Air Quality outside Schools in Newcastle upon Tyne, UK: An Investigation into NO₂ and PM Concentrations and PM Respiratory Deposition

Air pollution is the principal environmental threat to public health in the UK. Ever-increasing evidence links ambient air pollutants, preventable diseases, and health inequalities. Children are particularly vulnerable to harmful effects due to their short height, developing lungs, and higher rate of respiration. Using data from air quality monitors around schools, we investigated 2018–2019 ambient NO2, PM10, PM2.5, and PM1 concentrations at 12 schools in Newcastle upon Tyne, UK. We compared findings with EU/UK air quality regulations and guidelines, identified patterns, and calculated PM respiratory deposition doses (RDDs). The range of annual average (AA) concentrations across the schools for the two-year period was 23.7–39.2 µg/m3 for NO2, 7.4–22.2 µg/m3 for PM10, 3.5–11.6 µg/m3 for PM2.5, and 1.7–9.0 µg/m3 for PM1. The highest PM RDD children were exposed to at school was 30 µg/h. One school’s AA NO2, two schools’ hourly PM2.5 averages, and one school’s 24-h PM10 averages exceeded EU/UK regulations. All schools exceeded WHO2005 24-h PM10 and PM2.5 guidelines in 2018, less in 2019. All 12 schools would have exceeded WHO2021 NO2 AA guidelines (10 µg/m3), 2 the WHO2021 PM10 AA (15 µg/m3), and 10 the WHO2021 PM2.5 AA (5 µg/m3). Evidence-based policy is required to improve school ambient air quality and reduce children’s exposure