Table 2

Summary of environmental risk factors for brain tumours investigated in epidemiological studies

FactorSpecific aspectsEvaluation of risk
▸ Ionising radiationTherapeutic, diagnosticTherapeutic doses increase risk but diagnostic x rays do not appear to be associated
▸ Mobile phonesRadiofrequency exposureCurrent epidemiological and biological evidence does not support any link between mobile use and the risk of brain tumours
▸ Extremely low frequency electromagnetic fieldsResidential and occupational exposureLittle consistent evidence but research is ongoing
▸ Specific infectionsViruses, Toxoplasma gondii, in utero influenza and varicellaNo candidate viruses consistently associated or found in tumour tissue. Few links to in utero exposure
▸ AllergiesAtopyThe presence of atopy appears to be protective but further work needed to identify mechanisms
▸ DietNitrosamine/nitrosamide/ nitrite/nitrate consumption. AspartameNo consistent evidence
▸ TobaccoCigarettes, cigars, pipesNo associations
▸ AlcoholNo associations
▸ Chemical agentsHair dyes, solvents, pesticides, traffic related air pollutionNo consistent evidence
▸ OccupationsRubber manufacture, vinyl chloride, petroleum refiningSmall risks associated with working in the petroleum/oil industry but no mechanism or specific chemical known
▸ Head trauma/injuryNo consistent evidence