April 21, 2010
Animal Feed, Not Automobiles, Makes The San Joaquin Valley A Smog Hotspot
A new study identifies cattle feed as a possible culprit in the long-standing mystery of why California's San Joaquin Valley "” a moderately-populated agricultural region "” has higher levels of ozone (one of the main ingredients in smog) than many densely-populated cities. The report, which explains how fermented cattle feed works with automotive exhausts in forming ozone, is in ACS' Environmental Science & Technology, a semi-monthly journal.
Michael Kleeman and colleagues note that high ozone levels in the San Joaquin Valley, which produces 10 percent of America's food, have puzzled scientists for years. Motor vehicles are the major source of smog elsewhere, but the Valley has fewer motor vehicles compared to big urban areas with similar levels of ozone. Suspicion thus fell on farming activities, and the new study investigated the role of fermented livestock feed.
Image Caption: Animal feed, not automotive exhaust, appears to be the major source of smog formation in California's San Joaquin Valley. Credit: iStock
On the Net:
- Article: Reactive Organic Gas Emissions from Livestock Feed Contribute Significantly to Ozone Production in Central California