Assessment of Indoor Air Pollution through Fine Particle Capturing Potential and Accumulation on Plant Foliage in Delhi, India

Abstract

The dry deposition of PM on foliage of indoor plants in the households of Delhi has been reported in this study. It was observed that dustfall fluxes were higher at the industrial site (MH) as compared to the residential site (DH). Seasonal variations in dust deposition indicated that it was highest in the winter season and lowest in the monsoon season. Chemical profiling of the deposited dust marked that dust was less basic at MH as compared to DH and Ca2+ was ubiquitously the most abundant cation at both sites whereas Cl- and SO42- were the most abundant anions at DH and MH, respectively. Abundance of K+, NO3- and NH4+ etc. indicated the influence of anthropogenic activities. The number of PM deposited on the foliar surfaces of indoor plants was also estimated and divided into PM1, PM2.5 and PM10 based on their size because particle count is more appropriate than particle mass for estimation of finer PM. PM accumulation on the foliar surfaces of selected plants for the present study followed the order, PM1 > PM2.5 > PM10 at both the sites. The foliar micromorphology of abaxial surfaces of the plants accounted for significant interspecies variability due to difference in presence of grooves and undulations, high stomatal density, epicuticular wax etc. Leaves with densely arranged grooves and ridges showed more PM accumulation. Investigation of plants with respect to dust deposition and selection of species which can perform the dual functions of improving air quality and providing aesthetic value are needed for understanding the role of vegetation in air pollution mitigation approaches in real life environment.