Read this before you eat at Chinese restaurants next time. Every year, two to three million tons of swill-cooked dirty oil, soaked with poisonous carcinogens have sneaked back to our dining tables through an underground muck-money network so rampant that it's an open secret in the industry, the China Youth Daily reported Wednesday.

A deadly toxin found in swill-oil is aflatoxin, which is among the most carcinogenic substances ever known and is 100 times more poisonous than the forbidding white arsenic.

The stomach-turning news report quoted a veteran food professor as saying "about one in ten meals" at the country's restaurants is cooked with such dirty oil, a calculation based on China's annual oil consumption of 22.5 million tons.

"You must have eaten the swill oil as well," asserted He Dongping, a professor on oil and toxin with central China's Wuhan Polytechnic University, and also a leading specialist with China's Food and Oil Standardization Administration, who has spent over seven years on an up-hill task -- how to detect and stop the despicable practice.

According to an undercover investigation in Wuhan by nine senior students of professor He, the conspiracy starts at night when swill-fishers hollow out the stinking hogwash from urban sewages, followed by filtrating, heating, subsiding, dividing, and then in the morning comes out the clear-looking "edible" oil for unwitting customers.

Each fisher could fetch up to four barrels at a time, nearly 300 yuan ($44) easy money every night or over 10,000 yuan ($1,465) a month, a lucrative deal too tempting to resist, especially so when the business was in a trouble-free "anarchy" state, said professor He.

The crux of the matter, in He's opinion, has to do with government management rather than detector gadgets, because without lab equipment, the only reliable counter measure for a common customer so far is special test paper, still a far cry from reality, the professor admitted.

"It might take about 10 years before China could get rid of the swill-oil completely," he said. (China Daily)