Harmless levels of radioactive material from a crippled Japanese nuclear power plant can still be found in most regions of China on Saturday but protective measures are not necessary,according to China's National Nuclear Emergency Coordination Committee.

As of 9:15 a.m. Saturday Beijing Time, no changes have been observed on the readings at the on-site radiation monitoring posts at the quake-damaged Fukushima Daiichi Nuclear Power Plant in Japan and levels of radiation in its surrounding areas were down, says a daily statement issued by the committee, quoting a report of the International Atomic Energy Agency.

Extremely low levels of radioactive isotope iodine-131 were detected in the air over the East China Sea and some areas of all provincial-level regions except Yunnan.

Trace levels of radioactive isotope cesium-137 and -134 were detected in the air of 25 of the Chinese mainland's 31 provincial-level regions. it says.

Cesium-137 and -134 were found in Beijing, Shanghai, Tianjin, Hebei, Shanxi, Inner Mongolia, Liaoning, Jilin, Heilongjiang, Jiangsu, Zhejiang, Anhui, Fujian, Jiangxi, Shandong, Henan, Hubei, Hunan, Hainan, Sichuan, Shannxi, Ningxia, Qinghai, Gansu and Xinjiang.

Minimal amounts of iodine-131 were detected in spinach planted in Beijing, Shandong and Jiangsu. The radioactive isotope was also found on lettuce in Jiangsu and Indian lettuce in Guangdong.

No obvious change has been found on the levels of radioactive material in China and sample survey shows drinking water shows no abnormality, according to the statement.

The current levels of radioactive materials pose no threat to public health or to the environment, it says.

No protective measures need to be taken against contamination from these materials, says the statement.

The committee's conclusion was based on monitoring and analysis results from the Beijing-based Regional Specialized Meteorological Center affiliated with the World Meteorological Organization and the International Atomic Energy Agency, the State Oceanic Administration, the Ministry of Environmental Protection and the Ministry of Health, according to the statement.