Volatile organic compounds in school environments of Hawassa city, Ethiopia and assessment of possible human health risks

Volatile organic compounds (VOCs) have become a major human wellbeing and environmental concern worldwide. However, evidence on VOC concentrations in primary school environments in Africa, including Ethiopia, is scarce. The goal of this research was to examine VOCs in primary schools in Hawassa, Ethiopia, and to evaluate possible health threats. Concentrations of 76 VOCs were investigated in air samples from classrooms and playgrounds of eight primary schools in Hawassa, Ethiopia. Air samples were taken via passive sampling method using Tenax TA as a sorbent and analyzed by using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Highest total VOCs (TVOCs) concentration (83 μg/m3) was observed in the classroom of School 2 followed by the classroom of School 1 (76 μg/m3), while the smallest TVOC concentration, 37 μg/m3 in the playground of School 8. Among the BTEX, toluene was the most dominant in all samples, ranging from 33% in School 4–38% in School 1 of ∑BTEX. I/O ratios of individual VOC in the schools ranged from 0.44 in School 4 to 9.21 in School 2. The highest cumulative cancer risk (CCR × 106) and the total hazard ratio indicator (THRI) values were 126 and 1.58E-01 respectively, in the classroom of School 4. The CCR and THRI values indicated that the exposure of children to the measured concentrations of benzene may have potentially harmful effects. •Concentrations of 76 VOCs were determined in schools from eight primary schools.•The highest TVOC concentration (83 μg/m3) was detected in a classroom.•Toluene was the most dominant BTEX across all sampling schools.•The values of CCR × 106 in the schools ranged from 70 to 126.•The values of THRI in the schools ranged from 7.72 E−02 to 1.58 E−01.