Characterization and morphometric study of household settled dust: A case study in Dhanbad, the coal capital of India

This study is designed to determine the morphology, elemental composition, and identification of various minerals and functional groups in household dust in multiple locations in Dhanbad, India. Household dust samples were collected from different locations, and samples had been sieved for particle sizes of < 75 mu m for analysis. For indoor air quality, active PM sampling for each sampling site was done and concentrations of PM10, PM2.5, and PM1 were observed in the range of 31-137, 23-82, and 17-52 mu g/m(3), respectively. The morphology (FESEM) and elemental analysis (EDX) confirmed the existence of particles with different shapes and compositions in different households. Spherical shape and chain-like structures are indicative of coal combustion inside houses. In contrast, irregular-shaped structures with sharp-edged and sheet-like structures suggest mineral-rich crustal dust in LPG-based houses. Also, soot agglomerates were found in houses nearby roadside from outside vehicular emissions. Energy-dispersive X-ray spectroscopy (EDX) confirmed the relative distribution of elements varied between households and reported that C, O, Mg, Ca, Al, and Si were the primary elements in dust samples collected from various households. The Fourier Transform Infrared (FTIR) peaks for functional groups at various wavelengths such as -C-H, -C=C, -C=O, -C-X indicates coal dust and their combustion whereas -NH2, -NH4+, -R-SO3- suggests the influence of walking, cleaning, and other household activities. X-ray diffraction (XRD) confirms that minerals such as calcite, vaterite, and quartz were found majorly in roadside houses whereas dolomite, quartz, and hematite were in other sites.