XUZHOU, CHINA — Before Mao Lijun's business exported tainted wheat products that may have killed American pets, his factory sickened people and plants around here for years.
Farmers in this poor rural area about 400 miles northwest of Shanghai had complained to local government officials since 2004 that Mao's factory was spewing noxious fumes that made their eyes tear up and the poplar trees nearby shed their leaves prematurely. Yet no one stopped Mao's company from churning out bags of food powders and belching smoke -- until one day last month when, in the middle of the night, bulldozers arrived and tore down the facility.
It wasn't authorities that finally acted: Mao himself razed the brick factory -- days before the investigators from the U.S. Food and Drug Administration arrived in China on a mission to track down the source of the tainted pet food ingredients.
In the end, Chinese authorities caught up with Mao and arrested him. And Tuesday, after weeks of denials, China acknowledged that Mao's company and another Chinese business had illegally exported wheat and rice products spiked with melamine, a chemical used in making plastics and fertilizers. That chemical is banned in foods in the U.S.
China's watchdog agency said the businesses had added melamine to the food ingredients "in a bid to meet the contractual demand for the amount of protein in the products." Melamine can make animal feed appear to have more protein than it actually does.
Besides turning up in pet food, melamine has been found in feed for thousands of hogs and millions of chickens in the U.S. The FDA said Tuesday that melamine-contaminated foods also were fed to fish raised for human consumption. But in each case, U.S. officials said there was little risk to human health.
The FDA also said that although the tainted Chinese products were labeled as wheat gluten and rice protein, they were actually ordinary wheat flour -- with melamine and related nitrogen-rich compounds.
Melamine producers in China have said that melamine scrap, a cheaper form of the chemical, has been widely sold to entrepreneurs who use it to fool farmers into thinking that they are getting higher-nutrient animal feeds. Among the apparent buyers of melamine scrap were Mao, head of Xuzhou Anying Biologic Technology Development Co., and Binzhou Futian Biology Technology Co. in Shandong province.
Liu Zhaoyi, 64, a farmer who lives next to Mao's now-demolished factory, recalled seeing globs of white and yellowish scrap, which may have included melamine, piled in the yard behind the plant.
One season after rains, Liu said, water with residue from the compound flowed into his family's cornfields and killed the crops.
"He gave me only 100 yuan when my corn was all dead," Liu said of Mao. That is the equivalent of about $13 today.
Few people in town, which has a large food manufacturing industry, seemed to know what Mao's factory made.
An Environment Protection Bureau official in Pei county, which is a part of Xuzhou, said one of his colleagues had visited Mao's facility in recent years when it was processing yeast and wheat. The inspection did not turn up any serious violations, and neighbors were told to complain to a court or another agency.
In recent days, Mao's company removed wheat gluten from the product offerings on its website. It also deleted something called ESB protein powder.
Xuzhou Anying had advertised the powder as its "latest researched, developed and produced" item and touted it as "a new way to solve the problem of shortage of protein resource." Several people with experience in China's food industry say such powders are invariably made with melamine.
Melamine itself isn't considered particularly toxic, but researchers believe that another compound, cyanuric acid, may also have been added to the pet food ingredients by Chinese firms or formed as a byproduct. Combined with melamine, it can cause a chemical reaction -- forming crystals and blocking kidney function in some animals.
Cai Kesen, president of No. 1 Flour Factory of Pei county, said unadulterated wheat gluten from China certainly would not have caused a scandal. The quality of the region's wheat last year was the best in a decade, he said.
Cai vaguely recalled meeting Mao once. His company was small, he said, and it was common for such businesses to add words like "biologic" and "technology" to their names to get government subsidies intended for advanced enterprises.
Xuzhou Anying's website posted certificates claiming, among other things, that it had won top quality grades from various organizations, none of which could be verified.
China's General Administration of Quality Supervision, Inspection and Quarantine said Tuesday that Xuzhou Anying and Binzhou Futian had evaded quality checks by labeling their products as exports not subject to inspection.
Farmer Liu said it was a shame that officials failed to heed earlier complaints. "If they had done more, this company won't have such a big problem."
Lee reported from Xuzhou and Goldman from Los Angeles.