In a bid to prove China's Pearl River is now clean enough for swimmers to dive in, Chinese officials mobilized 3500 swimmers who plunged into the river to confirm its cleanliness in a mass swim.

Xinhua news agency quotes the local provincial governor confirmed the river was, "no longer thick and smelly." The Pearl River flows through Guangzhou, the capital of China's industrial province of Guangdon.

At the end of the exercise, one swimmer still rubbed sore eyes after emerging from the formerly toxic river. Some toxic material had resisted the government sanitation campaign.

The swimmer whose surname was listed as Fan told the state news agency, "Under the water, I could not see things 0.5 meters in front of me. And my eyes were uncomfortable." The most recent mass swimming exercise at the Pearl River dates as far back as the 1970s. After that swim, the river was seriously polluted by industrial waste.

Liu Youhong, a 65-year old environmental campaigner says, "The water became so smelly that nobody dared swim there and people even covered their noses when walking by." The Pearl, which is China's third longest river, is 2200 Km in length and 700 meters in width. It is one of China's most polluted rivers which authorities have earmarked for clean up.