Authorities in three cities say metro machines do not pose radiation risk

BEIJING - Environment authorities in Shenzhen, Guangdong province, have insisted that X-ray machines used on its subway network are harmless, despite the fact they have not received safety permits required by law.

The 286 machines fitted at stations throughout the network are yet to obtain radiation licenses or undergo environmental assessments, but they pose no danger, Shenzhen Habitat Environment Committee said, according to a Xinhua News Agency report.

The announcement came in response to a report by Southern Metropolis News that the radiation emitted by X-rays at Shangmeilin and Jingtian stations had tested at more than 1 microsievert an hour, which means by law they need to pass an impact assessment.

The security devices, which are also commonly seen in Shanghai and Beijing, were installed in Shenzhen in June ahead of the city's hosting of the University Games.

"We were given lectures and courses about working security before taking the job," said a security guard at Convention Center Station, who refused to give his name. "Our shifts change every 30 or 40 minutes to reduce the harm of radiation."

Another worker for Shenzhen Metro, Chen Simin, added: "There's no need to worry about radiation as long as passengers don't put their hands into the machines."

On Tuesday, subway operators in the metropolis eased security procedures from inspecting all passengers to doing sample checks.

Some X-ray machines used in Shanghai Metro stations were also found not to have the necessary licenses on Oct 10. Like in Shenzhen, the city's environmental bureau moved quickly to quell fears over safety, with officials pledging to assess all machines by the end of this month.

All X-ray security machines at airports and metro stations in Beijing have gone through the required checks and have obtained radiation safety licenses, according to the capital's environmental protection bureau.

Du Shaozhong, the bureau's deputy director, said that if a machine meets safety standards, the radiation emitted is very small and the danger posed to passengers is "very low".

"To put the issue in perspective, the radiation received from taking a chest X-ray is the equivalent of standing in one of these subway security machines for 50 hours," he said. "There's no need for people to worry."

However, Xia Yihua, a researcher at the China Institute of Atomic Energy, said carrying out assessments before putting X-ray units into use is vital, as ones that do not meet the standards pose hidden dangers to people and the environment.