Prescott's air quality (Phoenix, Flagstaff: air pollution, cars, rating)

[lostsoul62]

Prescott's is rated as the third cleanest air city in the US but what about the ozone which isn't mentioned in deterring air quality when rating cities for clean air. There are a lot of people and cars up there so I wonder how good the air really is?

[BriansPerspective]

City Data has some ozone info in their city profiles, but the data is seriously suspect. Take a look at:
http://www.city-data.com/city/Prescott-Arizona.html and
http://www.city-data.com/city/Phoenix-Arizona.html

Click the Ozone button on the Air Pollution and Air Quaily Trends graphs. Prescott only has two years recorded: 2008 and 2009. The ozone dropped from about 55 ppb to 25 ppb for Prescott. Notice that the national average values also dropped from about 37 ppb to 22 ppb. Now look at the Phoenix graph. There are ten years worth of data. The ozone levels jump and dive from 45 ppb to 15 ppb, presumably on some summer/winter cycle. Now look at the national average for 2008 and 2009 on the Phoenix graph. Notice that it also jumps and dives in step with the Phoenix data. So, how can the national average data jump and dive on onen graph and yet show a slow downward trend on another graph. Obviously the national average ozone data is incorrect somehow. This leads me to question the accuracy of the city ozone data as well.

I also suspect that the recorded ozone data (like rainfall data) is dependent on the locations of the sensors. I do not know how quickly ozones diffuses or how well it mixes. Those factors would have a significant effect on both the accuracy of the data and the ability to extrapolate the data across a region.

[wretched wrench]

My unscientifically-calibrated lungs tell me that Prescott air is way better than Phoenix.

With almost every visit to Phoenix.

[BriansPerspective]

I am further questioning any measurement of ozone. Click on the any of the measurement points on the EPA map at: Ground-level Ozone | AirTrends | Air & Radiation | EPA They all hover around 70 ppb (0.07 ppm). I.e., Phoenix and LA show the same measurement as Flagstaff. Unfortunately, the Prescott point has no data (the graph comes up blank).

Upon reading websites for the makers of ozone measuring devices, they indicate that measuring ozone at levels below 300 ppb is challenging and has several factors that skew results. See: Aeroqual - for accurate measuring of ozone at very low concentration levels