:: Farhana Choudhury ::
According to an in-depth study conducted by the World Health Organization, The International Agency for Research on Cancer, attended by a working group of 31 scientists from 14 countries reviewed dozens of published studies, put mobile phones in the same possible cancer-causing category as the pesticide DDT, petrol, engine exhaust and coffee. Though they also suggested that much more research is needed. “The conclusion means that there could be some risk, and, therefore, we need to keep a close watch for a link between cell phones and cancer risk,” said Jonathan Samet, a physician and chairman at the University of Southern California, who chaired the panel. Critics of the study, including mobile phone companies, maintain that there is no conclusive evidence that this causes cancer.According to the Centers for Disease Control and Prevention in the US, RF (radio frequency) radiation should not be confused with ionising radiation, such as X-rays or gamma rays. “RF fields have lower energy and therefore cannot cause ionisation (potentially resulting in chemical changes) in the body,” the CDC stated in a 2005 report. “Although some studies have raised concerns, the scientific research, when taken together, does not indicate a significant association between cell phone use and health effects,” the report states.Ed Yong, Head of Health Information at Cancer Research UK, said: “The WHO’s verdict means that there is some evidence linking mobile phones to cancer but it is too weak to draw strong conclusions from.“The vast majority of existing studies have not found a link between phones and cancer, and if such a link exists, it is unlikely to be a large one.“The risk of brain cancer is similar in people who use mobile phones compared to those who don’t, and rates of this cancer have not gone up in recent years despite a dramatic rise in phone use during the 1980s.“However, not enough is known to totally rule out a risk, and there has been very little research on the long-term effects of using phones.”The UK Government advises a precautionary stance. It suggests that if adults want to use a mobile phone, they can choose to minimise their exposure by keeping calls short. It also advises discouraging children under the age of 16 from making non-essential calls as well as also keeping their calls short. IARC announced that mobile phone signals are now classified as ‘possibly carcinogenic’ due to study results suggesting a link to some types of brain cancers.The IARC classifies different substances and exposures according to whether they are likely to cause cancer. The IARC had classified mobile phones as belonging to Group 2B on their scale, which means there is a possibility they cause cancer in humans. Within the IARC scale, there are five categories of risk: • Group 1: There’s extremely strong evidence that an agent causes cancer. Smoking and asbestos are in this category. • Group 2a: An agent is ‘probably carcinogenic to humans’. The evidence in animal studies is ‘sufficient’ but ‘limited’ in humans. • Group 2b: Mobile phones fall into this classification group. An agent is ‘possibly carcinogenic to humans’. There is limited evidence in humans that it causes cancer and the evidence from animal studies is ‘less than sufficient’. This is the new classification for mobile phones. Cancer Research UK consider Group 2B to mean that, ‘there is some evidence for a risk but it’s not that convincing’. • Group 3: An agent is ‘not classifiable as to its carcinogencity to humans’. This means that the evidence is inadequate and limited in humans and animals. • Group 4: An agent is probably not carcinogenic to humans.Scientists are confident that tobacco, alcohol or asbestos can cause cancer because they can explain how these things affect the way our cells work. These explanations are called “biological mechanisms” – they play a vital role in establishing that something causes cancer.So far no one has been able to provide a good biological mechanism for the link between mobile phones and cancer. The “how” question is an open one.