Exposure of school children to particulate matter and inorganic gaseous pollutants in Hawassa city, Ethiopia

The detrimental consequences of air pollution on people, particularly vulnerable groups like children, have drawn a lot of attention globally. Studies on the levels and sources of particulate matter (PM_2.5 and PM₁₀) and inorganic gaseous pollutants (NO₂, CO, and SO₂) in primary schools in Africa, including Ethiopia, are scanty. Therefore, the objective of this study was to determine the levels of particulate matter and inorganic gaseous pollutants in primary schools in Hawassa, Ethiopia, and assess potential health risks. The levels of PM_2.5 and PM₁₀ were determined using a portable gas monitor device (HoldPeak Laser PM meter, HP 5800D), whereas NO₂, CO, and SO₂ levels were determined using the Aeroqual Series 500 Portable Air Quality Monitor (Aeroqual Ltd., New Zealand). The levels of PM_2.5, PM₁₀, and NO₂ in all sampling sites ranged from 11–66.3, 30.8–399.7, and 60.5–152 µg/m³, respectively. The levels of PM_2.5 and PM₁₀ were found to be above the World Health Organization recommendations in 55% and 85% of the sampling sites, respectively. The hazard quotient (HQ) values for PM₁₀ and PM_2.5 ranged from 0.3 to 3.2 and 0.2 to 1.1, respectively. The Air Quality Index (AQI) at 40% and 30% of the outdoor sampling sites was unhealthy for sensitive groups due to exposure to PM_2.5 and PM₁₀, respectively. The levels of PM_2.5 and PM₁₀, as well as the AQI and HQ values, indicate a poor condition of the air in the schools, especially in the schools near busy traffic roads.