Food safety authorities in Qingdao, Shandong Province, have temporarily halted the sale of Chinese chives after seizing almost 2 tons of pesticide-tainted chives last week.

Nine residents have reportedly been poisoned after eating toxic chives this month. They have joined hands to ask for compensation from a local food vendor.

The patients complained of headache, nausea and diarrhea after consuming dishes that contained chives at a local fast food restaurant, Qilu Evening News reported.

All of them were poisoned by organic phosphorus, a highly toxic pesticide, officials from the Qingdao Health Supervision Bureau said.

"I bought a box of fried eggs with chives for 3 yuan (40 US cents) last Wednesday. My husband had two bites and my child didn't eat any. I ate all of the rest," one of the patients, surnamed Yang, was quoted as saying.

She said the poisoning symptoms appeared 15 minutes after she had the dish.

"I was not thinking about the chives at all. Instead, I wondered if I was having some heart problems. I called my husband immediately," she said.

The other patients consumed the dishes at the same restaurant.

After recovering, the nine have filed a case with the local bureau of industry and commerce, demanding compensation.

Follow up inquiries revealed the tainted chives might not be just limited to one restaurant.

Random checkups on over 2,000 batches of chives, conducted from April 2 to April 9 in three vegetable wholesale markets in Qingdao, found 1,930 kg of chives contained excessive pesticide residue.

The tainted chives have been destroyed, the industry and commerce bureau told reporters at a press conference late on Friday.

A pesticide residue rate as high as 64 percent was tested on the vegetables, and investigations traced the chives back to the city of Gaomi in Shandong Province, said Yue Hao, an official with the local industrial and commerce bureau.

A visit to the three vegetable wholesale markets over the weekend found dealers had stopped selling chives, local media reported on Sunday.

Several randomly interviewed passers-by said they would not eat any chives for a while. Dealers said they had stopped selling the vegetable last Friday, citing a prohibition from the market authorities as the reason, the report said.

However, a manager surnamed Zhang from one of the markets said there was no such prohibition, but the dealers were not selling chives as a safety measure.

"The current supervision on chives is quite strict. A problematic sample will lead to major problems."

In April 2009, media in northeast China's Liaoning Province reported that a 6-year-old girl in the provincial capital of Shenyang died after eating chives. Doctors said she was poisoned by organic phosphorus.

In April 2004, tons of tainted chives from Xianghe of Hebei province were found in the Beijing market. The chives contained high rates of phorate residue, a kind of organic phosphorus pesticide.

In May 2002, the Health Times, a publication under the People's Daily, explained the cause for using highly poisonous pesticides on chives in one of its reports.

"The most serious pest problem for the chive plant is maggots, which live underground and nip on the plant's roots. Normally-splashed pesticides could not solve the problem, while the organic phosphorus pesticides cannot only kill the pests, but also promote the growth of the roots," said Wang Kaiyun, a professor in pesticides research at Shandong Agriculture University.

(China Daily April 12, 2010)