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Ozone and our food


There's been a lot of buzz about China's filthy air and its effects on the health and performance of the world's Olympic athletes, but, more disturbing to me, rampant air pollution can affect the yields and quality of the world's food supply, too. Now, although more stringent emissions standards on cars have reduced short periods of high ozone levels, our “background” ozone levels -- the average annual concentrations of the gas in the atmosphere -- have actually increased. In a recent news release, William Manning of the University of Massachusetts Amherst suggests, in part, we have Asia to thank for that, because polluted air masses from the region are making their way to North America and Europe.

"Background levels [of ozone] are now between 20 and 45 parts per billion in Europe and the United States, and are expected to increase to between 42 and 84 parts per billion by 2100," Manning, a professor of plant, soil, and insect sciences, states. (That doesn't bode well for crops such as broccoli, soybeans, cabbage, and wheat, all of which are particularly sensitive to ozone.) After studying the effects of ozone levels on oilseed plants growing in China's Yangtze Delta, Manning and other researchers noticed a 10 to 20 percent decline in the size and weight of crop yields. This summer, Manning is conducting plant trials in Pioneer Valley in Massachusetts, since air pollution drifting in from Washington, D.C. and New York City regularly elevate the Massachusetts area's background ozone levels. Along with a control group, plants grown in open fields will be treated with an ozone-blocking compound to determine the extent to which ozone is to blame for poor plant performance.

And then? Even if scientists are able to determine how much ozone it might take to threaten the global food supply, our own need to burn fossil fuels -- and, especially, Asia's explosive economic growth -- simply will not be suppressed. As such, science will have to scramble for a solution to mitigate ozone damage, and farmers, meanwhile, can add a new worry to their collective list. Insect pests, sundry plant diseases, and drought, make room. I fear ozone damage is here to stay.