Environmental pollutants and brain cancers: where do we stand?
The global burden of Tumors of the Central Nervous System has increased in the past 25 years. Their prognosis is usually poor, and the less aggressive tumors can lead to severe cognitive and physical disabilities.
The etiopathogenesis of CNS tumors is still largely unknown. Genetic factors and ionizing radiation are currently the only well-established risk factors for brain tumors. Several compounds present in the environment have been studied as possible causative agents of CNS tumors, often with inconclusive results. In this review, we focus the attention on certain categories of environmental pollutants for which new data emerged in the recent years, possibly integrating and reinforcing the actual hypothesis that links these factors to brain tumors. Pollutants are present in the environment as a result of both natural phenomena and human activities. We review the role that some categories of pollutants, such as particulate matter, heavy metals, pollutants in the food chain production, and electromagnetic fields may have in the onset of brain tumors. Although many evidences suggest a possible association between specific pollutants and some brain tumors, a clear associative role has not been established yet.
The lack of strong causality between environmental exposures and brain cancer has hampered ability to support risk assesments and actionable policies, however recent well-controlled epidemiologic studies suggest correlations worthy of additional in-depth cosiderations.