The pollution density in north China's Songhua river, hit by a devastating toxic slick, is "sharply" down, state media reported Saturday.
The announcement was made by Zhou Shengxian, the newly-appointed leader of the nation's environmental watchdog who had flown in to see the extent of the damage in person, the Xinhua news agency reported.
Widespread contamination prevention efforts have been underway in China and Russia since an explosion on November 13 at a PetroChina chemical factory in the northeast Chinese province of Jilin.
The accident led to the spillage of 100 tonnes of the carcinogens benzene and nitrobenzene into the Songhua River, one of China's longest waterways and a source of water for millions.
The Songhua flows into the Heilong river which is connected by waterways to a river on the Russian side.
As of early Saturday, the maximum nitrobenzene density at Jiamusi, a major city on the river, measured 0.173 milligrams per liter, but shortly afterwards fell to 0.162 milligrams per liter, according to the agency.
The density of the toxic slick will continue to fall as it moves downstream and eventually crosses into Russia, Xinhua said.
