Long-term exposure to ambient air pollution and incidence of brain tumours: The Danish Nurse Cohort

[Display omitted] •Air pollution might cause brain tumours, but literature is sparse and inconclusive.•We found weak positive associations of PM2.5 and NO2 with brain tumours incidence.•Associations were strongest for tumours located in the meninges and for benign tumours.•Association of PM2.5 with brain tumours was significantly enhanced in obese women. Air pollution has been considered a potent environmental risk factor for neuropathology through neuroinflammation and oxidative stress, which might also cause brain tumour formation. However, epidemiological evidence on the association between air pollution and brain tumours in humans is sparse, with no data on exposure to particles. In this study we aim to examine associations between long-term exposure to ambient air pollution and risk for development of brain tumours. We used the Danish Nurse Cohort with 28,731 female nurses (age≥44years) recruited in 1993 or 1999 when self-reported information on lifestyle was collected. We obtained data on the incidence of brain tumours until 2013 from the Danish Cancer Register, and estimated annual mean concentrations of particulate matter with diameter