Air quality reporting on iOS

The problem here is twofold.<p>First, many countries have their own laws and policies regarding air quality exposure. Often times these regulations use metrics about time-average exposure (e.g. the annual average 8-hr maximum ozone concentration) and can&#x27;t trivially be converted between agencies. It causes very negative user experiences when your air quality summary disagrees with what a regulatory agency is putting out to the public due to a measurement technicality - much easier just to localize the data in the same way you&#x27;d localize the rest of the UI.<p>Second, we&#x27;re stuck with AQI and similar indices because air quality is a multi-faceted problem with different components measured wildly differently. For instance, PM2.5 and PM10 are typically reported in ug&#x2F;m^3 - but who actually knows what these measurements mean? What&#x27;s the difference between 15 and 30 ug&#x2F;m^3? It&#x27;s very far outside of the experiences that many individuals have, so end users really struggle to interpret these values, even when you translate them into simple &quot;low&quot;&#x2F;&quot;medium&quot;&#x2F;&quot;high&quot; categories. Then of course gas-phase pollutants are typically reported in volume concentrations like parts-per-billion or parts-per-million. Aside from the fact that these values are very commonly misinterpreted as much smaller than they actually are, the difference in units adds another bit of complexity into users interpreting what they&#x27;re seeing.<p>A well-designed air quality index could factor our all these challenges. I definitely h&#x2F;t Breezometer for their attempts there, even if it is generally poorly received. But it&#x27;s a very challenging problem no matter how you slice it.

Of interest to folks looking at this post -- Chris Said has a deeper dive on US air quality metrics and their provenance, <a href="https:&#x2F;&#x2F;chris-said.io&#x2F;2023&#x2F;06&#x2F;19&#x2F;the-air-quality-index-doesnt-make-any-sense&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;chris-said.io&#x2F;2023&#x2F;06&#x2F;19&#x2F;the-air-quality-index-doesn...</a>.<p>The attempt to make things easy to interpret using a nice relative scale ends up in the end make them very opaque to interpret the number itself in any meaningful way.

&gt;&gt; I noticed something strange in the iOS weather app: The air quality index seems to be defined relative to the country from which one accesses the air quality map.<p>Yup. And if you look closely the underlying map also sometimes changes based on which country one is standing in (Crimea&#x2F;Taiwan). Services like iOS are not scientific but consumer and government-focused services. They exist to appease a host of interested parties, not to render dispassionate information.

Interesting. This seems like the reasonable way to do it.<p>What global scale would you pick otherwise? And would it be sensitive enough to show gradients in the least&#x2F;most polluted countries and cities or would it just fill them in with one color?

I should be able to translate what my local government&#x2F;news says about air quality, just like any other portion of the weather forecast (C, F, etc).<p>Information based on user locality seems like an excellent design.

I live in the Netherlands, I&#x27;ve tried to get this air quality report out of the iOS app, so have others. It just tells me every day the air is shit. I mean when you tap on it, it tells you not to exercise outside for example. It&#x27;s rarely &quot;good&quot;, mostly it is &quot;insufficient&quot;, sometimes it&#x27;s &quot;very bad&quot;.<p>Is it really so bad? You don&#x27;t hear anything about it from other sources... Tapping on, one finds the main pollutant to be ozone, &quot;usually caused by traffic and it can be transported over large distances.&quot;<p>Idk what to think of this. Many people seem confused. Are we really in such poor air all the time?<p>Sometimes I bike through the fields in the morning, sniff the fresh humid air that has a coldness in it, I smell grass and flowers... Apple tells me: Insufficient (don&#x27;t bike to fast!) :(.<p>Maybe they are right, maybe they are forcing us to come to terms with the things we do to our air.

I&#x27;ve never ever seen air quality in iOS. Probably not available where I live. You guys at least, well, have it.

I have never understood how to interpret AQI in iOS. Confusingly, the UI will (edit: or at least used to?) say &quot;Air Quality: Low&quot; when what it means is that the pollution level is low (ie. air quality is high). Somewhat disappointing coming from Apple.

I&#x27;ve been using the PurpleAir website (map.purpleair.com) for many years now, mostly out of concern for heavy wildfire pollution and winter inversions vs personal outdoor+athletic activities; one interesting aspect is that you can buy your own sensor and thus join the community of local sensors for increased accuracy of measurements. They let you pick between various international standards and types of pollutants. They seem to have a dense network of sensors in North America, not sure about the rest of the world.

In Italy I have noticed that the air quality is usually considered bad only in places that actually have data. For a lot of the places that are considered good, checking the sources for them usually result in only 1 device.<p>It&#x27;s a nice to have certainly but I wish it was more consistent.

I&#x27;m also curious why there&#x27;s no data for countries like Belgium, Switzerland and Austria.

Yeah, I&#x27;ve noticed this too.<p>It looks like the air quality models that iOS Weather is using are integrated into a single system, and then that system is asked to render maps in any of the different regions&#x27; AQI systems.<p>Which means, as OP has observed, if you open the map from one region, and then navigate the map viewer to another region, you can see how the AQI scoring system from the first region would evaluate the second. Which is rather interesting.<p>Also fwiw I&#x27;ve reckoned that these AQI models are clearly highly algorithmic, extrapolating and synthesizing data where sensors are not available.

Somewhat related, Apple’s Air Quality data source (breezometer) is now owned by Google.<p>I wonder what Apple is going to do about it. Will it be just one of their data sources or are they going to acquire their own?

As a point of clarification, Apple&#x27;s AQ data is due to their licensing agreement with BreezoMeter (Israel). <a href="http:&#x2F;&#x2F;Breezometer.com" rel="nofollow noreferrer">http:&#x2F;&#x2F;Breezometer.com</a> As a data broker, they acquire&#x2F;license the data from a variety of sources and the sell the compiled data to licensees with customer-specific data unit (eg. USA = AQI (EPA std).

“I noticed something strange in the iOS weather app”<p>I’ve noticed that the weather app on my iOS, iPadOS, and watchOS all show differing forecasts with all 3 devices within 18” of each other. AQI is just one of the parts of the forecast that I just don’t pay attention too. Around here in the summer, it is always an alert saying don’t go outside

The air quality index displayed is based on the current location that you have set to view the weather. If you want to switch to a different scale: add a new saved location, switch to it, and the view the AQI map.

&#x27;This air quality level is known to cause cancer in California&#x27;

I didn&#x27;t know that there is actually any data for this view. With an Austrian iPhone the air quality map is always empty &quot;no data&quot;. Also for Germany and the Netherlands.

That’s why I like Air Matters. You can choose your scale

I mean tech is full of conflicting standards. (see relevant xkcd...)<p>In this particular case the actual values just happen to land on the edge of two colours in the scales with very different connotations - orange vs green.