Chemical Composition, Characterization and Factors Affecting Household Dust (<20 μm) in Greater Cairo, Egypt

Adverse health and environmental effects of household dust are derived from their chemical composition and properties. In this study, household, stairs and entryway dust (<20 μm) samples from homes located in urban, residential and residential near to industrial area in Greater Cairo during summer 2013 were collected to study their chemical composition, characterization and factors affecting them. Results indicate that the levels of measured anions and cations were higher in the household compared to stairs and entryway dust. The highest concentration of 2 4 SO − , 3 NO − , Cl−, 4 NH + , Na+, K+, Ca2+ and Mg2+ in the household and entryway dust was found in urban area. 2 4 SO − was abundant in household, entryway and stairs dust followed by Cl− and 3 NO − . Its average concentrations were 21.38, 14.57 and 15.83 mg/g, respectively. The household/entryway (I/O) concentration ratios of measured ion components indicate that these species might derive from indoor sources, although outdoor sources could be present as well. pH values of household, stairs and entryway dust ranged from 6.43 to 8.53, indicating that these dusts brought a large amount of crustal species, and might alleviate the tendency of acidification. The relationships between the concentrations of acidic components ( 3 NO − and 2 4 SO − ) and basic components ( 4 NH + , Ca2+ and Mg2+) in household, stairs and entryway dust confirm that the acidity of dust is neutralized. Ca2+ and 4 NH + in household and stairs dust and Ca2+ and Mg2 + in entryway dust are the most dominant neutralization substances. Corresponding author.