For years, debate has raged as to whether the electromagnetic fields and radiation emitted by mobile phones pose a health risk to humans—not so much because the levels are all that high, but because untold millions of individuals spend hours a day holding these radiation-emitting devices as close to their brains as is humanly possible. Although research is still ongoing and scientific studies so far have generally been regarded as inconclusive, the International Agency for Research on Cancer today waded waist-deep into the controversy: a team of scientists decided to list mobile phones in the same category of “carcinogenic hazard” as things like engine exhaust, chloroform, and lead (PDF) based on an increased risk for a malignant type of brain cancer.
The announcement comes from a team of 31 scientists from 14 countries, based on peer review of a number of studies on cell phone safety, including studies that are in-press and not yet available to the general scientific community. The listing puts mobile phones into “category 2B” items that are “possibly carcinogenic to humans.” The review found there was limited association between the use of wireless phones and both glioma and acoustic nueroma, and inadequate information for drawing conclusions for any other types of cancer. The group did not make any effort to quantify the risk, but notes that a 2004 study found a 40 percent increased risk for gliomas amongst people who used a mobile phone for 30 minutes a day over a 10-year period.
“Given the potential consequences for public health of this classification and findings, it is important that additional research be conducted into the long‐ term, heavy use of mobile phones,” said IARC Director Christopher Wild in a statement. “Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands‐free devices or texting. ”
As recently as this month, the World Health Organization claimed no adverse health effects from mobile phone use had been established.
The IARC assigns ratings to agents from 1 to 4, with substances rated a 1 known to be carcinogenic to humans (like asbestos and tobacco), and agents rated a 4 being “probably not carcinogenic” to humans. Group 3 agents aren’t classifiable as carcinogenic (usually due to insufficient evidence either way). Group 2 has two sub-categories: 2A, where an agent is deemed “probably carcinogenic,” and 2B, where an agent is deemed “possibly carcinogenic.” Agents in category 2B—now alongside cellphones—include things like gasoline, welding fumes, engine exhaust, vinyl acetate, and DDT. Also classified 2B: coffee and some forms of pickled vegetables.
Many long-term studies of cell phone use have been controversial because they ask participants to accurately assess their levels of cell phone use as much as a decade ago, and both cell phone usage patterns and technology have changed radically over time—meaning it may not be possible to apply older research and usage data to current devices and behaviors. A decade ago, texting and hands-free calling weren’t as common as they are today; similarly, today’s mobile phones tend to emit less microwave radiation than earlier handsets—although virtually all phone manufacturers recommend users hold the devices at little a little bit away from their heads when in use.