Using low-cost sensors, PM_2.5 pollution exposure was monitored throughout the course of a typical school day for two children from different socioeconomic backgrounds in New Delhi, India. Monu, 13, lives in a hut in a slum near the polluted Yamuna River in New Delhi, does not have access to air purifiers, and experiences about four times as much air pollution in a day than 11-year old Aamya, who lives in an upper-middle-class neighborhood and has access to air purifiers at both home and school. Learn more