated regularly by scientists. But there are far fewer monitors than PurpleAir, and readings are shown hourly, allowing gaps in coverage and the potential for outdated readings.”

The solution? A mashup, of course.

[referenced id=”967981″ url=”https://www.lifehacker.com.au/2020/08/use-these-apps-to-see-if-your-air-quality-index-sucks-outside/” thumb=”https://www.gizmodo.com.au/wp-content/uploads/sites/4/2020/08/28/vv8ejlxjnhqxf8bjetiw-300×169.png” title=”Use These Apps to See if Your Air Quality Index Sucks Outside” excerpt=”I’m writing this from lovely, sunny California — at least, I think it’s sunny, because smoke from the apocalypse wildfires around Silicon Valley has been billowing around the area for about a week or so. The quirky thing about this ecological disaster is that there are sometimes days of, “oh…”]

The Environmental Protection Agency and the U.S. Forest Service have launched a new version of the “Fire and Smoke Map” on AirNow that combines data from said service with PurpleAir. That doesn’t necessarily mean that any of the numbers you’re looking at are going to be entirely accurate, but it at least gives you an easier way to come to your own conclusions (or ignore both numbers entirely and just go, “Well, the air is terrible today.”)

As the site’s announcement reads:

“EPA and USFS are conducting a pilot project to add data from low-cost sensors to the Fire and Smoke map. While these sensors don’t meet the rigorous standards required for regulatory monitors, they can help you get a picture of air quality nearest you especially when wildfire smoke is in your area. Use the map layer icon in the upper righthand corner of the map to turn on information from AirNow monitors, USFS temporary monitors, and sensors. EPA and USFS may update the sensor map layer several times during the pilot project, as we respond to feedback and work to improve the map.”

On said map, PurpleAir’s sensors show up as smalls squares, whereas AirNow’s sensors show up as circles. There shouldn’t be a ton of discrepancy between the sensors, but at least you’ll now be able to see what that discrepancy is, if it exists. And you can then make your own value judgment as to whether a nearby sensor is probably acting up or not (if your location’s Air Quality Index is great, for example, but all the nearby sensors around you suggest otherwise).

You can also click on any sensor to get extra details, including a helpful chart that shows you its readings over the last few days:

You’ll note, too, that this picture has PurpleAir’s sensor showing up as “green,” even though locations around it indicate the air is a hellhole. I would be willing to bet that this “everything is fine!” sensor is messing up. And thanks to this mashup site, you have a little extra data you can use to make that determination yourself.

Or you could, you know, just not spend a lot of time outside if it smells like you’re standing next to a bonfire. That also works.