2019 Yes https://linkinghub.elsevier.com/retrieve/pii/S0147-6513(18)31330-7 Othman, Murnira Asia Epidemiology Study Modeling Elementary (K-5) Particulate Matter (PM) Dust Fine particulate matter (PM 2.5) School environment Indoor and outdoor dust Health risk assessment This study showed that the average indoor and outdoor 24 h PM2.5 was 11.2 ± 0.45 µg m−3 and 11.4 ± 0.44 µg m−3 respectively. The 8 h PM2.5 concentration ranged between 3.2 and 28 µg m−3 for indoor and 3.2 and 19 µg m−3 for outdoor classrooms. The highest ion concentration in indoor dust was Ca2+ with an average concentration of 38.5 ± 35.0 µg g−1 while for outdoor dust SO42- recorded the highest ion concentration with an average concentration of 30.6 ± 9.37 µg g−1. Dominant trace metals in both indoor and outdoor dust were Al, Fe and Zn. Principle component analysis-multiple linear regression (PCA-MLR) demonstrated that the major source of indoor dust was road dust (69%), while soil dominated the outdoor dust (74%). Health risk assessment showed that the hazard quotient (HQ) value for non-carcinogenic trace metals was < 1 while the total cancer risk (CR) value for carcinogenic elements was below the acceptable limit for both indoor and outdoor dust through dermal and inhalation pathways, but not the ingestion pathway.