Influence of exposure to coarse, fine and ultrafine urban particulate matter and their biological constituents on neural biomarkers in a randomized controlled crossover study.

•Healthy volunteers were exposed to filtered clean air, and coarse, fine and ultrafine particles coming from outdoor air.•Endotoxin and β-1,3-D-glucan in the particles, and neural biomarker levels in blood and urine were measured.•Associations between exposure to particulate matter and changes in neural biomarkers were examined.•Coarse particles and its biological constituents may influence perturbations of blood-brain barrier and systemic stress.