Well studies like this are often directed at policymakers, who actually can do something about it.
Big spikes in soft money group spending in 22 and 24 elections...
https://www.opensecrets.org/industries/indus?cycle=2024&ind=...
This thing says roadside ppm2.5 is down from 17 to 8 in central where I live https://www.theguardian.com/environment/2025/mar/07/london-a...