The Taipei City Government said on Monday that it would buy the rice harvested on the Guandu Plain after fears mounted that the crop was tainted by high levels of arsenic in hot spring waters used to irrigate it.

One scientist insisted, however, that the rice posed no threat to public health because the amount of arsenic detected in the rice was extremely low.

Local Chinese-language daily the United Daily News ran a front-page story on Monday reporting that 123 hectares of farmland in the Guandu Plain contained arsenic at levels exceeding 60 parts per million, far higher than the national standard, according to a study conducted by National Taiwan University Professor Chang Tsun-kuo.

The report also said that the arsenic found in the farmland originated from the popular "Hell Valley" hot spring in Taipeis Beitou district.

The report and other follow-up coverage raised concerns over whether arsenic posed a serious danger to either hot-spring enthusiasts or rice consumers.

"The city government will purchase the first harvest of the plains rice crop and teach farmers to grow non-edible crops," said Taipei Mayor Hau Lung-bin （郝龍斌） as he tried to put the minds of local residents and farmers at ease.

Hau noted that the city government found the soil in the Guandu plain to contain a higher concentration of arsenic three years ago and commissioned professor Chang to launch an investigation.

Changs report, made public on Monday, showed that the pollution did not come from human pollution, but originated from minerals found in Hell Valleys riverbed, Hau said.

The mayor added that arsenic could cause great harm to human health if it was inhaled or consumed, but so far reports provided by hot spring business agencies did not find any adverse reactions related to the hot springs.

Chen Hsiung-wen （陳雄文）, director of the Taipei City Government Bureau of Construction, said that of the 60 crop samples collected from the Guandu Plain, only two were discovered to have arsenic levels surpassing the permissible level of 1 part per million －－ both measuring over 1.16 ppm. Chen noted the city government would continue investigating whether the high level of arsenic in the soil is being absorbed by the crops.

Professor Chang stressed that the arsenic level found in the rice grown on the plain was too low to have any effect on public health.

"The arsenic detected in the rice is only 0.2 ppm. Taiwan has not set a standard for the amount of arsenic that can be found in crops. But Germany regulates that the standard range of arsenic in crops should not exceed more than 1 ppm," Chang said.

The professor noted the content of arsenic in the valleys riverbeds or rocks reaches the thousands or tens of thousands ppm, but the arsenic found in the water in the valley was only 0.5 ppm.

Chang dismissed speculation that the presence of the toxin could set off another wave of blackfoot disease, a vascular ailment triggered by contact with arsenic in which blood vessels in the lower limbs are severely damaged. The disease was prevalent in southern Taiwan in the 1960s.

He noted that farmers in the Guandu region have been irrigating their farms with waters from Hell Valley for the past 200 years without any reported cases there.

"According to research, people have a higher chance of contracting blackfoot disease if they drink arsenic-polluted underground water. But I dont think that will happen as people would not drink underground water in Taiwan," Chang said.

He suggested that visitors avoid touching the riverbed or rocks when they enjoy the hot spring in the valley.

"Do not use the valley water to cook eggs, make tea, or cook vegetables, and people with surface wounds should not bathe in the hot springs," he advised.