Luke Skywalker
Super Moderator
{vb:raw ozzmodz_postquote}:
A commuter shows the Didi Chuxing app on her iPhone in Beijing, China, 13 May 2016.(Photo: HOW HWEE YOUNG, EPA)
A study released Friday<span style="color: Red;">*</span>found an increased risk of certain<span style="color: Red;">*</span>cancers in animals exposed to cell phone radiation, a conclusion that<span style="color: Red;">*</span>could reignite concerns over the safety of the widely used devices.
However, some scientists<span style="color: Red;">*</span>expressed serious concerns about the study, noting inconsistencies in its results.<span style="color: Red;">*</span>Even officials at the National Toxicology Program, which<span style="color: Red;">*</span>conducted the research,<span style="color: Red;">*</span>said the report fails to provide the clear answers many seek.
Researchers found small increases in rare cancers in the brains and hearts of male rats exposed to nearly constant, high doses of<span style="color: Red;">*</span>radiation from cell phones, compared to rats that weren't exposed. There was no increase in cancer among exposed female rats,<span style="color: Red;">*</span>according to the<span style="color: Red;">*</span>study, which represents "partial findings" of a larger project that includes experiments in mice.
The rats were exposed to "whole body"<span style="color: Red;">*</span>cell phone<span style="color: Red;">*</span>radiation for a total of nine hours a day for two years. About 2% of exposed rats<span style="color: Red;">*</span>— 11 out of 540<span style="color: Red;">*</span>—<span style="color: Red;">*</span>developed malignant gliomas, a type of brain tumor. About 3.5% of exposed rats — 19 out of 540<span style="color: Red;">*</span>— developed a type of tumor called a schwannoma in the heart. Schwannomas also can develop in the acoustic nerve, which is<span style="color: Red;">*</span>involved with hearing.
None of the rats in the control group, which<span style="color: Red;">*</span>wasn't<span style="color: Red;">*</span>exposed to radiation,<span style="color: Red;">*</span>developed either type of<span style="color: Red;">*</span>tumor. Yet, in a surprising finding, those animals lived shorter lives than the ones exposed to the cell phone radiation.
The low-frequency radiation emitted by cell phones<span style="color: Red;">*</span>has long raised concerns that the devices may cause brain tumors, especially near side of the head<span style="color: Red;">*</span>where people hold their phones.<span style="color: Red;">*</span>The<span style="color: Red;">*</span>International Agency for Research on Cancer,<span style="color: Red;">*</span>part of the World Health Organization, classified<span style="color: Red;">*</span>mobile phone use "as a possible carcinogen" in 2011.
However, the radiation given off by cell phones is fundamentally different than the ionizing kind known to cause cancer.<span style="color: Red;">*</span>Unlike the kind given off by atomic bombs, the non-ionizing<span style="color: Red;">*</span>radiation emitted by phones is too weak to damage DNA. That's led many scientists to dismiss the notion that cell phones could cause cancer.
Some cancer experts predict the new study will change that thinking. The study<span style="color: Red;">*</span>represents a "paradigm shift in our understanding of radiation and cancer risk," Otis Brawley, chief medical officer at the<span style="color: Red;">*</span>American Cancer Society, said<span style="color: Red;">*</span>in a<span style="color: Red;">*</span>statement.
"The findings are unexpected; we wouldn’t reasonably expect non-ionizing radiation to cause these tumors," said Brawley,<span style="color: Red;">*</span>who wasn't involved in the research. "This is a striking example of why serious study is so important in evaluating cancer risk."
The CTIA, which represents the cell phone industry, said the study's findings conflict with other medical evidence. In a statement, the group noted there's been no increase in brain cancer since the 1980s, when people first began using<span style="color: Red;">*</span>cell phones. A 2011 Danish study, which included<span style="color: Red;">*</span>more than 358,000 adults born after 1925,<span style="color: Red;">*</span>also found no link between cell phone use and brain tumors.
Given these trends, the risk of cancer related to a cell phone is relatively low, Brawley said.
"If cell phones cause tumors, they don't cause a lot of them," Brawley said.<span style="color: Red;">*</span>"If the risk exists, the is really, really small. It's more like the cancer risk from eating red meat than from smoking cigarettes."
Authors of the study acknowledged its limitations.
Cancer rates among rats in the control group were far below what's typical in lab animals,<span style="color: Red;">*</span>which could skew the results, authors noted in the study. The unexposed rats also may not have lived long enough to develop brain tumors, they noted.
The unusually low brain tumor<span style="color: Red;">*</span>rates among unexposed rats could also create the<span style="color: Red;">*</span>illusion of a difference in cancer risk that doesn't actually exist.
Some scientists<span style="color: Red;">*</span>said the increase in cancer could have been a fluke.
In written comments published with the study,<span style="color: Red;">*</span>Michael<span style="color: Red;">*</span>Lauer, a<span style="color: Red;">*</span>researcher with the National Institutes of Health's office of extramural research, said the study was too small to produce reliable results. Lauer notes that only a handful of rats developed cancer in each experiment. Researchers who study cancer risk usually require studies showing an increase of hundreds or even thousands of tumors before making conclusions about cause and effect, he said.
John Bucher, associate director of the National Toxicology Program, said it's not clear what, if anything,<span style="color: Red;">*</span>the animal study reveals about cell phone use in people.
"It may have relevance," Bucher said. "It may have no relevance."
Brawley noted rats in the study were exposed to extremely high signal strengths that were<span style="color: Red;">*</span>"near but below levels that would cause animal tissue to heat up."
"Additional research will be needed to translate effects at these high doses to what might be expected at the much lower doses received by typical or even high-end cell phone users," Brawley said. "Cell phone technology continues to evolve, and with each new generation, transmission strengths have declined and with it radio frequency exposures.”
People who are concerned about the<span style="color: Red;">*</span>cancer risk can take steps to reduce their exposure to radiation by using earbuds or blue-tooth devices, which put more distance between the phones and the brain,<span style="color: Red;">*</span>Brawley said. People can also opt to limit their kids' use of cell phones, given that children's brain are still developing.
"Kids don't talk on cell phones anymore," Brawley said. "They text." If the link between cell phone radiation and cancer is real, "that may be a good thing."
Powered By WizardRSS.com | Full Text RSS Feed