Wednesday, January 16, 2013

Drs. Oz & Gupta Caution About Cell Phones

Dr. Mehmet Oz, in a recent episode of his popular TV program, "The Dr. Oz Show," and his guest, Dr. Sanjay Gupta, a neurosurgeon and chief medical correspondent for CNN, discussed cell phone radiation health effects.  Dr. Gupta issued important precautionary messages about cell phone use.

Both Dr. Oz and Dr. Gupta should be commended for their continued work in reporting about the health risks associated with cell phone radiation and for issuing precautionary warnings to the public.

Dr. Gupta provided some misinformation in this interview which I address in my comments below.


Are Cellphones Dangerous for Your Health?

The Dr. Oz Show, Original air date: Jan 15, 2013

Are cell phones a serious health risk on par with tobacco and asbestos? Dr. Oz and Sanjay Gupta separate fact from fiction on this hotly contested issue. Plus, the medical reason why you should wait to give your child a cell phone.

5 minute video clip:

Episode Summary and My Comments

Gupta: "I think both groups you just mentioned, people who say it's absolutely safe and people who say it's absolutely dangerous, they don't know. And that's the important point here."

My comment:  Very few health scientists or medical professionals argue either that cell phones are "absolutely safe" or "absolutely dangerous."  Most now recognize that cell phone radiation is biologically active and agree we need more research to determine in what ways it can be harmful to our bodies and how best to reduce risks.  Many scientists and health professionals recommend precautionary measures to the public. Some others who have conflicts of interest or interpret the data more conservatively tell their family members to take precaution.

Gupta: "We need 30 years of data to know for sure."

My comment:  Although scientific consensus takes a long time, Dr. Gupta's contention that we need 30 years of data is speculative. 

We have had evidence of harm to humans from exposure to low intensity microwave radiation for about 40 years. Allan Frey reported in the Annals of the New York Academy of Sciences in 1975 that 1900 MHz microwaves pulsed at certain modulations induce blood-brain barrier leakage in humans. 

We now have evidence of increased brain tumor risk associated with cell phone use from multiple case-control studies. We have also begun to see increased incidence of certain brain tumors in some countries. There is now considerable evidence of sperm damage in humans and some evidence of increased male infertility associated with cell phone use.

To put this in perspective, in 1912 a monograph documenting a strong link between cigarette smoking and lung cancer was published.  Fifty two years later, in the 1964 report to the Surgeon General smoking was recognized to cause lung cancer in men and probably cause it in women. 

Given how widespread cell phone use is and the fact that many children, teenagers, and pregnant women now use cell phones, it would be irresponsible for us to wait for scientific consensus that we have conclusive evidence of harm to humans before adopting precautionary measures.

Gupta: The Interphone Study found an increase in one type of brain tumor after 10 years.

My comment: The 13-nation Interphone Study paper reported an increase in glioma, a malignant brain tumor, for those who used cell phones for 1,640 or more hours in their lifetime. Many of these people used cell phones for less than 10 years. The paper also found a dose-response effect in terms of the number of years since the cell phone was first used (see Appendix 2).  Lennart Hardell's research in Sweden has obtained similar results.

Gupta: Fact: "Cell phone radiation is regulated by the government."  The government was looking at people who used their cell phones once a week for 6 months. Not a good standard for people who were more regular cell phone users.  It applied to adults.

My comment: This is incorrect. Although the government regulates cell phone radiation, the FCC's regulatory standard was developed by industry and does not assume once a week cell phone use. See my critique of the GAO Report for a discussion of how the standard was developed, and why it is inadequate.

Gupta: Fact: "In your cell phone instructions, there's a warning to keep the phone a certain distance from your body."  There are very specific warnings about minimum distance, e.g. the Blackberry is about 3/4 of an inch. 

My comment:The manufacturers' warnings vary from 5/8 of an inch (15 mm) to 1 inch (25 mm). More importantly, these minimum distances are inadequate as they assume that the only harm from cell phones is due to heating tissue which is not true. Furthermore, the standard is based on large males and is not adequate for others, especially women and children.

Gupta: The amount of radiation absorbed by a child is more. He showed Om Gandhi's slide comparing absorption in users of different ages. 

My comment:  Excellent point. The testing procedures established by the FCC employ a simulated head from a 6 foot 2 inch, 220 pound male. Most people's heads absorb far more radiation.  Moreover, individuals with metal fillings or braces on their teeth and those who wear metal eyeglass frames will be exposed to more radiation.

Gupta: Fiction: "Cell phones emit the same kind of radiation as X-ray machines." Non-ionizing radiation is like a microwave oven.  You don't want to hold a microwave oven by your head.  

My comment: This is not a good analogy as the radiated power of a cell phone is much less than a microwave oven.  Moreover, the harm from cell phone radiation exposure is not likely due to heating tissue but through sub-thermal mechanisms.

Oz: We don't have long-term data. There are flaws in studies. What should we do?

Gupta: I always use a wired earpiece. I think about not giving my kids cell phones. If you're having a hard time hearing, the phone emits more radiation, make the call another time.

My comment: These are good, basic precautionary messages. Other messages should include: 1) turn off your phone when not using; 2) never put the phone to your ear - use a headset, especially a corded device, or other hands-free method such as a speakerphone or text; 3) keep away from the head, eyes, salivary glands and reproductive organs – never in your pants pockets; and 4) use by pregnant women, children and teenagers should be extremely limited.