Why the WHO cellphone and brain cancer study is meaningless

Posted: June 2nd, 2011 | Author: | Filed under: Statistics | No Comments »

Not surprisingly, everyone has massively overreacted to the WHO cellphone and cancer report (including my mother). Here is a sampling of my favorite headlines from yesterday:

The report actually said: radiation from cellphones is a class 2B carcinogen. To put this in context, I have listed the full range of classifications and a few items from each:

  • Group 1: The agent is carcinogenic to humans (tobacco)
  • Group 2A: The agent is probably carcinogenic to humans (frying things, indoor combustion aka having a fireplace)
  • Group 2B: The agent is possibly carcinogenic to humans (pickled vegetables, alcoholic beverages)
  • Group 3: The agent is not classifiable as to its carcinogenicity to human (caffeine, Tylenol, hydrogen peroxide)
  • Group 4: The agent is probably not carcinogenic to humans (caprolactam)

Only one of the 900 tested items has ever been classified group 4. To me, the preceding fact and this scale sounds like a bunch of lawyers covering their asses.

After reading the entire report, their conclusion was based on one study, ending in 2004, which found a 40% increase in cancer among heavy (>30 minutes per day). This is only one report of hundreds, each with several age groups, several levels of usage, and many other variables. Think of it this way. If you took 10,000 people, gave them each a quarter, and asked them to flip it 10 times. Would you be that surprised if one flipped 9 or 10 heads. Of course not, you would attribute it to randomness. The WHO or anyone else claiming that cellphone radiation and brain cancer are linked because of one group in one study is like claiming the person who flipped 9 or 10 heads is a skilled magician who could repeat this feat over and over again. Science is repeatable. If only one study finds this link when hundreds have tried, its not very believable.

CNET posted an excellent and lengthy article with the radiation levels of a long list of cell phones. If you are curious (or really bored) here are the list of all things currently classified by the WHO, the full WHO press release, and the conflicts of interest for those on the panel. The “official” results will be posted in the academic journal, The Lancet Oncology.

Finally, I promise that not every one of my posts will be titled “Why X is meaningless”



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