The widespread use of mobile phones has raised concerns about their potential health effects, specifically regarding breast cancer risk when carried in a bra. This concern stems from the close proximity of the device to breast tissue. Examining the science of cell phone emissions and current research helps address these concerns.
Understanding Cell Phone Radiation
Cell phones communicate by emitting radiofrequency (RF) energy, a form of non-ionizing radiation. RF energy is part of the electromagnetic spectrum, like FM radio waves and visible light. Unlike ionizing radiation, such as X-rays or gamma rays, non-ionizing radiation does not have enough energy to directly damage DNA or break chemical bonds within cells.
The primary biological effect of RF energy at levels emitted by cell phones is heating of tissue. While high levels of RF energy can cause significant heating and potentially lead to burns, the levels emitted by cell phones are generally low and are not known to cause a measurable increase in core body temperature. Cell phones operate within safety guidelines that limit RF exposure, preventing harmful heating.
Examining the Scientific Evidence
Research has extensively investigated the link between cell phone use and various cancers, including breast cancer. To date, large-scale, high-quality studies have not consistently demonstrated a causal link between cell phone use and an increased risk of breast cancer.
Some studies, including case reports, have raised questions about a possible association, especially when phones were routinely placed against the breast for extended periods. For instance, a 2013 case series reported on four young women who developed multifocal breast cancer directly under where they carried their phones in their bras for several hours daily over multiple years. Similarly, a 2020 case-control study from Taiwan suggested that excessive smartphone use, especially with close proximity to the breasts, might increase breast cancer risk. However, these types of studies, while providing intriguing observations, often have limitations, such as small sample sizes or reliance on participants’ recall of past phone use, which can introduce bias. Overall, the broader scientific consensus, based on comprehensive epidemiological studies, indicates no definitive evidence connecting cell phone radiation to breast cancer.
Expert and Health Organization Consensus
Leading health organizations worldwide have reviewed scientific evidence on cell phones and cancer risk. The Centers for Disease Control and Prevention (CDC) states no definitive scientific evidence links cell phone use to cancer, and more research is needed. Similarly, the National Cancer Institute (NCI) concludes current evidence suggests cell phone use does not cause brain or other cancers.
The U.S. Food and Drug Administration (FDA) also states scientific evidence has not linked RF energy exposure from cell phones to health problems at or below established limits. The International Agency for Research on Cancer (IARC), a component of the World Health Organization (WHO), classified radiofrequency electromagnetic fields as “possibly carcinogenic to humans” (Group 2B) in 2011. This classification indicates that a causal link is considered credible, but that chance, bias or confounding cannot be ruled out with reasonable confidence. However, a more recent WHO-backed review, which examined approximately 5,000 studies published between 1994 and 2022, found no increased risk of various cancers, including brain cancer, associated with exposure to radiofrequency electromagnetic fields from cell phones.
General Cell Phone Safety Practices
While no direct link exists between cell phone use and breast cancer, some practices can reduce radiofrequency energy exposure if desired. Using a hands-free headset or speakerphone increases distance from the phone, reducing exposure during calls. Texting instead of talking also keeps the phone away from your head and body.
Keeping the phone off your body, such as in a bag or backpack instead of a pocket or bra, minimizes direct contact. Phones emit RF energy even when idle as they search for a signal; turning the phone off or using airplane mode when not needed eliminates exposure. These simple measures can help address concerns about exposure to RF energy from mobile devices.