Cows and chickens may explain Cache County's problem, but it probably has little to do with the smoke in Salt Lake or Utah counties, where fine particulates reached as high as 77.8 micrograms per cubic meter of air last week, according to a news story in this paper. Anything over 35 is unhealthy.

Getting to the heart of the problem is important. The worst thing politicians could do is to impose solutions that have no relation to the problem. Cars and trucks are obvious sources of problems. But before we impose odd-even drive days or special gas taxes during winter months, consider that one of the worst inversion winters was 1930-31, with 42 days of smog. That was almost identical to 2002-03, with 43.

I assume there were fewer cars here in 1930 than in 2002.

The main problem, of course, is geography. The valleys of northern Utah form bowls that lend themselves to temperature inversions, where high pressure traps cold air on valley floors, with warm air far above. That's a frustrating answer, of course.

Cars, factories, fireplaces, cows and chickens certainly add to the problem. There may be reasonable restrictions to consider. But the unfortunate truth is you can't outlaw geography.

Jay Evensen is editor of the Deseret News edito?rial page. E-mail: even@desnews.com. Visit his blog at www.deseretnews.com/blogs