Dealing with China's environmental challenge

After three decades of growth, the world's biggest country, China, faces a major challenge of dealing with environmental damage.

It is estimated that 20% of China's arable land is polluted with heavy metals, with 90% of groundwater said to be contaminated.

More Chinese are now at risk of being killed by air pollution than by smoking.

Carrie Gracie reports from Hunan Province in Central China on the country's search for sustainability.