Health benefits to vulnerable populations by meeting particle-level guidelines inside schools with different ventilation conditions.

We conducted simultaneous real-time measurements for particles on the premises of four schools, two of which were naturally ventilated (NV) and two mechanically ventilated (MV) in Kanpur, India. Health to school children from reduced particle levels inside classrooms simulated to the lowest acceptable levels (ISHRAE Class C: PM10 ≤ 100 µg/m 3 & PM2.5 ≤ 25 µg/m 3 ) using air filters were examined. Lung deposition of particles was used as a proxy for health impacts and calculated using the MPPD model. The particle levels in all classrooms were above the baseline, with NV classrooms having higher particle masses than MV classrooms: 72.16% for PM 1 , 74.66% for PM 2.5 , and 85.17% for PM 10 . Our calculation reveals a whooping reduction in particles deposited in the lungs (1512% for PM 10 and 1485% for PM 2.5 ) in the case of the NV classrooms. Results highlight unhealthy air inside classrooms and suggest urgent interventions, such as simple filtration techniques, to achieve acceptable levels of particles inside schools.