|Proven: Cellphones Affect Human Brains. Harm, If Any, Unproven.|
|Written by Dave Burstein|
|Tuesday, 22 February 2011 19:21|
Dr. Nora Volkow, a world class neuroscientist, uses a headpiece for her mobile phone. While her article in The Jaournal of the American Medical Association is clear she found absolutely no evidence of harm, she wants to be "conservative."
Her work at NIH does provide remarkable evidence that the brain responds to cell phone signals. It is now almost certainly untrue to say, as cellphone company's spokesmen often do, that there is no proven effect of cellphones on human brains. Tara Parker-Pope in the New York Times illustrated the story with original scans from the JAMA article, abstract below. The picture on the left is a PET scan with cell phones turned off. The picture on the right is the same, with cell phones turned on but muted. The person didn't know when the phones were on or off.
The reddish areas and the expanded yellow areas on the right are increased brain activity when the cellphone is on and held near the ear. Personally, I'm not giving up my cellphone. I'm guessing there is no significant harm, but that's clearly unproven.
CTIA's Steve Largent usually speaks for Verizon and AT&T on this issue, including suing the city of San Francisco for requiring mobile phone dealers to reveal the radiation measured by the phones they sell. Largent wrote, “CTIA and the wireless industry are deeply committed to safety and to providing timely, accurate information to consumers about wireless phones." (Release below and additional statement below.)
Volkov has an interesting discussion on her previous work on brain imaging, dopamine and addiction. She did pioneering work on the neuro effects of cocaine.
JAMA. 2011;305(8):808-813. doi: 10.1001/jama.2011.186
Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism
1. Nora D. Volkow, MD;
2. Dardo Tomasi, PhD;
3. Gene-Jack Wang, MD;
4. Paul Vaska, PhD;
5. Joanna S. Fowler, PhD;
6. Frank Telang, MD;
7. Dave Alexoff, BSE;
8. Jean Logan, PhD;
9. Christopher Wong, MS
Author Affiliations: National Institute on Drug Abuse, Bethesda, Maryland (Dr Volkow); National Institute on Alcohol Abuse and Alcoholism, Bethesda (Drs Volkow, Tomasi, and Telang and Mr Wong); and Medical Department, Brookhaven National Laboratory, Upton, New York (Drs Wang, Vaska, Fowler, and Logan and Mr Alexoff).
Context The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain. However, whether acute cell phone exposure affects the human brain is unclear.
Objective To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity.
Design, Setting, and Participants Randomized crossover study conducted between January 1 and December 31, 2009, at a single US laboratory among 47 healthy participants recruited from the community. Cell phones were placed on the left and right ears and positron emission tomography with (18F)fluorodeoxyglucose injection was used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes (“on” condition) and once with both cell phones deactivated (“off” condition). Statistical parametric mapping was used to compare metabolism between on and off conditions using paired t tests, and Pearson linear correlations were used to verify the association of metabolism and estimated amplitude of radiofrequency-modulated electromagnetic waves emitted by the cell phone. Clusters with at least 1000 voxels (volume >8 cm3) and P < .05 (corrected for multiple comparisons) were considered significant.
Main Outcome Measure Brain glucose metabolism computed as absolute metabolism (μmol/100 g per minute) and as normalized metabolism (region/whole brain).
Results Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher for on than off conditions (35.7 vs 33.3 μmol/100 g per minute; mean difference, 2.4 [95% confidence interval, 0.67-4.2]; P = .004). The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism (R = 0.95, P < .001) and normalized metabolism (R = 0.89; P < .001).
Conclusions In healthy participants and compared with no exposure, 50-minute cell phone exposure was associated with increased brain glucose metabolism in the region closest to the antenna. This finding is of unknown clinical significance.
CTIA–The Wireless Association® Statement on “The Health Effects of Cell Phone Use” Hearing
September 14, 2009
WASHINGTON, DC – Today, CTIA-The Wireless Association® President and CEO Steve Largent issued the following statement in response to the U.S. Senate Subcommittee on Appropriations for the Departments of Labor, Health and Human Services, Education, and Related Agencies Hearing on “The Health Effects of Cell Phone Use:”
“CTIA and the wireless industry are deeply committed to safety and to providing timely, accurate information to consumers about wireless phones. When it comes to the facts about cell phones and health-related effects, the industry relies on the conclusions of impartial groups such as the U.S. Food and Drug Administration (FDA), the World Health Organization (WHO), the American Cancer Society, and the National Institute of Health, which have all concluded that the scientific evidence to date does not demonstrate any adverse health effects associated with the use of wireless phones.
“In July 2009, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) released a statement addressing the current scientific evidence concerning exposure to high frequency electromagnetic fields (EMF), including frequencies used for modern wireless communications. It said the scientific literature ‘provided no evidence of any adverse effects below the basic restrictions and does not necessitate an immediate revision of its guidance on limiting exposure to high frequency electromagnetic fields.’
“There has been significant research conducted on the issue of whether there is a link between wireless phone use and health effects. Much has been completed and more continues today. CTIA and the U.S. Food and Drug Administration recently examined scientific questions about radiofrequency (RF) energy pursuant to a Cooperative Research and Development Agreement (CRADA). The FDA, not industry, was responsible for the research performed under the CRADA.
“All wireless devices must adhere to strict emissions guidelines in the United States, which have been developed under a thorough and rigorous review process. All wireless base station antennas and phones must meet the science-based, RF emission guidelines of the Federal Communications Commission (FCC), which has established very conservative limits to ensure that the health of all citizens is protected. The FCC maintains a database that provides the SAR value for cellular phones sold in the United States.”.John Walls, vice president, public affairs for CTIA-The Wireless Association:
"In this study, published in JAMA, the authors acknowledge that the results provide no information as to potential health effects of cell phones. As with any study, scientific organizations will review the results of this one in the context of the significant body of research and published literature on cell phone safety that has already been amassed. This research includes the Interphone project, which was coordinated by the International Agency for Research on Cancer, is the largest study of cell phone use and brain tumors ever undertaken and included substantial numbers of subjects using cell phones for ten years or longer. Dr. Christopher Wild, Director of the International Agency for Research on Cancer, summarized the key finding of the study, stating: ‘An increase of brain cancer is not established from the data from Interphone.’ The research also includes a National Cancer Institute study tracking the incidence of brain cancer in the US during the period when cell phone use increased dramatically, which concludes that the data 'do not provide support for the view that use of cellular phones causes brain cancer.' And a similar study conducted in U.K. and published just this year concludes that the increased and widespread use of cell phones 'has not led to a noticeable increase in the incidence of brain cancer in England between 1998 and 2007.'
"CTIA and the wireless industry support continuing efforts of public health specialists and expert scientists in this area.
"All cell phones sold in the U.S. must comply with the FCC’s radiofrequency exposure standards, which are designed to include a substantial margin of safety for consumers. Numerous experts and government health and safety organizations around the world have reviewed the existing database of studies and ongoing research and concluded that RF products meeting established safety guidelines pose no known health risk."