To monitor whether there is radiation from Japan, Zheng Wentong has stayed for a week in Laoheishan Town, a remote town in northeast China's Heilongjiang Province near the China-Russia border.

The town, located in Dongning County, is the nearest spot in the province to quake-hit Japan. After the nuclear leak at the Daiichi nuclear plant in Fukushima, Zheng reported the radiation status every three hours to the provincial capital Harbin, based upon the data received from a high-pressure ionization chamber placed outdoors.

"By far, no abnormality has been detected," said Zheng, who is among hundreds of technical workers engaged in 24-hour radiation monitoring in coastal areas of eastern China and provincial capitals.

By Tuesday, eleven days after the catastrophe in Japan, China' s environmental protection ministry had released radiation monitoring information at least 15 times to demonstrate that there is no immediate threat from radioactive leaks.

The intensive information was disclosed after radiation concerns caused fears and public panic. People flooded into groceries, stores and supermarkets to buy salt, assuming that the iodine contained in the salt would help shield them from radioactivity.

The situation eased after the government ordered the securing of salt supplies and as experts confirmed that salt was almost useless to counter radiation.

"My friends told me not to eat seafood or hang out at the beach anymore," said Zhang Yan, a worker at a state-owned company in the coast city of Qingdao in Shandong Province.

Agricultural and sideline products, such as rice and edible oil, was in high demand in some regions. Rumors like "radiation-contained rain" are also spreading through the Internet.

In fact, according to the State Oceanic Administration, the samples from the Yellow Sea coast show no abnormal radiation so far.

Xia Yihua, a researcher with the China Institute of Atomic Energy, said that the public had little access to nuclear knowledge and people are eager to acquire authentic information through authoritative channels.

"The government has attached great importance to nuclear information disclosure, and we release information only after discreet confirmation," Xia said.

Environmental protection authorities required monitoring stations to keep a closer watch on radiation data and report every three hours, instead of twice a day.

On Monday, the Beijing Environment Protection Bureau released environmental protection data on the city from March 12 to 20 and announced that it would continue to disclose the data in the future.

"With the information disclosed, I do not feel so scared. Japan is far from us, after all." said Zhang Yan.

Chai Guohan, a researcher with the Nuclear and Radiation Safety Center operated by the Ministry of Environmental Protection, said that the preciseness and openness of nuclear information was helpful to dispel public panic.

"Central and local environmental protection departments release authoritative information every day, and people should trust it, instead of rumors from other sources," Chai said.