A study of people who used cell phones for an average of less than three years found no evidence the devices cause brain cancer.

admin2010-03-26  43

问题     A study of people who used cell phones for an average of less than three years found no evidence the devices cause brain cancer. The research didn’t, however, answer the question of whether longer-term use is dangerous. The study of 891 people did find a slightly increased risk for a rare type of brain cancer, but the researchers said it was not statistically significant. While they acknowledged longer-term studies are needed, the researchers said the overall results should reassure the more than 86 million cell-phone users nationwide. "We feel confident that the results reflect that cell phones don’t seem to cause brain cancer," said epidemiologist Joshua Muscat, a scientist at the American Health Foundation who helped lead the study.
    Publication of Muscat’s research prompted the New England Journal of Medicine to release a study showing similar results. The study, led by National Cancer Institute researchers, looked at 782 brain cancer patients and 799 people without cancer. Maximum cell-phone use was at least an hour per day for five or more years, and no brain-cancer link was found even at that level.
    Unlike regular telephones, handheld cell phones contain an antenna inside the receiver, which puts the user’s brain close to the electromagnetic radio waves the antenna emits. Since cell phones were introduced in the United States in 1984, conflicting data have emerged from safety studies on animals and humans.
     The Food and Drag Administration (FAD) has said there is no evidence that the phones are unsafe, but it has joined with wireless industry in sponsoring research on the devices. Some cell-phone makers have also started disclosing their products’ radiation levels.
    Another study involved phone-use questionnaires given to 469 men and women aged 18 to 80 with brain cancer and a 422-member cancer-free control group. Cell-phones use was slightly more common among the cancer-free participants, though average cell-phone use for both groups was under three hours monthly for less than three years.
    The amount and duration of cell-phone use were not related to an increase brain cancer risk except for a type of neuron-cell tumor called neuroepitheliomatous cancer. Of the 35 patients with this rare tumor, 14 percent used cell-phones.
"antenna" in the third paragraph probably means ______.

选项 A、feeler
B、aerial
C、circuit
D、metal

答案B

解析 语义理解题。由antenna所在句后面从句中的electromagnetic radio waves“电磁波”和 emit“散发;等词可以推出antenna为天线的意思,因为其他三个词都不常与emit构成语义搭配.故本题答案为B。A“感觉者”;C“电路”;D“金属”。
转载请注明原文地址:https://jikaoti.com/ti/RqYMFFFM
0

最新回复(0)