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

ABSTRACT

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, PM_2.5, 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

KEYWORDS:

• Indoor air quality
• FTIR
• FESEM
• dust characterization
• volatile organic carbon
• India

Highlights

• Characterization of settled dust was performed using FESEM, EDX, and FTIR analysis.

• Alkyl Halide (C–F) and Alkane (C–H) confirmed the presence of VOC in indoor dust.

• PM₁₀ and PM_2.5 concentrations exceeded the permissible limits of WHO guidelines.

• Strong correlation found for C with S, O with Si, and Ca, O with Fe, respectively.

Acknowledgements

The authors would like to acknowledge Department of Environmental Science and Engineering, Indian School of Mines, Dhanbad, India for providing necessary facilities for this research. Authors would also like to acknowledge to the occupants of the different indoor and outdoor environment for their help in sample collection and monitoring.

Supplementary material

Supplemental data for this article can be accessed here.