Kitchens of the training centers for top athletes seem to be the most important places under strict lockdown. The control is tight to keep raw food items contaminated with clenbuterol away.

Chinese athletes' concern about meat on the market points to a hole in the country's pig and cow farming and supply.

On its website, the General Administration of Sport has banned pork, beef and mutton on its athletes' menus when they eat out. It cautioned that the country's anti-doping testing lab had done experiments showing that eating pork meat or pork liver containing clenbuterol, or lean meat powder, as it is often called, can trigger a positive result.

Responding to the latest reports on some Chinese athletes who are qualified for the London Olympics and are avoiding meat, the agency said that it is very strict with its athletes' meals, nutritional supplements and drugs. The pre-emptive measures are taken to help Chinese athletes shun the doping issues caused by the contaminated foods.

The World Anti-Doping Agency, the International Olympic Committee and other international sporting organizations ban clenbuterol due to its muscle-building properties. Several athletes of this country and other parts of the world had tested positive for clenbuterol and laid the blame with meat they had consumed.

On April 19, China National Cereals, Oils and Foodstuffs Corporation signed an agreement with the Chinese Olympic Committee, promising to supply our athletes with safe meat at the London Olympics.

Some athletic teams have built their own farms to raise pigs and chickens to shun the risks of accidental clenbuterol doping

On February 24, Liu Qingya, a pig farmer in Jiangsu province, came to the local athletes' rescue. He donated 3 tons of pork free from "lean meat powder" to the provincial sport department.

The athletes' distrust in the meat humiliates the officials who are responsible for our food safety.

It is an open secret that many hog breeders feed one or two pigs with normal fodder for their own meals. Driven by high profits, farmers feed small amounts of the drug to pigs in the hope that it will greatly improve their muscle and shorten the growing period, despite a governmental ban. If farmers stop using the chemical several weeks before the pigs are slaughtered, it is hard to detect.

Clenbuterol residues can affect lung and heart function in people who have eaten liver or meat of animals given the drug. It is potentially dangerous and can have nasty side effects for humans. These can include headaches, trembling, nausea, heart palpitations and other poisoning symptoms.

The fact that the athletes abstain collectively from the meat sold at the public markets should awaken the nation not just to the dangers in the food supply, but to the central role the government has to play in keeping it safe.

As early as 2007, the Ministry of Agriculture claimed that almost 100 percent of China's slaughterhouses, wholesale markets and farm produce markets comply with the ban on the use of clenbuterol.

But during a major crackdown by the authorities in March 2011 alone, nearly 1,000 people were arrested, and large amounts of tainted meat and stores of the drug were confiscated.

Our food safety system must improve. Many sectors of the food industry have presented a poor record of their food.

The government needs to make bold change in how this country addresses how our food is grown, raised and processed, tracked, sold and cooked for Chinese consumers.

Like all warnings that have come in the past, it would be easy to bury our collective heads in the sand and once again accept the standard approach throw a band-aid on the system. The food safety system often deals with individual foods, not food systems. The government needs to put real teeth into regulation, inspection and enforcement.

The author is a senior writer with China Daily. E-mail: caihong@chinadaily.com.cn