Witnesses testified about research into cellular telephone use and its potential impact on human health, as well as the potential side effects and consequences of cell phone use. They focused on studies that had examined potential links between cell phones and cancer, and about warnings issued by some groups on cell phone safety.
Many studies related to the effects of cell phone use on health is contradictory, but more recent epidemiological studies involving humans suggest that heavy cell phone users of 10 years or more have developed brain tumors on the same side of their heads as where they used to hold their mobile phones.