BEIJING -- China will conduct its first nationwide survey to track down the sources of pollution in its latest anti-pollution campaign.

All factories, stock farms and urban institutions which release sewage, rubbish and medical waste will be surveyed.

The survey will be carried out from December 31, 2007 by the State Council and will last for one year. The State Environmental Protection Administration (SEPA) will gather and then publish the results in 2009.

China was ranked the world's worst sulphur dioxide emitter in 2005 with more than 25.5 million tons, 27 percent more than in 2000.

According to its 11th Five-Year Plan (2006-2010), China aims to reduce the discharge of key pollutants including sulphur dioxide (SO2) by 10 percent by 2010.

However, SEPA statistics show that SO2 emissions in the first half of 2006 were up 5.8 percent on last year and one third of the country's territory was affected by acid rain last year.