Claims that cellular and Wi-Fi networks are a public health risk were dealt a blow earlier this month, as the results of a 30-year study headed by the University of Sydney showed that in Australia, there has been no rise in incidences of brain cancer since cell phone use became more widespread during the ’80s.
Simon Chapman, Emeritus Professor in Public Health at the University of Sydney and one of the lead researchers behind the study, discussed the results in a post on Quartz — good thing, because the original article was published in The International Journal of Cancer Epidemiology, Detection and Prevention and is behind a $31.50 paywall. The study is based on relatively simple, data-driven research. Researchers compared incidences of brain cancer since 1982 with the rate of rise in cell phone use since the ’80s, and found that incidences were mostly stable over that time. If cell phone use were a potential causal factor in brain cancer, a dramatic or at the very least slight increase would have been expected.
Because incidences of cancer must be reported in Australia by law, the study isn’t hurting for numbers — the study looked at 19,858 men and 14,222 women diagnosed with brain cancer between 1982 and 2012, coming from all age groups. Despite cell phone usage growing from 9 percent of the population in 1993 to 90 percent today, the study indicates that rates of brain cancer stayed stable for women and raised slightly for men. However, much of the increase came from the over 70 group — researchers suspect this rise was due an overall improvement in diagnosis of brain cancer in older patients since 1982.
The study is significant because it’s one of the first major, large-scale studies to dispute the claim that an increase in brain cancer has not been seen because of lag time. Chapman discusses a prominent advocate for the risk of cell phone usage, Devra Davis, who is among many claiming that radiation from cell phones is a long-term carcinogen that will trigger an epidemic in the years to come.
The study and the analysis of the results raise two important points. One is that although cell phone use was relatively uncommon until the late ’90s and early ’00s, at least some small increase in the rate of brain cancer would have been expected by now among early adopters, assuming the lag time hypothesis is true. The second, which Chapman discusses more at length, is that studies done on other types of cancer suggest that when actual new carcinogens are introduced to a population, rates of cancer grow gradually over decades, rather than hitting all at once as an epidemic. Studies looking at the effects of smoking and atomic bomb radiation found that rates of cancer increased gradually over decades, peaking 30 to 40 years later. With no rise at all seen within the first 30 years since the introduction of cell phones, a future rise looks historically unlikely.
As with any correlative study, causation or the lack thereof hasn’t been established. What this study does do (along with many others) is establish that there’s simply not much reason to think that cell phone is a causal factor of brain cancer. Similar long-term studies are no doubt in the works, so we’ll need to wait on the results of those to have a clearer picture, but at this juncture, claims that cell phone use causes brain cancer seem to be the stuff of junk science.