In response to "Air in San Joaquin Valley cities among nation's worst" (April 24): Oh, joy! Another story that wants government to put the screws to a region that's already being crushed by air quality regulations.
Geography plays an important part when it comes to air quality. The San Joaquin Valley is an elongated bowl with one opening along its western ridge. The delta breeze, a blessing for valley residents during the summer, is also a curse as the onshore flow of air carries the Bay Area's pollution into the San Joaquin Valley.
This accounts for about a third of our dirty air. If there's a need to crack down on emissions, then look to the Bay Area first.