School absenteeism linked to PM _2.5 and SO ₂ exposure in students with asthma from environmental justice areas with elevated AQI risk

The objective of this study was to examine the influence of air quality (PM_2.5, SO₂, O₃, and NO₂) on daily school absenteeism rates in students with and without asthma in an underserved community with elevated exposure risk. This retrospective study analyzed daily attendance and OAP exposure data from 2015/16 to 2017/18 in an environmental justice area located in Pittsburgh, Pennsylvania. For students with asthma, both long-term (28-day) and short-term (previous day) exposure to these PM_2.5 levels 10.0-12.0 μg/m³ significantly increased absenteeism compared to days with levels below 10 μg/m³ (RR = 1.27, 95% CI 1.10, 1.45 and RR = 1.21, 95% CI 1.03, 1.42, respectively, <i>p</i> < .05). Exposure to unhealthy SO₂ levels (≥75 ppb) also contributed to increased absenteeism (RR = 1.85, 95% CI 1.17-2.92, <i>p</i> < .05). These findings suggest that, while the EPA's recent reduction in the PM_2.5 good air quality standard threshold to 9 μg/m³ represents an important step toward protecting sensitive groups, it does not fully safeguard children in areas prone to frequent exceedances. The study underscores the importance of reducing exposure to outdoor air pollutants in at-risk populations, as inequities in childhood exposure can persist throughout life and disproportionately impact marginalized communities.