Medical Health Encyclopedia

The risk for primary brain tumors in Caucasians is higher--as much as twofold depending on type--than in African Americans.

Environmental or Occupational Risk Factors

Radiation. The only proven risk factor for brain tumors to date is high-energy radiation from ions (such as with radiation treatment).

Studies on the effects of lower-energy radiation, such as microwaves and electromagnetic fields, have been uncertain. One study reported that men whose jobs exposed them to electromagnetic fields had higher rates for brain cancer, although a more recent study found a higher risk only in men who were also exposed to chemicals (petroleum, solvents, lead, pesticides and herbicides).

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A 2002 study on Korean War veterans highly exposed to microwaves from radar equipment reported no excess risk for brain cancer--or any other malignancy--over a 40-year period. Studies in both 2000 and 2001 found no evidence to suggest a higher risk with cellular phones and other wireless devices that use radiofrequency.

Chemical and Metals in Brain Tumors. High exposure to a number of metals and chemicals have been associated with brain tumors, such as the following:

• High exposure to certain chemicals, including vinyl chloride and petroleum products, has been associated with brain tumors.
• High levels of lead, arsenic, or mercury exposure have been linked to a higher risk. One study suggested that lead exposure was particularly associated with meningiomas. It is unknown whether these associations are real, and confirmatory studies are needed.
• There has been some suggestion of a higher risk with exposure to pesticides.A major study of pesticides is underway, but results are not in yet. A 2003 study indicated that parental exposure to pesticides or herbicides did not appear to be important in increasing risk for brain cancer in their children.