WASHINGTON (Reuters)- Researchers reported on Tuesday that studies on whether cell phones can cause cancer, especially brain tumors, vary widely in quality and that those at least risk may have some bias. So far, it\'s hard to prove any connection, and while the best research does suggest some kind of association between cell phone use and cancer, the team led by Dr. Seung- The rights to the National Cancer Center in South Korea were clearly discovered. Myung and colleagues from Seoul pear blossom Women\'s University and Seoul National University Hospital and the University of California, Berkeley studied 23 published studies of more than 37,000 peopleanalysis. They found that the results of the study often depend on who conducted the study and how well they were in control of bias and other errors. \"We found that there was a big difference in the association between cell phone use and tumor risk between the research team, which was confused with the quality of the methods studied, they wrote in The Journal of Clinical Oncology. The use of mobile and cordless phones has surged over the past 10 years, with an estimated 4. According to US data, there are 6 billion users worldwide. N. International Union of Telecom The study failed to establish any clear link between the use of these devices and several cancers. The latest study is supported to some extent by the United States. S. The Centers for Disease Control and Prevention examined cases involving brain tumors and other diseases, including facial nerves, saliva and testicles, and non- He sportshero jin shi lin ba liu The study found no significant association between tumor risk and overall use of mobile phones, including mobile phones and cordless phones. Myung\'s team said eight studies used a \"high quality\" approach to blind participants and found that people using their phones were at risk of cancer compared to people who never or rarely used them. People who use their phones for 10 years or more have also found an increased risk of benign rather than malignant tumors. The Myung team said the \"high quality\" study was funded by the Swedish working Environment Fund, the olibro Cancer Fund and the Cancer Fund of the olibro University Hospital. In contrast, studies using the \"low quality\" approach to eliminating bias found that mobile users were at a lower risk of developing tumors than people who rarely use these devices. Myung\'s team believes that due to the quality of the method, these results may be destroyed by random errors and deviations. Funding for some lower countries Quality research includes two industry groups, the Mobile Manufacturers Forum and the global association for mobile communication systems, the researchers said. In general, the studies examined were not extensive enough to clarify whether the use of a cell phone would lead to a tumor. Myung\'s team says a larger study of a type called queue study is needed to answer this question. In this case, the studies tracked a group of people with common features, in which case they used mobile phones and compared them with other groups over time. The only Cohort Study published so far showed no association between cell phone use and tumors. But the study, conducted in Denmark, relied on a telephone subscription and did not assess the actual exposure to the phone.