There isn’t a reader who reads this blog regularly who does not now know that the San Joaquin Valley of California is this nation’s most air-polluted trouble spot – irrespective of whether such had prior knowledge of this or not – a pollution trouble spot even more so than Los Angeles in the south state which was itself once this country’s epicenter for air pollution. Air pollution worse in the Valley than in Los Angeles? Really? Yes, really! I’ll get to the specifics on this in a moment.
Now think about this for a moment. Leaders at the local air district have been telling the Valley citizenry for years how mobile sources are responsible for the bulk of the Valley’s air-pollution problem – I’ve read where pollution in this region from mobile sources is as much as 80 percent. It doesn’t help that geography, topography and meteorology can as well be blamed for bad air being trapped in California’s mid-section, often for days and sometimes weeks if not months at a time. In getting air here to a state of healthier repair it is going to take serious help (read: “work” – hard work and lots of it)!
How Valley moves
Just yesterday, I learned by reading an article in The Fresno Bee that not only has driving increased (at least in Fresno and Tulare counties, anyway), but so too has roadway capacity in the form of more miles of roads and highways being added, while public transit use has fallen off, in Fresno County, that is.
In fact, in Fresno County alone, miles driven went from 19.3 million miles per day to 23 million from 2000 to 2013, a rise of 19 percent. Meanwhile, road miles during this same time went from 6,987 to 7,167.
The story is little different in Tulare County, a neighboring county to Fresno’s south. There, vehicle miles traveled jumped from 8.9 million to 9.9 million, or an increase of 10.8 percent. Add to this that the average time it took drivers in Tulare County to commute to work one way was 21.1 minutes in 2013. Though public transit use rose by just one-tenth of a percentage point, miles of Tulare County roadway went from 4,728 in 2000 to 4,906 in 2013.
Many residing here won’t see this as a problem as commuting to work one way on average consumes just 20.5 minutes. Many as well won’t see the downturn in workers commuting by public transit as any big deal. They might if congestion was an issue. But, alas, it’s not. This, however, does not change the fact that free-flowing traffic existing today might become congested or gridlocked traffic tomorrow considering the San Joaquin Valley is expected to grow in population from its current 4 million to as many as 9-to-12 million by 2050, that’s two-and-a-quarter to 3 times as much. If roadway lane mileage doesn’t keep pace, what then?
Then there is what’s called: “induced demand.” That is, as extra roadway capacity is added, the number of vehicle miles traveled also goes up. And, when travel increases, especially if the majority of that travel is in gasoline-fueled motor vehicles, well, guess what: the concentration of pollution in the air also jumps. Transit could lessen some of the impact. But the reality that transit-bus commuting in this area has dropped from 1.7 percent to just 1.1 percent doesn’t bode well. It may be time to consider something other than roadway-based transit bus service as an effective solution. It may be time to look at light rail.
SJV the nation’s air pollution hot spot
Those who would believe that the South Coast Air Basin is the epicenter for polluted air in the United States would be wrong. The basin includes all of Orange County, and the non-desert portions of Los Angeles, Riverside and San Bernardino counties.
![320px-Los_Angeles_Basin_JPLLandsat[1]](https://alankandel.scienceblog.com/files/2012/12/320px-Los_Angeles_Basin_JPLLandsat1.jpg)
Covering an area in size no smaller than 30,000 square miles, housing no fewer than 17 million people, the South Coast air basin does have its share of pollution. But, air-pollution-wise, the San Joaquin Valley, at around 24,000 square miles in area with its approximately 4 million residents is the dirty air king. Region versus region, per-San-Joaquin-Valley-square-mile, an average 166 and two-thirds people reside while an average 566 and two-thirds persons per square mile live in the South Coast air basin – that’s 400 more people per square mile.
What this tells me is that per given area, the South Coast region has a far higher concentration of people whereas the San Joaquin Valley, with far fewer people, has a far higher concentration of air pollution per person. Despite this, the concentration of pollution in the air, South Coast compared to San Joaquin Valley, isn’t that much different. And, in effect, what this means is that if the Valley had a population similar to that of the South Coast region, the concentration of pollution in the air would be considerably higher. Alternatively, without air-cleansing Pacific Ocean breezes to help filter area air in the Southland, that location would no doubt be this country’s worst place for dirty air.
Lower image above: NASA
– Alan Kandel