Characterization of indoor settled dust and investigation of indoor air quality in different micro-environments.

Present study reports the characterization results of settled dust particles in different indoor micro-environments of an academic institution in India. Field emission scanning electron microscope analysis of indoor dust revealed the presence of mineral particles, fly ash, and soot particles of different morphologies. Energy-dispersive X-ray spectroscopy analysis of indoor dust indicated that crystal particles are comprised of elements such as C, O, Na, Mg, Al, Si, S, Cl, K, Ca, Fe, and Ti. These elements accounted for more than 99% of the samples. The average content of O (42.7%) and C (18.9%) in the dust particles was found to be higher than their natural abundances. The concentrations of PM10, PM2.5, and PM1 were observed in the range of 88-58, 37-33, 23-29 µg/m3, respectively. Except temperature, other parameters such as volatile organic carbon, carbon dioxide concentration, and relative humidity were found to be within comfort limits of American Society of Heating, Refrigerating, and Air-Conditioning Engineers. ABBREVIATIONS: ASHRAE: American Society of Heating, Refrigerating, and Air-Conditioning Engineers; CO2: carbon dioxide; COPD: chronic obstructive pulmonary disease; EDX: energy-dispersive X-ray; FESEM: field emission scanning electron microscope; FTIR: Fourier transform infrared spectroscopy; IAP: indoor air pollution; IAQ: indoor air quality; HAP: household air pollution; OAP: outdoor air pollution; PM: particulate matter; VOC: volatile organic carbon; WHO: World Health Organization.