The caller wanted me to explain how the New York Times was wrong in 1999 about the worst smog traps in America — which were Los Angeles and Houston, as the Times told the story.
I had written last month about the subject, and it's a great idea to explain it, because the Times really was not wrong.
The newspaper understandably missed the story, writing about the federal one-hour ozone standard instead of looking at the eight-hour standard.
Hands down, LA and Houston had the highest ozone peaks in 1999. And LA had a lot more one-hour exceedances than any place in the country that year.
But the San Joaquin Valley was much worse than LA in sheer numbers of eight-hour exceedances.
LA exceeded the eight-hour threshold 120 times in summer of 1999. The Valley did it 153 times. It means people here were exposed to dirty air here longer than people in LA.
Why didn't the New York Times and the Los Angeles Times write about the Valley? Actually, nobody did. The reason is that the eight-hour standard had only been established two years earlier.
When a new standard is adopted, it takes years for the federal government to classify each area of the country, enforce the rules and report all the numbers.
The U.S. Environmental Protection Agency then updated the eight-hour standard in 2008, making it more stringent.
So filling in the blanks: The exceedance numbers I quoted earlier in this item are the 2008 standard applied backward to 1999. The exceedances weren't even known in 1999.
The media really had no chance to report that the Valley was having so much trouble. The Valley only had 25 exceedances of the one-hour standard that year. That's all the media could report.
I didn't write a single word about it at the time, even though I was following air quality in 1999.
Now, the Valley's air problem is widely known. That's important. The public knowledge is a powerful influence on leaders who hold federal purse strings.
The Valley's air cleanup has made progress over the last 15 years. Ozone concentration and numbers of exceedances have dropped as money has been invested in cleaner diesel engines and other technology.
But it is still important for the people here to know about the air. The Valley and Southern California remain the two dirtiest air basins in the country. People need to take precautions whenever pollution spikes in these two regions.