Dairies cause more smog than cars, according to the San Joaquin Valley air district. Recent science shows milk cows produce at least 60 percent more smog-forming chemicals than previous estimates, which were based on aging studies, valley air officials say. And that's "likely to be an underestimate," said Rick McVaigh, director of permit services for the air district, which released a draft pollution-per-cow estimate Monday. Dairy industry representatives are outraged that the district would rely on incomplete and irrelevant science, they say. "It's unbelievable what they've come up with," said Michael Boccadoro, spokesman for a dairy lobbying group known as...