Soil samples and dust wipes were analysed by NMI for As, Ag, Cd, Pb and Zn.
Soil samples were sieved to o2 mm prior to digestion. Soil samples (0.5 g) were
digested in a 1:1 ratio of nitric acid and hydrochloric acid (Evans, 2012). Dust wipes
were digested in a 3:1 ratio of aqua regia (Evans, 2013). Soil samples and dust
wipes were measured for their metal concentrations using a Varian 730-ES ICP-OES
and Perkin Elmer Elan DRC II ICP-MS. Reagent blanks, dust wipe blanks, duplicates,
matrix spike and reference material AGAL-10 (Hawkesbury River Sediment) were
also analysed to verify sample data quality.
Lead isotopic compositions of selected samples (n¼11) were determined using
a PerkinElmer Elan DRC IIS ICP-MS after optimising sample concentrations.
Analyses were conducted with concentration-matched measurements of NIST
SRM 981 bracketing each sample, which were used to correct for isotopic mass
fractionation.