Summary of environmental risk factors for brain tumours investigated in epidemiological studies
| Factor | Specific aspects | Evaluation of risk |
|---|---|---|
| ▸ Ionising radiation | Therapeutic, diagnostic | Therapeutic doses increase risk but diagnostic x rays do not appear to be associated |
| ▸ Mobile phones | Radiofrequency exposure | Current epidemiological and biological evidence does not support any link between mobile use and the risk of brain tumours |
| ▸ Extremely low frequency electromagnetic fields | Residential and occupational exposure | Little consistent evidence but research is ongoing |
| ▸ Specific infections | Viruses, Toxoplasma gondii, in utero influenza and varicella | No candidate viruses consistently associated or found in tumour tissue. Few links to in utero exposure |
| ▸ Allergies | Atopy | The presence of atopy appears to be protective but further work needed to identify mechanisms |
| ▸ Diet | Nitrosamine/nitrosamide/ nitrite/nitrate consumption. Aspartame | No consistent evidence |
| ▸ Tobacco | Cigarettes, cigars, pipes | No associations |
| ▸ Alcohol | No associations | |
| ▸ Chemical agents | Hair dyes, solvents, pesticides, traffic related air pollution | No consistent evidence |
| ▸ Occupations | Rubber manufacture, vinyl chloride, petroleum refining | Small risks associated with working in the petroleum/oil industry but no mechanism or specific chemical known |
| ▸ Head trauma/injury | No consistent evidence |