Steve - I'd love to hear proof that it's wrong, because I'm very concerned about the air quality in Modesto. Not just this report, but all reports give Modesto a very bad air quality rating.
To start .. some background. For the last 10 years about half of my professional work has involved air quality, with particular work on estimating emissions of air pollutants, monitoring impacts, modeling the impacts of air pollutant emissions, and conducting ambient impacts assessments of air pollutant emissions. So this stuff is right up my alley. Frankly, I would be professionally embarrassed to have my name associated with a report such as this.
The methodology is riddled with problems. I'll just address two that individually completely invalidate the whole exercise.
First is that the TRI data source used accounts for less than one-third of the emissions of air toxics. It's like doing a study of the size and breadth of timeshare exchanging, while pretending that RCI doesn't exist.
So what are the missing sources of toxics? Vehicle emissions (particularly diesel emissions) and fireplaces and wood stoves. For example, the Puget Sound area ranks in the top 5% of urban areas in the USA for air toxics according to EPA. Within the Puget Sounda area, diesel exhaust accounts for more than 70% of air toxics emissions, and wood smoke is the next biggest at 6%. Drawing inferences when you leave out more than 3/4 of the emissions is laughable. The technical people who worked with USA Today on the study ought to be fully aware of that. If they were and went ahead anyway, shame on them. If they didn't then their credibility is out the window.
+++++
The second major issue is that the TRI inventory simply gives a location and reported emission rate. It makes a big difference whether something is emitted from a stack - at elevation, with exit velocity and elevated temperature - versus something that is released at ground level in a diffuse manner and with little bouyancy. There is no way they could obtain the information to conduct proper dispersion modeling using the TRI data source. There are other data sources with that information, but the fact that they used the TRI data source for that purpose totally impeaches the results.
+++++++
Now note what you have here. The emission inventory omits 75% of the toxics emitted. Further the toxics that are not included also happen to be released under the conditions that create the highest impacts. Diffuse sources, at ground level (wheere people breathe the air directly) and right next to our schools and houses.
And none of that is included in the modeling.
+++++++
If you're concerned about air toxics, it's seldom that industrial stacks are what you should be concerned about. You should first look at the vehicles that you and other people drive.
You meet the enemy every time you look in the mirror in the morning.