São Paulo's rail system serves Brazil's largest city through metro and suburban rail services, with connections between the networks. The first metro line opened on 14 September 1974. The historical case profile described metro Lines 1–5 totaling 65.9 kilometers and 58 stations, alongside CPTM Lines 7–12 totaling 260.8 kilometers and 93 stations. It also listed extensions and new lines then under construction and noted São Paulo Metro's participation in CoMET. Network figures reflect the original entry.
BIOSUN provides air treatment solutions for rail transit. Its Chinese project profile reports experience across more than 100 rail projects in China and overseas, with applications addressing airborne microorganisms, particles, chemical gases and emissions from interior materials in occupied transport environments.
Applications cover train interiors, platforms, station halls and public restrooms. BIOSUN applies PHOTOPLASMA technology to selected microbial, gaseous and particulate air treatment requirements. Performance should be assessed against the equipment specifications, relevant test reports and operating conditions.
