Exposure to electromagnetic fields and cancer: The epidemiological evidence

There is still an ongoing scientific controversy whether exposure to electromagnetic fields is associated with an increased cancer risk in humans. Epidemiological studies have shown a consistent association between exposure to extremely low-frequency (ELF) magnetic fields and the risk of leukemia in children, but even after decades of investigations it is unclear whether the observed association is causal or due to bias and limitations of the studies. The International Agency for Research on Cancer (IARC) has therefore classified ELF magnetic fields as possibly carcinogenic to humans. Several studies of different designs investigated the association between radiofrequency (RF) electromagnetic fields related to the use of cellular telephones and the risk of brain tumors. While short-term use of cell phones of less than ten years was not related to any increased tumor risk, uncertainty remains particularly for longer term heavy users. Cell phone studies are methodologically challenging and future study protocols need to reduce limitations observed in studies available today.