The document discusses possible links between cellphone use and tumors. It explains how cellphones work using radio frequency (RF) waves, which are a form of non-ionizing electromagnetic radiation. While RF waves do not destroy DNA like ionizing radiation, they can raise body temperature at higher levels. Some studies have found possible associations between heavy long-term cellphone use and certain types of brain tumors, but the evidence is limited and inconclusive. More research is still needed to determine if cellphones pose any health risks.