China's Air Pollution Chokes Crop Growth
Monastersky, R., Science News
With China's economy and population expanding at breakneck speed, its infamous air-pollution problems have started to claim new victims. Data collected at rural Chinese sites indicate that ozone pollution has already reached the point where it's harming agriculture--raising questions about whether the world's fastest developing country will be able to feed itself in the next century.
"There has been a lot of discussion of whether China can meet its future food demands, but there has been very little discussion of how regional environmental degradation is affecting agriculture there," says William L. Chameides of the Georgia Institute of Technology in Atlanta, who led the study.
When ozone, a highly reactive gas, builds up in the lowest layer of the atmosphere, it harms plants and animals. The pollutant forms when hydrocarbons and nitrogen oxides mingle in the air and get cooked by sunlight. Both these ingredients come from the incomplete combustion of fossil fuels. Hydrocarbons also are released by vegetation.
In a collaboration with Chinese researchers, Chameides and his U.S. team analyzed ozone measurements made at four rural sites in China during 1994 and 1995. These are the first systematic ozone readings taken outside cities in China, according to the researchers.
They found the highest pollutant concentrations at two places: an agricultural town called Linan, near the coastal city of Hangzhou, and a part of Hong Kong Island upwind of the city. At both spots, ozone often exceeded 60 parts per billion, an approximate threshold for harmful effects. …