Physicochemical characteristics of PM2.5: Low, middle, and high–income group homes in Agra, India–a case study

The present study shows the current scenario of the aggregate relation between income and pollution at the household level. The indoor sampling of fine particulate matter was conducted in low– middle– and high–income group homes in Agra City, the North Central region of India. The mean indoor concentrations of PM2.5 were 46.7 μg/m3, 39.2 μg/m3 and 25.6 μg/m3 in low– middle– and high–income group homes respectively. The full–day variation revealed that the concentrations of fine particles were higher during morning and evening hours in all the three income group homes. The indoor meteorological parameters were also monitored. Using scanning electron microscopy coupled with energy dispersive x–ray spectrometer (SEM–EDS) chemical and elemental analysis of fine particles and their probable sources has been conducted in low– middle– high–income group homes. EDS spectra indicates the elemental composition of PM2.5 which can be distributed into following groups of particles i.e. C–O rich (54%), F rich (42%) and other (4%) in low–income group homes. In middle– and high–income group homes F rich (59–65%), C–O rich (32–37%) and other (3–4%) were observed in PM2.5. The SEM images of fine particles indicates that the particles are clustered into following groups i.e. aluminosilicates/silica particles, spherical carbon rich particles, nearly spherical fluorine rich particles, Mg–Si or Mg–Si–Al particles.