China looks for answers to pollution scandal
22 March 2013 Last updated at 09:27 GMT
There is growing concern about the safety of China's drinking water after the number of dead pigs found in rivers around Shanghai increased to almost 14,000.
There has been no word from the authorities about the cause of the deaths.
The scandal is the latest environmental issue to affect China, following recent record smog levels in Beijing, and water and air pollution in villages.
John Sudworth reports.