Stable Lead Isotopic Ratios as Indicator of Urban Geochemical Processes

The study is aimed to apply the Pb isotope fingerprinting technique for tracing pollution of urban surface deposited sediment (USDS). USDS reflect changes in the geochemical conditions occurring in the environment. USDS samples were collected in residential areas with multistory buildings in Russian cities: Magnitogorsk, Nizhny Tagil, Tyumen, Ufa, and Chelyabinsk. Elements concentrations and stable Pb isotopic ratios were measured in the samples. The reconstruction of the initial geochemical baseline (IGB) relationship between potentially harmful element (PHE) Pb and conservative lithogenic element (CE) Fe was carried out for USDS sample populations in the cities. The IGB reconstruction divided USDS sample populations into the groups of 'polluted' and 'unpolluted' with Pb samples. Analysis of elements concentrations and Pb isotope ratios in the groups of USDS samples showed different trends in altering geochemical conditions for metals in the surveyed cities. The USDS is characterized by a decrease in the isotope ratios of 206Pb/204Pb and 208Pb/204Pb as a result of soil pollution by vehicles during the period of using leaded gasoline. © Published under licence by IOP Publishing Ltd.The reported study was funded by RFBR, project No 19-35-60011. Pb isotope analysis was carried out at the Geoanalyst Center for collective Use of the Ural Branch of the Russian Academy of Sciences. The work of Chervyakovskaya M. and Streletskaya M. was paid from the project No AAAA-A18-118053090045-8 of the State task of the IGG UB RAS