In China, food scares put Mao's self-sufficiency goal at risk
Inspectors in Guangzhou collected samples from 18 locations in the city and found cadmium levels in eight exceeded the national standard of 0.2 micrograms per kilogram, with some as high as 0.4 mg/kg, the local government said late last week.
Though experts insisted the health risks were very low and China's standards for rice, its staple food, are far higher than the rest of the world, authorities swiftly came under attack from users of China's popular microblogging service Weibo. Guangzhou was eventually compelled to reveal the tainted rice originated from central China's Hunan province, the country's biggest rice-producing region.
Hunan produces 30 million tonnes of rice a year, 15 percent of the national crop, but it is also a big miner of nonferrous metals and toxic elements such as arsenic and cadmium. In many cases, wastewater run-offs from the mines are used directly to irrigate farmland, and tailings also tend to be badly managed.
Yin Lihui, an official with the provincial environmental protection administration, told state media that nonferrous metals mining in Hunan has caused heavy pollution in a region dubbed the "home of rice and fish".
"We call it 'integrated food and mining complexes' - basically food production and mining happening at the same place together, and this isn't rational," said Chen Nengchang, a researcher at the Guangdong Institute of Environmental and Soil Sciences who works on projects to rehabilitate land damaged by mining and heavy metal pollution. "The problem is that China has a big population and scarce land and soil, so we need to figure out another way of dealing with this."
To ensure food supplies, China has said it will limit the amount of land given to development. This will not only require the government to declare farmland out of bounds to industry, but also require ruined wasteland to be returned to life. Some researchers say as much as 70 percent of China's farmland is affected by pollution. After decades of contamination, land must be restored if it's to return to agriculture.
That takes time and money. High real estate prices in urban areas make it relatively easy to find the money to clean up land contaminated by chemical or heavy metal waste, but cleaning up the countryside is a greater challenge, said Richard Fuller, president of the Blacksmith Institute, a New York-based non-profit group that helps clean up polluted sites in China and elsewhere. "There are solutions for the majority of damaged sites but it's going to take time, technology and money."