This review/overview argues that ultrafine particulate matter and industrial nanoparticles can reach the brain and accumulate in sleep and arousal regulatory regions, including orexinergic neuron hubs. It reports that ferromagnetic particles in these regions show motion responsive to low-intensity electromagnetic fields (30–50 μT) and describes links to sleep disturbances and neurodegenerative disease markers in young urban residents. The authors frame combined air pollution nanoparticle exposure and low-level EMF as a significant threat and call for monitoring and protective strategies.