Chinese crops: a soiled image? (Agriculture).

As China aims to boost its agricultural production, its farmers' own zeal may prove to be the biggest obstacle to increasing exports. In the industrialized south, particularly, where agrochemicals are more readily available, farmers use such great amounts that consumers are growing leery of health risks.

Between 1949 and 1995, Chinas application of inorganic fertilizers soared, finally slowing in recent years to rates comparable with its more industrialized neighbors. But researchers at The Hong Kong Polytechnic University say farmers in Guangdong province still apply an estimated 800 kg/ha, or five times the world average. In that region's Pearl River Delta, some experts suspect farm pesticide residue of a role in nearly extinguishing the local pink dolphins.

In the August 2002 issue of Environmental Pollution, researchers from Hong Kong Polytechnic and the Guangzhou Institute of Geochemistry report mean cadmium concentrations of 0.58 mg/kg in the soil of farms growing cash crops. Associated with pesticides and fertilizers, cadmium is a known human carcinogen, and chronic long-term ingestional exposure is associated with kidney damage and osteoporosis. Although scientists don't know how much food exposure those concentrations translate into, the paper notes that continuous heavy application of agrochemicals and other soil amendments could exacerbate the accumulation of heavy metals in agricultural soils over time, as well as increase the amount that runs off the soil. Another report, in the 25 October 2001 issue of the Far Eastern Economic Review, states that China is the only country seeking a waiver to use DDT "as a general intermediate" and not just in the low concentrations used for malaria prevention. Chinese newspapers have reported high concentrations of DDT in some food items.

Economics shapes farmers' use of chemicals, says Alex Lu, a senior research scientist at the University of Washingtons Department of Environmental Health: "While some new agricultural chemicals are safer and more environmentally friendly, old nasty stuff like DDT is effective at a much lower price."

Robert Crooks, lead author of the 2001 World Bank report China: Air, Land, and Water--Environmental Priorities for a New Millennium, says Chinese farmers--like farmers around the world want clear evidence that chemicals can knock weeds down dead. Until they get concrete information about health risks, those risks get low priority.

Various sources agree that the Chinese government's control over farmer pesticide practices is loosening. Where policy fails, however, market incentives and education may help. On 16 February 2002, the South China Morning Post noted that foreign fruits were becoming more popular among Chinese consumers, and that imports of Chinese fruits in other countries trailed expectations by nearly 10-fold. The paper cited consumer concerns over heavy pesticide use as the problem.

"The more cases of exports being rejected due to contamination, the more likely the government will be to tighten up regulations and enforcement," says Crooks. "They are aware of the problem and have begun to take steps in the right direction."