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Field site comparison of MOUDI observations of Pb and As concentrations summed according to two particle size fractions: < 1 μm and > 1 μm. Urban sites samples were collected for 96 hours on the following dates: Sydney – February 14, 2012; and Tucson – October 14, 2010. WHO guidelines: Pb – 500 ng/m3; As – 6.6 ng/m3 excess lifetime risk level 1:100,000.
