China's standards for pesticide residue on tea products are reasonable and unlikely to change in the near future, a senior expert has said.

The remarks by Wang Jianhua, an expert on pesticide residue for the Entry-Exit Inspection and Quarantine Bureau of Shandong province, came after the government conceded the long-term use of chemicals on other crops has resulted in widespread contamination of soil and water supplies.

Greenpeace released a report in April saying Chinese products available for the domestic market fall far short of the standard required in the European Union.

However, Wang dismissed public concern resulting from the report and insisted the products tested are safe.

"China's standards on pesticide residue are reasonable, as the standards fully take into consideration the potential risks to public health," he said on Tuesday.

"What authorities should be paying serious attention to is the usage of highly toxic pesticides in agricultural production, which is ongoing. Some areas of production have no standards on pesticide residues at all."

Wang declined to name specific pesticides.

The Greenpeace report, released on April 23, said scientists had discovered residue from 17 pesticides, including methomyl, a pesticide banned in China, in some Lipton teas.

Seven of the pesticides are also prohibited in the EU, including endosulfan and bifenthrin, which according to EU health officials might jeopardize fetal health and men's fertility, the NGO report said.

The test result was based on samples of Lipton's black, green, jasmine and tieguanyin teas purchased randomly in Beijing in March.

Testing was conducted at a nationally qualified laboratory, although Greenpeace declined to disclose its name to "ensure its independence".

Another report from the environmental NGO in early April showed that at least three pesticides banned by the Ministry of Agriculture were detected in products from nine major tea companies, including Zhang Yiyuan and Wu Yutai.

Officials from the Ministry of Agriculture and the Ministry of Health said at a news conference on Saturday that residues of illegal pesticides found on the tea may be caused by wind blowing over from other crops.

Long-term use of the pesticide on other crops may leave residue in the water and soil, said Dong Hongyan, an official with the Ministry of Agriculture.

"For instance, methomyl, which is banned on tea plants, can still be used on other agricultural products in China. It is inevitable that pesticides will travel through wind or the flow of air when the tea is planted next to some other crops," he said.

Also, he said, not all pesticides used in tea production in China have been registered in EU countries as they are not major tea producing regions.

"Many countries with vast amounts of imported agricultural products always adopt stricter standards on pesticide residues," Wang said. "But sometimes setting such standards has nothing to do with the products' safety. It is a measure to guarantee their economic interests in world trade."

Last year, China banned 10 of its 22 highly toxic pesticides in response to growing concern about the safety of agricultural products because of the misuse of such chemicals.

Fifty-thousand tons of the 22 highly toxic types of pesticides are produced each year, accounting for 2.5 percent of the country's annual total pesticide production, official figures showed.

"Government authorities should set up residue standards for all the highly toxic pesticides and conduct further research on substitutes for the other 12 types and ban them as soon as possible," Wang said.

jinzhu@chinadaily.com.cn