Do cell phones cause cancer? No one knows for sure. Mobile phones have only been widely used for around 30 years, with the very first ones introduced just over 40 years ago. It's too soon to tell just how harmful cell phones are.
In February 2017, a study published in the Journal of the American Medical Association recorded changes in brain glucose metabolism（葡萄糖代谢）during cell phone use. The study became the first to prove that cell phone use changes brain activity by monitoring 47 healthy volunteers seated and on the phone for 50 minutes. The volunteers' brains were monitored by special scanners to measure glucose metabolism.
Then in May 2017, the World Health Organization's International Agency for Research on Cancer （IARC）added radiation from cell phones to its list of substances that possibly cause cancer in humans. The IARC'S research found that most cell phone use did not lead to more risk of glioma, a dangerous type of brain cancer, or meningioma, a more common, but typically not harmful cancer. However, the study did find enough evidence that using cell phones for long periods of time on the same side of the head could mean an increased risk of glioma.
In a contrasting report released in July 2017, a British Institute of Cancer Research study found little evidence of cancer risk in 10 to 15 years of use. The study showed that there have been no increases in brain tumors（肿瘤）in several countries over the last 30 years since cell phones were introduced or even in the last 20 years since their use became more widespread.
With no long-term research available yet, limiting exposure to cell phone radiation by texting more and talking less is recommended. Stay off the phone when you have a weak signal, as it will need more radiation to contact the tower. Phone use for children should also be limited because their brains absort twice as much cell phone radiation.
