I'm in Pittsburgh's exurbs and I'm seeing more monitors, like in Penn Township, on that map.

Protect PT gave me a Purple Air monitor and installed it my home.

Interestingly, they told me they offered to buy and install these monitors at local public schools, but many schools refused them. If it turns out there's an air quality issue at the school, the school district has to address it, and it's cheaper to ignore it.

https://www.protectpt.org/