[rootusrootus]

Five tons sounds like a lot. But on the other hand, the Los Angeles basin sounds pretty big. (a quick check suggests it is about 1200 square miles)

The AQI there looks good.

[pajko]

Don't assume that the distribution is uniform.

[rootusrootus]

I'm only making the assumptions that I can given what little information is contained in the original statement. We would need better quality information to make any further inferences.

[dv_dt]

Aqi doesn't measure this, does it?

[rootusrootus]

Is tire particulate too big to show up in the AQI measurement? If so, does it fall out of the air so fast that it isn't really a problem?

[dv_dt]

The Aqi is an index which is guided only in part by Particulate Matter measurements. The index part was definitely designed before microplastics research without knowledge or regard to is effects. Pm100 doesnt register them, PM2.5 may register them, but grossly with any other particulates of that size - so you dont know if the captured particulates are microplastics or something else or something in between

[barfingclouds]

As someone who lived in LA, the air quality is usually moderate or above, like all the time. I consider that not good