Microanalysis of the Floor Dust Particles in the Classrooms of Tropical Urban Environment

Floor dust particles collected from schools located in tropical urban India were analyzed for morphological characteristics, heavy metals and for assessing the associated health risks. The floor dust particles were collected twice each day (before and after teaching hours) for 12 days from each microenvironment for the analysis. The morphological characteristics of dust particles were found to differ from schools to schools due to their contrasting locations. The total average concentrations of heavy metals such as Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn were found to be higher in KV IIT (school in urban background) (414 ± 182 mg kg−1), followed by KV CLRI (school in urban roadside) (319.8 ± 162.3 mg kg−1) and MGHS (school in industrial area) (96.45 ± 27.93 mg kg−1). Chalk dust, crustal sources, and vehicular exhaust emissions were the significant contributor to floor dust in schools. Health risks of toxic heavy metals due to ingestion, inhalation and dermal contact exposure to school children were assessed. Health risk assessment results indicated that dermal contact exposure to Ba, Cu, Pb, and V could develop non-cancer risks among school children. The inhalation cancer risks of Co, Cr, and Ni were found to be within safe limits.