BIOAVAILABILITY AND HEALTH RISK OF METALS IN URBAN DUSTS

Abstract

Heavy metals gets into human body mostly through oral ingestion of environmental samples. To quantify the risks associated with oral ingestion of urban dust particularly by children, bioavalability fraction is required, as the total metal content may not give the real risk involved. Lead (Pb), Arsenic (As) and Cadmium (Cd) were analysed for bioavailable fraction in urban dust of this study. The risks of these metals on ingestion of urban dust by children were estimated. The results showed that metals solubilized in the gastrointestinal tract. This could possibly be due to metal distribution in the dust sample and the solubilisation of these metals in the gastrointestinal tract. The carcinogenic and non-carcinogenic risks results expressed that all the values were within the permissible limits of 1×10-6 1×10-4 with the order As > Cd > Pb. This indicates that children who ingested dust could have no possibility of both carcinogenic and non-cancer risks because both the CR, TCR and HQ and HI values were below the tolerable limits. Keywords: Bioavailability; risks; metals; urban dust