Characterisation of Indoor PM10 in Residential Areas of Delhi

Abstract

The relationship between indoor and outdoor concentrations of fine and coarse fractions of PM10 with respect to their chemical composition was investigated simultaneously at two different localities in Delhi. Indoor and outdoor aerosol samples for the fine fraction (with an aerodynamic diameter less than 2.1 μm) and coarse fraction (with an aerodynamic diameter between 2.1–10 μm) were collected simultaneously from inside and outside of two different houses in two different types of localities for the period of January to June 2000. The average contribution of the fine fraction indoors for Sites I and II respectively was 51 and 53% of the total PM10 and outdoors was 43 and 41%. The highest outdoor concentration of PM10 was recorded in the month of May/June at both sites. The reason for the higher values in the months of May/June could be the frequent pre-monsoon dust storm events commonly called ‘‘Andhi’’ in India, which generally carry loads of fine dust from the neighbouring Thar Desert to Northern India before the onset of the monsoon.