CNET科技资讯网5月18日国际报道 瑞典科学家星期二表示，手机可能对农村地区居住者的健康造成更高的威胁，原因是在这些地区，手机会发射出更密集的信号。

在偏远地区，基站之间的距离更加的遥远，因此电话需要更强的信号。

瑞典Orebro大学医院的教授Lennart Hardell说：“我们发现，居住在农村地区的居民患脑瘤的危险要比城市居民高。”

他说：“信号越强，危险性就越高。”

目前，全球手机的使用正在快速增长，但还没有充分的证据可以证明，手机技术导致了头痛，脑瘤等健康问题。

一些研究人员已经暗示，无线电活动区域可能会干扰生物系统。

健康方面的官员已经敦促公众限制使用手机，或者使用手机免提装置。

Hardell与他的同事研究了1429名恶性与良性脑瘤患者，1470名居住在瑞典中心地区的健康人员，他们表示，手机对健康造成的危险证据还不够充分，除非有人使用手机达10年以上。

他们的研究公布在“职业与环境医学”杂志上。

科学家发现，农村地区，使用手机超过3年以上的居民患脑瘤的机率比城市居民大3倍。

如果使用手机的时间超过了5年，农村地区居民患脑瘤的机率比城市居民高4倍。

研究人员对被访者提出了使用手机频率及其时间长短的问题。他们还询问了被访者是居住在农村还是城市。

Hardell说：“我们尚不能断定在农村地区是否还有其它未知的致病因素。”

他还表示，他们的研究调查的规模相当的小，结论需要被其它人重复。 （编辑：孙莹）

Study: Cell phone risk higher in countryside

Mobile phones could pose a higher health risk to rural dwellers because they emit more intense signals in the countryside, Swedish scientists said Tuesday.

Base stations tend to be further apart in more remote areas, so the phones compensate with stronger signals.

"We found that the risk of brain tumor was higher for people living in rural areas than in towns," said Professor Lennart Hardell, of University Hospital in Orebro, Sweden.

"The stronger the signal, the higher the risk," he told Reuters.

Use of cell phones has increased rapidly worldwide, but there has been no hard evidence that the technology causes health problems ranging from headaches to brain tumors.

Some researchers have suggested that radio frequency fields could interfere with biological systems.

Health officials have urged the public to limit mobile phone use or to use hands-free devices.

Hardell and his colleagues, who studied 1,429 people with malignant and benign brain tumors and 1,470 healthy controls living in the center of Sweden, said the health risks may not be evident until someone has used a mobile for 10 years or more.

Their research is published in the journal Occupational and Environmental Medicine.

The scientists found that rural dwellers who had been using a mobile phone for more than three years were three times more likely to be diagnosed with a brain tumor than city dwellers.

The risk quadrupled after more than five years of use.

The researchers questioned both groups about how often they used their mobile phones and for how long. They also looked at whether they lived in the countryside or in towns.

Their findings were adjusted for other environmental factors that might increase the risk of brain tumors.

"We still cannot exclude that there might be other undetected risks in the countryside, but we have tried to adjust the results, as far as we know," Hardell said.

He added the study was quite small and that the findings need to be duplicated.