An Evaluation of Loading Rate of Dust, Pb, Cd, and Ni and Metals Mass Concentration in the Settled Surface Dust in Domestic Houses and Factors Affecting Them

Abstract

Interior and exterior measurements of surface loading rates for settled surface dust in domestic houses and the content of three metals — lead (Pb), cadmium (Cd) and nickel (Ni) — were conducted weekly during the autumn of 2007 in an urban area of Giza, Egypt. Surface mass concentrations of the metals were also calculated. Results revealed that the interior and exterior surface loading rates averaged 1.58 and 8.18 g m-2 per week, respectively. The interior surface mass concentrations of Pb, Cd, and Ni averaged respectively 311.18, 33.09 and 53.51 μg g-1, and their interior surface loading rates averaged 533.17, 54.78 and 87.84 μgm -2 per week, respectively. The interior surface loading rates of dust were higher at the side streets than at main streets although the interior surface mass concentrations and loading rates of the metals were higher at the main streets than at side streets. Levels were higher in older homes and smoking homes than in new homes and non-smoking homes. Surface Pb per area in all homes exceeded the US EPA and US HUD guidelines (40 μg ft-2) of interior floor Pb dust wipe. Significant positive correlation coefficients were found between interior surface loading rates of metals and dust; among surface loading rates of metals; and among metals’ surface mass concentration.