Nursery Schools: Characterization of heavy metal content in indoor dust

Abstract

Interior floor dust is found to be one of the major pathways of childhood exposure to indoor air pollutants. This study aims to carry out a general survey of heavy metals (Al, Ba, Cr, Cu, Fe, Ni and Pb) contamination at selected nursery school buildings in Shah Alam, Selangor and to study their relationship with the surrounding environment. The samples were collected using a brush and a plastic dustpan, after which the samples were digested using the wet digestion method. The heavy metal concentration was determined by an inductively coupled plasma - optical emission spectrometer (ICP-OES). The results show that the heavy metal concentrations at the nursery school building were in the range 901.2 - 1510.0, 13.3 - 76.7, 12.0 - 22.6, 22.2 - 42.7, 1489.0 - 7919.0, 5.5 -14.4, 13.2 - 64.6, 93.3 - 220.4mg kg-1 for Al, Ba, Cr, Cu, Fe, Ni and Pb respectively. The heavy metal concentration in the investigated areas followed the order Fe > Al > Zn > Pb > Ba > Cu > Cr > Ni. Principal Component Analysis (PCA) was carried out to ascertain the possible contributing factors towards the metal concentrations and thereby determine which metals have a common origin. PCA analysis indicated that three factors indicated sources of mixed origin including mobile vehicles, street dust and natural sources.