A Gilroy company's recall of Chinese fresh ginger contaminated with a toxic pesticide is the latest scare involving imported ginger and other food products from China.

No illnesses were reported as of Monday, a day after California officials first issued a public warning to advise consumers against eating fresh Chinese ginger.

State and federal health officials are now working to determine how the ginger got into this country and how widely it has been sold. It's not the first time that contaminated Chinese ginger has been a problem.

U.S. port inspectors in Seattle have turned away shipments of Chinese ginger that contained pesticides in recent months, according to news reports. And Japanese authorities acknowledged this month that they mistakenly allowed

25 tons of Chinese ginger laced with pesticide into their country.

This time, California officials said they found potentially harmful levels of the pesticide aldicarb sulfoxide in a batch of fresh ginger from China that was distributed earlier this month by the Christopher Ranch food company of Gilroy. It was shipped to retailers and wholesalers in California, Michigan, Oregon, Louisiana and Washington.

The contamination was discovered in samples gathered randomly from an Albertson's grocery store in Roseville, near Sacramento. The samples were collected by the state Department of Pesticide Regulation, which routinely tests produce for pesticide residue.

Since some of the ginger may have been sold before the retailers were notified of the recall, officials urged anyone who bought ginger from Albertson's or Save Mart stores in Northern California in recent weeks to discard it or return it to the store.

While the ginger was shipped in boxes labeled to show it came from China, the ginger may have been sold in bins — without packaging or labels — in some stores.

"We're very disturbed by what happened," said Christopher Ranch owner Bill Christopher. State officials contacted Christopher Friday, and he said he worked through the weekend to recall about 18,900 pounds of ginger, which he shipped to more than a dozen retail and wholesale clients between July 10 and 26.

China is a major supplier of ginger on the world market. Last year, the United States imported more than 32,000 tons of ginger, nearly half of it from China.

"We grow our own ginger in Hawaii, but it's only available six months out of the year," Christopher said. From May through October, he added, the company sells ginger imported from China.

It wasn't clear how the contaminated batch got into the United States. Christopher said he relied on his importer, Modern Trading Inc., to ensure that the ginger was safe. An employee at Modern Trading, based in Los Angeles County, said she assumed that Chinese authorities had tested it before it was shipped overseas. The importer bought the ginger from Juxian Modern Organic Ginger Co. of China.

The U.S. Food and Drug Administration inspects less than 1 percent of the food imported into this country. While FDA officials could not be reached for comment Monday, they have previously said the agency tries to make the most of limited resources by focusing on high-risk items and products from countries with a history of problems.

Aldicarb sulfoxide causes nausea, headache and blurred vision when ingested in small amounts. The symptoms usually disappear in five or six hours, health officials said. But in larger amounts, the chemical can cause dizziness, sweating, vomiting, diarrhea, muscle stiffness, breathing difficulty — and even death.

The pesticide is highly regulated and is not approved for use on ginger, state officials said.

Tests showed the ginger had 57 parts per million of aldicarb sulfoxide, which a state spokesman said was relatively low but still potentially harmful.

"We would not expect anyone to become seriously ill," said spokesman Glenn Brank of the pesticide department. "But there is always a potential."

Christopher, whose company also distributes imported garlic from China, said he's never had a problem with Chinese ginger or with other products he imports from Modern Trading. 

At the offices of Modern Trading, a woman who declined to give her name said the owner is currently in China. The company, she said, is cooperating with health officials. She said the ginger entered the United States with inspection certificates from the Chinese government and was cleared by U.S. authorities. Officials could not be reached to confirm this Monday.

Recent reports of tainted pet food, toothpaste and other Chinese products have raised concerns about that country's safety standards, while U.S. officials have also come under criticism for not doing more to turn back unsafe imports. Christopher said the government needs to screen Chinese imports more carefully.

"That's the thing about products that come out of China," he said. "You don't really know what they're using, and they don't check at the port."

Contact Brandon Bailey at bbailey@mercurynews.com or (408) 920-5022.