China’s first public soil survey since 1996 shows that almost a quarter of the margin between the country’s total arable land and the “red line” minimum needed for food security has been eroded by pollution. From Xinhua:

According to the results of the second national land survey released on Monday, China’s arable land totaled 2.03 billion mu (about 135.4 million hectares) at the end of 2012, 227 million mu more than the “bottom line” set by the government to ensure food security.

[…] The three-year survey showed that China’s per capita arable land area shrank to 1.52 mu by the end of 2009, far below the world average of 3.38 mu, Wang said.

[…] To make the situation worse, soil pollution is also hurting farming, with around 50 million mu — about 2 percent of the country’s arable land — too polluted with heavy metals or other waste to be used for growing food, according to Wang. [Source]