The World Health Organization (WHO) has classified the radiation from mobile phones in the same “possibly carcinogenic” category as, for example, chloroform, lead and exhaust gases produced by engines.

Cancer is one of the most discussed impacts from everyday radiation. Evidence has been found of relationships with multiple types of cancer including breast cancer, hematological cancers, and brain cancer.

The largest study of cell phone use and brain cancer is the Interphone Case-Control Study involving 13 developed countries except the U.S. While the increased risk of brain cancer was not established from this study of 30-59 year-olds brain cancer patients, the research did show that people who used a cell phone for 10+ years had double the risk of developing brain gliomas, a type of tumor. The Director of the WHO’s International Agency for Research on Cancer (IARC) said, “Observations at the highest level of cumulative call time and the changing patterns of mobile phone use since the period studied by Interphone, particularly in young people, mean that further investigation of mobile phone use and brain cancer risk is merited.”

In May 2016, results from a multi-year, federally funded study by the National Toxicology Program showed that male rats exposed to radio-frequency (RF) radiation had a greater chance of being diagnosed with a brain cancer called malignant glioma, as well as developing a tumor found on the heart. The radiation levels the rats were exposed to were near federal safety limits similar to what humans would be exposed to.

A 2017 report in the American Journal of Epidemiology confirmed that Canadians who used cellphones for 558 hours or more in their lifetime have more than double the risk for glioma, an aggressive brain cancer. The findings strengthened the association between glioma and cell phone use.

Childhood leukemia and other hematological cancers (lymphoma and multiple myeloma) have been shown in multiple studies to be associated with low-frequency magnetic fields, such as those from power lines. A causal biological mechanism is not understood, but the association has been found to have strong statistical significance. In 2002, the IARC classified these magnetic fields as “possibly carcinogenic to humans,” based on the demonstrated “consistent pattern of a two-fold increase in childhood leukemia associated with average exposure to residential power-frequency magnetic fields.”