Beijing (AsiaNews/Agencies) - At least since June, the harmful nature of the powdered milk from the company Sanlu had been denounced to the competent general administration for the supervision of quality, inspection, and quarantines. In July, a local TV station in Hunan talked about it, alarmed over the elevated number of children hospitalized with kidney stones. But everything was silenced to avoid scandals ahead of the Olympics, and the media were prohibited from even speaking about it.

Already 78 people have been questioned about the presence of melamine (or tripolicianamide, a substance that can produce kidney stones and is widely used in the production of plastics and fertilizers) in thousands of tons of powdered milk from the company Sanlu, believed to have caused the death of one child and kidney stones in dozens of others.

According to Xinhua, Sanlu, a leader in the dairy sector, had received complaints beginning in March, when many parents reported "red" urine and kidney stones in their children. The contamination was verified no later than August, but was denied until just two days ago. Now the company is defending itself by accusing the producers of adding the substance to the milk, together with water, in order to increase their profits: the melamine molecule is similar to protein, and can make food appear more nutritious than it is if only partial testing is carried out.

But experts and public opinion are skeptical, and are asking how the powerful Sanlu company did not discover and announce the contamination earlier, how many dishonest producers there must be to contaminate the 2,176 tons of product that the company decided to keep off the market and the 8,210 tons recalled, and why it is that only the suppliers of Sanlu are dishonest, and not those of other companies.

Migrants and poor families have been especially affected, in Gansu and other areas, choosing the product because of its low cost (18 yuan, or 1.8 euros, per package) compared to foreign brands believed to be safer.

"The price of 18 yuan", says nutritionist Mao Deqian of the center for disease control and prevention, " doesn't even cover manufacturing costs".

Yesterday, many parents stood outside the main offices of the company in Shijiazhuang. When the executives refused to meet with them, the parents shouted that they are "child murderers". In two days, the official web portal Sina.com has received more than 44,000 comments, most of them calling for a careful investigation and severe punishments. Everyone is asking whether the other products from Sanlu and the other brands of cheap powdered milk are safe. Many say that Beijing must demonstrate that it truly wants to stop such incidents and protect the population, instead of only guaranteeing food safety for foreign VIP's at the Olympic village.

Repercussions on the international market are expected: melamine was found in 2007 in exported animal feed that killed dozens of dogs and cats in the United States, and the fear is that it is frequently used as a food additive, without being identified by inadequate safety controls. It will be one of the topics at the meeting on product safety scheduled for next week between China, the United States, and the European Union.