Since cell phone technology is rapidly expanding but still relatively new, concern about its long-term effects on human health is on the rise. Researchers have speculated that cancer, interrupted sleep, blood-brain barrier leakage, neurobehavioral problems, and headaches can be linked to cellphone use, but scientific studies have produced varying results. However, a new study conducted at Yale University has given pregnant women, specifically, good reason to limit their exposure; it provides the first scientific evidence linking in-utero cell phone radiofrequency exposure to symptoms of ADHD.
Effects of Cell Phone Radiation In-Utero
Researchers published their findings in Scientific Reports in March 2012. They exposed 33 pregnant mice to active cell phones, placed over their cages on uninterrupted, muted calls, throughout days 1-17 of gestation (gestation for mice lasts 18-20 days) (Aldad, 2012). A control group of 42 pregnant mice were kept in the same conditions without exposure to cell phone radiation.
After the mice gave birth, several tests were performed on the offspring to observe their behavior for symptoms of ADHD: poor memory due to inattention, impulsivity, and hyperactivity. According to their report, researchers concluded that, “Overall, the mice exposed in-utero to radiation were hyperactive, and had decreased memory.”
Because this is the first study of its kind, further investigation is needed to determine the exact impact in-utero radiation exposure can have on a human fetus. The scientists at Yale recommend testing humans and other primates, since the rate of brain development is different in mice than in humans. This could potentially reveal a difference in vulnerability between mouse and human fetuses. Additionally, they recommend testing during various stages of gestation to determine when a fetus is at the highest risk for behavioral issues due to cell phone exposure.
Cell Phone Radiation and the Brain
Scientists working with human subjects have also found evidence that cell phone electromagnetic frequencies can alter brain activity. A study published in The Journal of the American Medical Association in February 2011 showed that whole-brain glucose metabolism (a marker of brain activity) significantly increases in areas closest to the cell phone antenna (Volkow, 2011).
Dr. Nora D. Volkow, Director of the National Institute on Drug Abuse in Bethesda, Maryland, led a study involving 47 healthy, randomly selected participants. Cell phones were fixed to both of the participants’ ears while turned off, and their glucose metabolism was measured using a PET scan. Then, the phone on the right ear was placed on a silenced call and another PET scan was completed. Dr. Volkow concluded: “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.”
Volkow clarifies that this study is different from its predecessors because it uses glucose metabolism as a measure. Previous studies have commonly measured changes in cerebral blood flow due to cell phone exposure via PET scans. Those small-scale studies have produced inconsistent results. Glucose metabolism is a more sensitive marker; it indicates changes in brain activity with a lesser chance of misunderstanding where the brain’s signals originated.
With a reliable marker showing functional brain changes in adults during a 50-minute call, is it plausible that exposing a fetus during its development could put it at greater risk? The scientists behind the Yale study think so. They cite X-rays, alcohol, drugs, and even stress as environmental toxins capable of harming a fetus much more than they would an adult.
“It is therefore not surprising,” they say, “that studies exposing adult animals to radiofrequency radiation failed to find similar significant defects in behavior. The exposure to cellular telephones in pregnancy may have a comparable effect on the fetus…as do exposures to other common neurodevelopmental toxicants.”
Yale researchers also directly examined the brains of the mice they’d studied to determine if in-utero exposure had led to effects beyond the cerebral cortex. They determined that, in deed, changes were not limited to the cortex, “indicating that in-utero exposure to radiofrequency is a potential cause of neurobehavioral disorders.”
Warnings from Cell Phone Makers
Cell phone manufacturers insist that their products fall within FCC-regulated standards for radiation (measured by “specific absorption rate,” or SAR). They manage to meet the standards by including a warning in user manuals recommending that users who store their phones on their bodies while they are on use a manufacturer-approved holster to shield them from excess radiofrequency emissions.
The Samsung SCH-u310, the basic flip-phone used in Dr. Volkow’s study, has this in its manual: “This phone…meets FCC RF exposure guidelines when used with an accessory that contains no metal and positions the handset a minimum of 1.5 cm from the body. Use of other accessories may not ensure compliance with FCC RF exposure guidelines.”
But with the rise of smartphones, basic flip-phones are losing ground. Apple says in its published user information, “SAR levels experienced during normal use [of the iPhone] may be lower than the maximum SAR levels.” With that message is the standard recommendation to keep the phone roughly an inch away from your body when its power is on.
Significantly, this information is not in the iPhone user manual. Users can find it in a separate, fine-printed manual (a 2.5” tome containing up to 500 words per page) entitled “Important Product Information Guide.” It can be accessed on their website or through the iBooks application.
Makers of the BlackBerry Curve 8520/8530 even see the need to address in-utero exposure in their safety guidelines: “Use hands-free operation if it is available and keep the BlackBerry device at least 0.98 in (25 mm) from your body (including the abdomen of pregnant women and the lower abdomen of teenagers) when [it] is turned on and connected to the wireless network.”
Although there are warnings in place, the researchers at Yale emphasize the importance of further study. They hope to see new regulations to protect developing human fetuses from radiofrequency exposure. They say that, “The rise in behavioral disorders in developed countries may be, at least in part, due to a contribution from fetal cellular telephone radiation exposure. Further testing is warranted…to determine if the risks are similar and to establish safe exposure limits during pregnancy.”