Risk From Ozone: We’re No. 1

“Southland on Course to Reclaim U.S. Smog Title” (Sept. 26) says Houston and Los Angeles have traded back and forth the title of the nation’s smoggiest city. L.A. has, in fact, always had the worst air pollution. Air regulators typically report the total number of days in which at least one of dozens of monitoring locations in their region exceed the federal ozone standard. In 2001, as of Sept. 24, this number is 35 for L.A. and 26 for Houston, reversing last year’s “standings.”

But these numbers have nothing to do with people’s actual health risk, because no single location in either region has anywhere near this many high ozone days. For example, Crestline, the smoggiest place in L.A., had 27 ozone violations, while Houston’s worst location had nine. The smoggiest location tracks real health risk, and L.A. has always topped Houston by this measure.

Joel Schwartz

Director, Air Quality Project

Reason Public Policy Institute

Los Angeles